From 1b0d946d6f08bd39211385bc703a440911b41e46 Mon Sep 17 00:00:00 2001 From: Pauli Virtanen Date: Sat, 13 Jun 2026 21:43:37 +0300 Subject: [PATCH 01/20] Bluetooth: hci_uart: clear HCI_UART_SENDING when write_work is canceled HCI_UART_SENDING bit in tx_state means write_work is pending and blocks queueing it again. Currently this bit is not cleared when canceling the work in hci_uart_close(), which blocks future writes when device is reopened later if write_work was pending. Fix by clearing HCI_UART_SENDING when canceling the work. Also make clearing of tx_skb safe by using disable_work_sync + enable_work instead of just cancel_work_sync. hci_uart_flush() purges the proto tx queue so we can cancel the pending write_work there, instead of doing it just in hci_uart_close(). Re-enable and possibly requeue the work after queue flush. Fixes: c1bb9336ae6b ("Bluetooth: hci_uart: fix UAFs and race conditions in close and init paths") Link: https://lore.kernel.org/linux-bluetooth/07e0a28650773abec711ee492fdb1bf5d21a6c98.camel@iki.fi/ Cc: stable@vger.kernel.org Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/hci_ldisc.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index 47f4902b40b4..2ad42c3bbaac 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -239,6 +239,8 @@ static int hci_uart_flush(struct hci_dev *hdev) BT_DBG("hdev %p tty %p", hdev, tty); + disable_work_sync(&hu->write_work); + if (hu->tx_skb) { kfree_skb(hu->tx_skb); hu->tx_skb = NULL; } @@ -254,6 +256,14 @@ static int hci_uart_flush(struct hci_dev *hdev) percpu_up_read(&hu->proto_lock); + /* Resume TX. Also reschedule in case work was queued concurrently; + * this may schedule write_work although there's nothing to do. + */ + enable_work(&hu->write_work); + clear_bit(HCI_UART_SENDING, &hu->tx_state); + if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state)) + hci_uart_tx_wakeup(hu); + return 0; } @@ -271,12 +281,8 @@ static int hci_uart_open(struct hci_dev *hdev) /* Close device */ static int hci_uart_close(struct hci_dev *hdev) { - struct hci_uart *hu = hci_get_drvdata(hdev); - BT_DBG("hdev %p", hdev); - cancel_work_sync(&hu->write_work); - hci_uart_flush(hdev); hdev->flush = NULL; return 0; From d38eaf611839b85ade3dd3db309dbc8aaaaf0095 Mon Sep 17 00:00:00 2001 From: Luiz Augusto von Dentz Date: Fri, 12 Jun 2026 10:21:09 -0400 Subject: [PATCH 02/20] Bluetooth: 6lowpan: Fix using chan->conn as indication to no remote netdev b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") don't reset the chan->conn to NULL anymore making the bt# netdev not be remove once the last l2cap_chan_del is removed. Instead of restoring the original behavior this remove the logic of keeping the interface after the last channel is removed because it never worked as intended and the l2cap_chan_del always detach its l2cap_conn which results in always removing the channel anyway. Fixes: b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/6lowpan.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index cb1e329d66fd..962e0e885105 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -797,20 +797,10 @@ static void chan_close_cb(struct l2cap_chan *chan) struct lowpan_btle_dev *dev = NULL; struct lowpan_peer *peer; int err = -ENOENT; - bool last = false, remove = true; + bool last = false; BT_DBG("chan %p conn %p", chan, chan->conn); - if (chan->conn && chan->conn->hcon) { - if (!is_bt_6lowpan(chan->conn->hcon)) - return; - - /* If conn is set, then the netdev is also there and we should - * not remove it. - */ - remove = false; - } - spin_lock(&devices_lock); list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { @@ -837,10 +827,8 @@ static void chan_close_cb(struct l2cap_chan *chan) ifdown(dev->netdev); - if (remove) { - INIT_WORK(&entry->delete_netdev, delete_netdev); - schedule_work(&entry->delete_netdev); - } + INIT_WORK(&entry->delete_netdev, delete_netdev); + schedule_work(&entry->delete_netdev); } else { spin_unlock(&devices_lock); } From fa85d985f614bc3feb343000f14a1072e99b0df1 Mon Sep 17 00:00:00 2001 From: Samuel Page Date: Mon, 15 Jun 2026 16:09:22 +0100 Subject: [PATCH 03/20] Bluetooth: MGMT: Fix UAF of hci_conn_params in add_device_complete add_device_complete() runs from the hci_cmd_sync_work kworker, which holds only hci_req_sync_lock and *not* hci_dev_lock. It calls hci_conn_params_lookup() and then dereferences the returned object (params->flags) without taking hci_dev_lock: params = hci_conn_params_lookup(hdev, &cp->addr.bdaddr, le_addr_type(cp->addr.type)); ... device_flags_changed(NULL, hdev, &cp->addr.bdaddr, cp->addr.type, hdev->conn_flags, params ? params->flags : 0); hci_conn_params_lookup() walks hdev->le_conn_params and is documented to require hdev->lock. A concurrent MGMT_OP_REMOVE_DEVICE (remove_device()), which does run under hci_dev_lock, can call hci_conn_params_free() to list_del() and kfree() the very object the lookup returned, so the subsequent params->flags read touches freed memory [0]. Hold hci_dev_lock() across the hci_conn_params_lookup() and the read of params->flags (and the matching event emission) so the lookup result cannot be freed by a concurrent remove_device() before it is used, honouring the locking contract of hci_conn_params_lookup(). [0]: (trailing page/memory-state dump trimmed) BUG: KASAN: slab-use-after-free in add_device_complete+0x358/0x3d8 net/bluetooth/mgmt.c:7671 Read of size 1 at addr ffff000017ab26c1 by task kworker/u9:8/388 CPU: 1 UID: 0 PID: 388 Comm: kworker/u9:8 Not tainted 7.0.11 #20 PREEMPT Hardware name: linux,dummy-virt (DT) Workqueue: hci0 hci_cmd_sync_work Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xb4/0xd4 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x118/0x5d8 mm/kasan/report.c:482 kasan_report+0xb0/0xf4 mm/kasan/report.c:595 __asan_report_load1_noabort+0x20/0x2c mm/kasan/report_generic.c:378 add_device_complete+0x358/0x3d8 net/bluetooth/mgmt.c:7671 hci_cmd_sync_work+0x14c/0x240 net/bluetooth/hci_sync.c:334 process_one_work+0x628/0xd38 kernel/workqueue.c:3289 process_scheduled_works kernel/workqueue.c:3372 [inline] worker_thread+0x7a8/0xac0 kernel/workqueue.c:3453 kthread+0x39c/0x444 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Allocated by task 3401: kasan_save_stack+0x3c/0x64 mm/kasan/common.c:57 kasan_save_track+0x20/0x3c mm/kasan/common.c:78 kasan_save_alloc_info+0x40/0x54 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xd4/0xd8 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x1b0/0x458 mm/slub.c:5385 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] hci_conn_params_add+0x10c/0x4b0 net/bluetooth/hci_core.c:2279 hci_conn_params_set net/bluetooth/mgmt.c:5162 [inline] add_device+0x5b4/0xa54 net/bluetooth/mgmt.c:7755 hci_mgmt_cmd net/bluetooth/hci_sock.c:1721 [inline] hci_sock_sendmsg+0x10b4/0x1dd0 net/bluetooth/hci_sock.c:1841 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xe0/0x128 net/socket.c:742 sock_write_iter+0x250/0x390 net/socket.c:1195 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x66c/0xab0 fs/read_write.c:688 ksys_write+0x1fc/0x24c fs/read_write.c:740 __do_sys_write fs/read_write.c:751 [inline] __se_sys_write fs/read_write.c:748 [inline] __arm64_sys_write+0x70/0xa4 fs/read_write.c:748 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x84/0x2a8 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xe4/0x294 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x44/0x5c arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0xac arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Freed by task 3740: kasan_save_stack+0x3c/0x64 mm/kasan/common.c:57 kasan_save_track+0x20/0x3c mm/kasan/common.c:78 kasan_save_free_info+0x4c/0x74 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x88/0xb8 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6170 [inline] kfree+0x14c/0x458 mm/slub.c:6488 hci_conn_params_free+0x288/0x484 net/bluetooth/hci_core.c:2312 remove_device+0x4b0/0x968 net/bluetooth/mgmt.c:7919 hci_mgmt_cmd net/bluetooth/hci_sock.c:1721 [inline] hci_sock_sendmsg+0x10b4/0x1dd0 net/bluetooth/hci_sock.c:1841 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xe0/0x128 net/socket.c:742 sock_write_iter+0x250/0x390 net/socket.c:1195 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x66c/0xab0 fs/read_write.c:688 ksys_write+0x1fc/0x24c fs/read_write.c:740 __do_sys_write fs/read_write.c:751 [inline] __se_sys_write fs/read_write.c:748 [inline] __arm64_sys_write+0x70/0xa4 fs/read_write.c:748 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x84/0x2a8 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xe4/0x294 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x44/0x5c arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0xac arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Fixes: 1e2e3044c1bc ("Bluetooth: MGMT: Fix MGMT_OP_ADD_DEVICE invalid device flags") Cc: stable@vger.kernel.org Assisted-by: Bynario AI Signed-off-by: Samuel Page Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/mgmt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index d23ca1dd0893..dc55763f9e58 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -7658,6 +7658,8 @@ static void add_device_complete(struct hci_dev *hdev, void *data, int err) if (!err) { struct hci_conn_params *params; + hci_dev_lock(hdev); + params = hci_conn_params_lookup(hdev, &cp->addr.bdaddr, le_addr_type(cp->addr.type)); @@ -7666,6 +7668,7 @@ static void add_device_complete(struct hci_dev *hdev, void *data, int err) device_flags_changed(NULL, hdev, &cp->addr.bdaddr, cp->addr.type, hdev->conn_flags, params ? params->flags : 0); + hci_dev_unlock(hdev); } mgmt_cmd_complete(cmd->sk, hdev->id, MGMT_OP_ADD_DEVICE, From d5541eb148da72d5e0a1bca8ecd171f9fc8b366f Mon Sep 17 00:00:00 2001 From: Muhammad Bilal Date: Sun, 21 Jun 2026 21:23:05 +0500 Subject: [PATCH 04/20] Bluetooth: ISO: avoid NULL deref of conn in iso_conn_big_sync() iso_conn_big_sync() drops the socket lock to call hci_get_route() and then re-acquires it, but dereferences iso_pi(sk)->conn->hcon afterwards without re-checking that conn is still valid. While the lock is dropped, the connection can be torn down under the same socket lock: iso_disconn_cfm() -> iso_conn_del() -> iso_chan_del() sets iso_pi(sk)->conn to NULL (and the broadcast teardown path can also clear conn->hcon on its own). When iso_conn_big_sync() re-acquires the lock and reads conn->hcon, conn may be NULL, causing a NULL pointer dereference (hcon is the first member of struct iso_conn). This path is reached from iso_sock_recvmsg() for a PA-sync broadcast sink socket (BT_SK_DEFER_SETUP | BT_SK_PA_SYNC), so the dropped-lock window can race with connection teardown driven by controller events. Re-validate iso_pi(sk)->conn and its hcon after re-acquiring the socket lock and bail out if the connection went away, as already done in the sibling iso_sock_rebind_bc(). Fixes: 7a17308c17880d ("Bluetooth: iso: Fix circular lock in iso_conn_big_sync") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/iso.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index 793a481d7066..cd7c7c9ea4fc 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -1590,6 +1590,7 @@ static void iso_conn_big_sync(struct sock *sk) { int err; struct hci_dev *hdev; + struct iso_conn *conn; bdaddr_t src, dst; u8 src_type; @@ -1612,8 +1613,17 @@ static void iso_conn_big_sync(struct sock *sk) hci_dev_lock(hdev); lock_sock(sk); + /* The socket lock was dropped for hci_get_route(), so the connection + * may have been torn down meanwhile: iso_chan_del() clears conn and + * the broadcast teardown path can clear conn->hcon on its own. Check + * both before dereferencing conn->hcon. + */ + conn = iso_pi(sk)->conn; + if (!conn || !conn->hcon) + goto unlock; + if (!test_and_set_bit(BT_SK_BIG_SYNC, &iso_pi(sk)->flags)) { - err = hci_conn_big_create_sync(hdev, iso_pi(sk)->conn->hcon, + err = hci_conn_big_create_sync(hdev, conn->hcon, &iso_pi(sk)->qos, iso_pi(sk)->sync_handle, iso_pi(sk)->bc_num_bis, @@ -1622,6 +1632,7 @@ static void iso_conn_big_sync(struct sock *sk) bt_dev_err(hdev, "hci_big_create_sync: %d", err); } +unlock: release_sock(sk); hci_dev_unlock(hdev); hci_dev_put(hdev); From 2641a9e0a1dd4af2e21995470a21d55dd35e5203 Mon Sep 17 00:00:00 2001 From: Runyu Xiao Date: Wed, 17 Jun 2026 23:36:13 +0800 Subject: [PATCH 05/20] Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for pending_rx_work. process_pending_rx() takes the same mutex, so teardown can deadlock against the worker it is flushing. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the l2cap_conn_ready() -> queue_work(..., &conn->pending_rx_work) submit path, the l2cap_conn_del() -> cancel_work_sync(&conn->pending_rx_work) teardown path, and the process_pending_rx() -> mutex_lock(&conn->lock) worker edge. Lockdep reported: WARNING: possible circular locking dependency detected process_pending_rx+0x21/0x2a [vuln_msv] l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv] *** DEADLOCK *** Cancel pending_rx_work before taking conn->lock, matching the existing lock-before-drain ordering used for the two delayed works in the same teardown path. The pending_rx queue is still purged after the work has been cancelled and conn->lock has been acquired. Fixes: 7ab56c3a6ecc ("Bluetooth: Fix deadlock in l2cap_conn_del()") Cc: stable@vger.kernel.org Signed-off-by: Runyu Xiao Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/l2cap_core.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 62133eef9d2f..036d887dec34 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -1775,19 +1775,13 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err) disable_delayed_work_sync(&conn->info_timer); disable_delayed_work_sync(&conn->id_addr_timer); + cancel_work_sync(&conn->pending_rx_work); + mutex_lock(&conn->lock); kfree_skb(conn->rx_skb); skb_queue_purge(&conn->pending_rx); - - /* We can not call flush_work(&conn->pending_rx_work) here since we - * might block if we are running on a worker from the same workqueue - * pending_rx_work is waiting on. - */ - if (work_pending(&conn->pending_rx_work)) - cancel_work_sync(&conn->pending_rx_work); - ida_destroy(&conn->tx_ida); l2cap_unregister_all_users(conn); From 687617555cedfb74c9e3cb85d759b908dcb17856 Mon Sep 17 00:00:00 2001 From: Muhammad Bilal Date: Sun, 21 Jun 2026 00:56:35 +0500 Subject: [PATCH 06/20] Bluetooth: L2CAP: validate option length before reading conf opt value l2cap_get_conf_opt() derives the option length from the attacker-controlled opt->len field and immediately dereferences opt->val (as u8, get_unaligned_le16() or get_unaligned_le32(), or a raw pointer for the default case) before any caller has confirmed that opt->len bytes are present in the buffer. The callers (l2cap_parse_conf_req(), l2cap_parse_conf_rsp() and l2cap_conf_rfc_get()) only detect a malformed option afterwards, once the running length has gone negative, by which point the out-of-bounds read has already executed. An existing post-hoc length check keeps the garbage value from being consumed, so this is not a data leak in the current control flow. It is still a validate-after-use ordering bug: up to 4 bytes are read past the end of the buffer before it is known to contain them, and it is fragile to future changes in the callers. Fix it at the source. Pass the end of the buffer into l2cap_get_conf_opt() and refuse to touch opt->val unless the full option (header + value) fits. Each caller computes an end pointer once before the loop and checks the return value directly instead of inferring the error from a negative length. Fixes: 7c9cbd0b5e38 ("Bluetooth: Verify that l2cap_get_conf_opt provides large enough buffer") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/l2cap_core.c | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 036d887dec34..a1d249f42be7 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -3045,13 +3045,24 @@ static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code, return NULL; } -static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen, - unsigned long *val) +static inline int l2cap_get_conf_opt(void **ptr, void *end, int *type, + int *olen, unsigned long *val) { struct l2cap_conf_opt *opt = *ptr; int len; + /* opt->len is attacker-controlled. Validate that the full option + * (header + value) actually fits in the buffer before touching + * opt->val, otherwise the switch below reads past the end of the + * caller's buffer. + */ + if (end - *ptr < L2CAP_CONF_OPT_SIZE) + return -EINVAL; + len = L2CAP_CONF_OPT_SIZE + opt->len; + if (end - *ptr < len) + return -EINVAL; + *ptr += len; *type = opt->type; @@ -3423,6 +3434,7 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data void *ptr = rsp->data; void *endptr = data + data_size; void *req = chan->conf_req; + void *req_end = req + chan->conf_len; int len = chan->conf_len; int type, hint, olen; unsigned long val; @@ -3436,9 +3448,11 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data BT_DBG("chan %p", chan); while (len >= L2CAP_CONF_OPT_SIZE) { - len -= l2cap_get_conf_opt(&req, &type, &olen, &val); - if (len < 0) + int ret = l2cap_get_conf_opt(&req, req_end, &type, &olen, &val); + + if (ret < 0) break; + len -= ret; hint = type & L2CAP_CONF_HINT; type &= L2CAP_CONF_MASK; @@ -3666,6 +3680,7 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, struct l2cap_conf_req *req = data; void *ptr = req->data; void *endptr = data + size; + void *rsp_end = rsp + len; int type, olen; unsigned long val; struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; @@ -3674,9 +3689,11 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data); while (len >= L2CAP_CONF_OPT_SIZE) { - len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); - if (len < 0) + int ret = l2cap_get_conf_opt(&rsp, rsp_end, &type, &olen, &val); + + if (ret < 0) break; + len -= ret; switch (type) { case L2CAP_CONF_MTU: @@ -3927,6 +3944,7 @@ static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len) { int type, olen; unsigned long val; + void *rsp_end = rsp + len; /* Use sane default values in case a misbehaving remote device * did not send an RFC or extended window size option. */ @@ -3945,9 +3963,11 @@ static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len) return; while (len >= L2CAP_CONF_OPT_SIZE) { - len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val); - if (len < 0) + int ret = l2cap_get_conf_opt(&rsp, rsp_end, &type, &olen, &val); + + if (ret < 0) break; + len -= ret; switch (type) { case L2CAP_CONF_RFC: From badff6c3bed8923a1257a853f137d447976eec30 Mon Sep 17 00:00:00 2001 From: Maoyi Xie Date: Wed, 17 Jun 2026 16:36:52 +0800 Subject: [PATCH 07/20] Bluetooth: btnxpuart: Fix out-of-bounds firmware read in nxp_recv_fw_req_v3() During the v3 firmware download the controller sends a v3_data_req with a 32 bit offset and a 16 bit len. nxp_recv_fw_req_v3() checks only the lower bound of the offset and then sends firmware from that offset. nxpdev->fw_dnld_v3_offset = offset - nxpdev->fw_v3_offset_correction; serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data + nxpdev->fw_dnld_v3_offset, len); Nothing checks that fw_dnld_v3_offset + len stays within nxpdev->fw->size, so a controller that asks for an offset or length past the firmware image makes the driver read past the end of nxpdev->fw->data and send that memory back over UART. nxp_recv_fw_req_v1() already bounds the same write. Add the equivalent check to the v3 path, reject the request when it falls outside the firmware image, and zero len on the error path so the fw_v3_prev_sent bookkeeping at free_skb stays consistent. Fixes: 689ca16e5232 ("Bluetooth: NXP: Add protocol support for NXP Bluetooth chipsets") Suggested-by: Neeraj Sanjay Kale Reviewed-by: Neeraj Sanjay Kale Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/btnxpuart.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c index e7036a48ce48..6a1cffe08d5f 100644 --- a/drivers/bluetooth/btnxpuart.c +++ b/drivers/bluetooth/btnxpuart.c @@ -1267,6 +1267,12 @@ static int nxp_recv_fw_req_v3(struct hci_dev *hdev, struct sk_buff *skb) } nxpdev->fw_dnld_v3_offset = offset - nxpdev->fw_v3_offset_correction; + if (nxpdev->fw_dnld_v3_offset >= nxpdev->fw->size || + len > nxpdev->fw->size - nxpdev->fw_dnld_v3_offset) { + bt_dev_err(hdev, "FW download out of bounds, ignoring request"); + len = 0; + goto free_skb; + } serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data + nxpdev->fw_dnld_v3_offset, len); From 12917f591cea1af36087dba5b9ec888652f0b42a Mon Sep 17 00:00:00 2001 From: Siwei Zhang Date: Mon, 15 Jun 2026 11:33:05 -0400 Subject: [PATCH 08/20] Bluetooth: hci_conn: Fix null ptr deref in hci_abort_conn() hci_abort_conn() read hci_skb_event(hdev->sent_cmd) when a connection was pending, but hdev->sent_cmd can be NULL while req_status is still HCI_REQ_PEND, leading to a NULL pointer dereference and a general protection fault from the hci_rx_work() receive path. Instead of inspecting hdev->sent_cmd, track the in-flight create connection command with a new per-connection HCI_CONN_CREATE flag and route all cancellation through hci_cancel_connect_sync(), which dispatches to a dedicated per-type cancel function. The create command is in exactly one of two states: still queued, or in flight. The cancel function holds cmd_sync_work_lock across the whole decision: the worker takes this lock to dequeue every entry, so while it is held a queued command cannot start running and an in-flight command cannot complete and let the next command become pending. This keeps the flag test and hci_cmd_sync_cancel() atomic with respect to the worker, so a queued command is simply dequeued, and an in-flight command owned by this connection is cancelled without the risk of cancelling an unrelated command that became pending in the meantime. CIS uses the same flag mechanism via HCI_CONN_CREATE_CIS but cannot be dequeued per-connection. hci_acl_create_conn_sync() and hci_le_create_conn_sync() clear HCI_CONN_CREATE after the create command completes, but the command status handler can free conn via hci_conn_del() (for example when the controller rejects the connection) while the worker is still blocked on the connection complete event. Hold a reference on conn across the create command so the flag can be cleared without a use-after-free. Fixes: a13f316e90fd ("Bluetooth: hci_conn: Consolidate code for aborting connections") Cc: stable@vger.kernel.org Suggested-by: XIAO WU Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Siwei Zhang Signed-off-by: Luiz Augusto von Dentz --- include/net/bluetooth/hci_core.h | 1 + net/bluetooth/hci_conn.c | 21 +---- net/bluetooth/hci_sync.c | 137 +++++++++++++++++++++++++++---- 3 files changed, 125 insertions(+), 34 deletions(-) diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index 7e15da47fe3a..4ca09298e11a 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -985,6 +985,7 @@ enum { HCI_CONN_AUTH_FAILURE, HCI_CONN_PER_ADV, HCI_CONN_BIG_CREATED, + HCI_CONN_CREATE, HCI_CONN_CREATE_CIS, HCI_CONN_CREATE_BIG_SYNC, HCI_CONN_BIG_SYNC, diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index c335372e4062..1966cd153d97 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -3178,26 +3178,11 @@ int hci_abort_conn(struct hci_conn *conn, u8 reason) conn->abort_reason = reason; - /* If the connection is pending check the command opcode since that - * might be blocking on hci_cmd_sync_work while waiting its respective - * event so we need to hci_cmd_sync_cancel to cancel it. - * - * hci_connect_le serializes the connection attempts so only one - * connection can be in BT_CONNECT at time. + /* Cancel the connect attempt. A return of 0 means the create command + * was still queued and got dequeued, so there is nothing to disconnect. */ - if (conn->state == BT_CONNECT && READ_ONCE(hdev->req_status) == HCI_REQ_PEND) { - switch (hci_skb_event(hdev->sent_cmd)) { - case HCI_EV_CONN_COMPLETE: - case HCI_EV_LE_CONN_COMPLETE: - case HCI_EV_LE_ENHANCED_CONN_COMPLETE: - case HCI_EVT_LE_CIS_ESTABLISHED: - hci_cmd_sync_cancel(hdev, ECANCELED); - break; - } - /* Cancel connect attempt if still queued/pending */ - } else if (!hci_cancel_connect_sync(hdev, conn)) { + if (!hci_cancel_connect_sync(hdev, conn)) return 0; - } /* Run immediately if on cmd_sync_work since this may be called * as a result to MGMT_OP_DISCONNECT/MGMT_OP_UNPAIR which does diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index 3be8c3581c6c..c896d4edd013 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -6633,6 +6633,11 @@ static int hci_le_create_conn_sync(struct hci_dev *hdev, void *data) bt_dev_dbg(hdev, "conn %p", conn); + /* Hold a reference so conn stays valid for the HCI_CONN_CREATE + * clear_bit() at done. + */ + hci_conn_get(conn); + clear_bit(HCI_CONN_SCANNING, &conn->flags); conn->state = BT_CONNECT; @@ -6645,6 +6650,7 @@ static int hci_le_create_conn_sync(struct hci_dev *hdev, void *data) hdev->le_scan_type == LE_SCAN_ACTIVE && !hci_dev_test_flag(hdev, HCI_LE_SIMULTANEOUS_ROLES)) { hci_conn_del(conn); + hci_conn_put(conn); return -EBUSY; } @@ -6690,6 +6696,12 @@ static int hci_le_create_conn_sync(struct hci_dev *hdev, void *data) &own_addr_type); if (err) goto done; + + /* Mark create connection in flight so hci_cancel_connect_sync() can + * cancel it while blocking on the connection complete event. + */ + set_bit(HCI_CONN_CREATE, &conn->flags); + /* Send command LE Extended Create Connection if supported */ if (use_ext_conn(hdev)) { err = hci_le_ext_create_conn_sync(hdev, conn, own_addr_type); @@ -6725,11 +6737,14 @@ static int hci_le_create_conn_sync(struct hci_dev *hdev, void *data) conn->conn_timeout, NULL); done: + clear_bit(HCI_CONN_CREATE, &conn->flags); + if (err == -ETIMEDOUT) hci_le_connect_cancel_sync(hdev, conn, 0x00); /* Re-enable advertising after the connection attempt is finished. */ hci_resume_advertising_sync(hdev); + hci_conn_put(conn); return err; } @@ -7004,10 +7019,25 @@ static int hci_acl_create_conn_sync(struct hci_dev *hdev, void *data) else cp.role_switch = 0x00; - return __hci_cmd_sync_status_sk(hdev, HCI_OP_CREATE_CONN, - sizeof(cp), &cp, - HCI_EV_CONN_COMPLETE, - conn->conn_timeout, NULL); + /* Hold a reference so conn stays valid for the HCI_CONN_CREATE + * clear_bit() below. + */ + hci_conn_get(conn); + + /* Mark create connection in flight so hci_cancel_connect_sync() can + * cancel it while blocking on the connection complete event. + */ + set_bit(HCI_CONN_CREATE, &conn->flags); + + err = __hci_cmd_sync_status_sk(hdev, HCI_OP_CREATE_CONN, + sizeof(cp), &cp, + HCI_EV_CONN_COMPLETE, + conn->conn_timeout, NULL); + + clear_bit(HCI_CONN_CREATE, &conn->flags); + hci_conn_put(conn); + + return err; } int hci_connect_acl_sync(struct hci_dev *hdev, struct hci_conn *conn) @@ -7059,22 +7089,97 @@ int hci_connect_le_sync(struct hci_dev *hdev, struct hci_conn *conn) return (err == -EEXIST) ? 0 : err; } -int hci_cancel_connect_sync(struct hci_dev *hdev, struct hci_conn *conn) +static int hci_acl_cancel_create_conn_sync(struct hci_dev *hdev, + struct hci_conn *conn) { - if (conn->state != BT_OPEN) - return -EINVAL; + struct hci_cmd_sync_work_entry *entry; + int err = -EBUSY; - switch (conn->type) { - case ACL_LINK: - return !hci_cmd_sync_dequeue_once(hdev, - hci_acl_create_conn_sync, - conn, NULL); - case LE_LINK: - return !hci_cmd_sync_dequeue_once(hdev, hci_le_create_conn_sync, - conn, create_le_conn_complete); + /* cmd_sync_work_lock makes the HCI_CONN_CREATE test and the cancel + * atomic against the worker, which takes this lock to dequeue every + * entry: while it is held no other command can become pending, so + * hci_cmd_sync_cancel() cannot cancel an unrelated command. + */ + mutex_lock(&hdev->cmd_sync_work_lock); + + /* In flight: this connection owns the pending request, cancel it. */ + if (test_bit(HCI_CONN_CREATE, &conn->flags)) { + hci_cmd_sync_cancel(hdev, ECANCELED); + goto unlock; } - return -ENOENT; + /* Still queued: a successful dequeue means it never started, so there + * is nothing to disconnect. + */ + entry = _hci_cmd_sync_lookup_entry(hdev, hci_acl_create_conn_sync, conn, + NULL); + if (entry) { + _hci_cmd_sync_cancel_entry(hdev, entry, -ECANCELED); + err = 0; + } + +unlock: + mutex_unlock(&hdev->cmd_sync_work_lock); + return err; +} + +static int hci_le_cancel_create_conn_sync(struct hci_dev *hdev, + struct hci_conn *conn) +{ + struct hci_cmd_sync_work_entry *entry; + int err = -EBUSY; + + /* cmd_sync_work_lock keeps the HCI_CONN_CREATE test and the cancel + * atomic against the cmd_sync worker. + */ + mutex_lock(&hdev->cmd_sync_work_lock); + + if (test_bit(HCI_CONN_CREATE, &conn->flags)) { + hci_cmd_sync_cancel(hdev, ECANCELED); + goto unlock; + } + + entry = _hci_cmd_sync_lookup_entry(hdev, hci_le_create_conn_sync, conn, + create_le_conn_complete); + if (entry) { + _hci_cmd_sync_cancel_entry(hdev, entry, -ECANCELED); + err = 0; + } + +unlock: + mutex_unlock(&hdev->cmd_sync_work_lock); + return err; +} + +static int hci_cis_cancel_create_conn_sync(struct hci_dev *hdev, + struct hci_conn *conn) +{ + /* LE Create CIS is shared by the whole CIG and cannot be dequeued + * per-connection, so only an in-flight command can be cancelled. + * cmd_sync_work_lock keeps the test and the cancel atomic against the + * cmd_sync worker. + */ + mutex_lock(&hdev->cmd_sync_work_lock); + + if (test_bit(HCI_CONN_CREATE_CIS, &conn->flags)) + hci_cmd_sync_cancel(hdev, ECANCELED); + + mutex_unlock(&hdev->cmd_sync_work_lock); + return -EBUSY; +} + +int hci_cancel_connect_sync(struct hci_dev *hdev, struct hci_conn *conn) +{ + switch (conn->type) { + case ACL_LINK: + return hci_acl_cancel_create_conn_sync(hdev, conn); + case LE_LINK: + return hci_le_cancel_create_conn_sync(hdev, conn); + case CIS_LINK: + return hci_cis_cancel_create_conn_sync(hdev, conn); + default: + return -ENOENT; + } } int hci_le_conn_update_sync(struct hci_dev *hdev, struct hci_conn *conn, From 352a59dc1f4a41314b6f827c17e16af7ca88271a Mon Sep 17 00:00:00 2001 From: Cen Zhang Date: Wed, 24 Jun 2026 00:12:29 +0800 Subject: [PATCH 09/20] Bluetooth: 6lowpan: avoid untracked enable work lowpan_enable_set() allocates a temporary work item and schedules do_enable_set() on system_wq, then returns to debugfs. The debugfs active operation has ended at that point, but the worker still executes module text and manipulates enable_6lowpan and listen_chan. bt_6lowpan_exit() removes the debugfs files and immediately closes and puts listen_chan. It has no pointer to the queued work item, so it cannot cancel or flush it before tearing down the state that the worker uses. The buggy scenario involves two paths, with each column showing the order within that path: debugfs enable write module exit 1. lowpan_enable_set() allocates 1. bt_6lowpan_exit() removes set_enable work the debugfs file 2. schedule_work() queues 2. bt_6lowpan_exit() closes do_enable_set() and puts listen_chan 3. the write operation returns 3. module teardown can continue 4. do_enable_set() later runs against stale state Run the enable state transition synchronously in lowpan_enable_set() instead. The simple debugfs setter can sleep, and this file already handles the 6LoWPAN control write synchronously under the same set_lock. Once the setter returns, debugfs removal covers the whole operation and exit can no longer race with an untracked work item. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in do_enable_set+0x113/0x2e0 Workqueue: events do_enable_set [bluetooth_6lowpan] The buggy address belongs to the object at ffff888109cb8000 Fixes: 90305829635d ("Bluetooth: 6lowpan: Converting rwlocks to use RCU") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/6lowpan.c | 27 ++++----------------------- 1 file changed, 4 insertions(+), 23 deletions(-) diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index 962e0e885105..c4b0a4048be2 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -1081,23 +1081,15 @@ static void disconnect_all_peers(void) } while (nchans); } -struct set_enable { - struct work_struct work; - bool flag; -}; - -static void do_enable_set(struct work_struct *work) +static void do_enable_set(bool flag) { - struct set_enable *set_enable = container_of(work, - struct set_enable, work); - - if (!set_enable->flag || enable_6lowpan != set_enable->flag) + if (!flag || enable_6lowpan != flag) /* Disconnect existing connections if 6lowpan is * disabled */ disconnect_all_peers(); - enable_6lowpan = set_enable->flag; + enable_6lowpan = flag; mutex_lock(&set_lock); if (listen_chan) { @@ -1109,22 +1101,11 @@ static void do_enable_set(struct work_struct *work) listen_chan = bt_6lowpan_listen(); mutex_unlock(&set_lock); - - kfree(set_enable); } static int lowpan_enable_set(void *data, u64 val) { - struct set_enable *set_enable; - - set_enable = kzalloc_obj(*set_enable); - if (!set_enable) - return -ENOMEM; - - set_enable->flag = !!val; - INIT_WORK(&set_enable->work, do_enable_set); - - schedule_work(&set_enable->work); + do_enable_set(!!val); return 0; } From 518aa9505fa10ea5662349e5d2efd8c9e32a820b Mon Sep 17 00:00:00 2001 From: Cen Zhang Date: Wed, 24 Jun 2026 00:12:59 +0800 Subject: [PATCH 10/20] Bluetooth: 6lowpan: hold L2CAP conn across debugfs control get_l2cap_conn() looks up an LE hci_conn under hdev protection, but then drops that protection before reading hcon->l2cap_data and before lowpan_control_write() later dereferences conn->hcon. A disconnect or device close can tear down the same L2CAP connection in that window. The buggy scenario involves two paths, with each column showing the order within that path: 6LoWPAN control write: HCI disconnect/device close: 1. get_l2cap_conn() finds hcon 1. hci_disconn_cfm() dispatches and hcon->l2cap_data. the L2CAP disconnect callback. 2. get_l2cap_conn() drops hdev 2. l2cap_conn_del() clears protection and returns conn. hcon->l2cap_data and drops the L2CAP connection reference. 3. lowpan_control_write() reads 3. hci_conn_del() removes and drops conn->hcon. the HCI connection. Take a reference to the L2CAP connection with l2cap_conn_hold_unless_zero() while hdev is still locked, and drop that reference after the debugfs command's last use of conn. This mirrors the existing L2CAP ACL receive-side handoff and keeps the connection dereferenceable after leaving hdev protection. Export the existing helper so the bluetooth_6lowpan module can use the same lifetime primitive. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in lowpan_control_write+0x374/0x520 The buggy address belongs to the object at ffff888111b9d000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of freed 1024-byte region [ffff888111b9d000, ffff888111b9d400) Read of size 8 Call trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x5f0 lowpan_control_write+0x374/0x520 (net/bluetooth/6lowpan.c:1131) srso_alias_return_thunk+0x5/0xfbef5 __virt_addr_valid+0x19f/0x330 kasan_report+0xe0/0x110 __debugfs_file_get+0xf7/0x400 full_proxy_write+0x9e/0xd0 vfs_write+0x1b0/0x810 ksys_write+0xd2/0x170 dnotify_flush+0x32/0x220 do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f Allocated by task stack: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 __kasan_kmalloc+0xaa/0xb0 l2cap_conn_add+0x45/0x520 l2cap_chan_connect+0xac6/0xd90 l2cap_sock_connect+0x216/0x350 __sys_connect+0x101/0x130 __x64_sys_connect+0x40/0x50 do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task stack: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x313/0x590 hci_conn_hash_flush+0xc0/0x140 hci_dev_close_sync+0x41a/0xb00 hci_dev_close+0x12f/0x160 hci_sock_ioctl+0x157/0x570 sock_do_ioctl+0xf7/0x210 sock_ioctl+0x32f/0x490 __x64_sys_ioctl+0xc7/0x110 do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f kasan_record_aux_stack+0xa7/0xc0 insert_work+0x32/0x100 __queue_work+0x262/0xa60 queue_work_on+0xad/0xb0 l2cap_connect_cfm+0x4ef/0x670 hci_le_remote_feat_complete_evt+0x247/0x430 hci_event_packet+0x360/0x6f0 hci_rx_work+0x2ae/0x7a0 process_one_work+0x4fd/0xbc0 worker_thread+0x2d8/0x570 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 ret_from_fork_asm+0x1a/0x30 Fixes: 6b8d4a6a0314 ("Bluetooth: 6LoWPAN: Use connected oriented channel instead of fixed one") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/6lowpan.c | 21 +++++++++++++++------ net/bluetooth/l2cap_core.c | 1 + 2 files changed, 16 insertions(+), 6 deletions(-) diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index c4b0a4048be2..e7be18a3af33 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -1017,16 +1017,19 @@ static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, hci_dev_lock(hdev); hcon = hci_conn_hash_lookup_le(hdev, addr, le_addr_type); - hci_dev_unlock(hdev); - hci_dev_put(hdev); - - if (!hcon) + if (!hcon) { + hci_dev_unlock(hdev); + hci_dev_put(hdev); return -ENOENT; + } - *conn = (struct l2cap_conn *)hcon->l2cap_data; + *conn = l2cap_conn_hold_unless_zero(hcon->l2cap_data); BT_DBG("conn %p dst %pMR type %u", *conn, &hcon->dst, hcon->dst_type); + hci_dev_unlock(hdev); + hci_dev_put(hdev); + return 0; } @@ -1154,18 +1157,22 @@ static ssize_t lowpan_control_write(struct file *fp, if (conn) { struct lowpan_peer *peer; - if (!is_bt_6lowpan(conn->hcon)) + if (!is_bt_6lowpan(conn->hcon)) { + l2cap_conn_put(conn); return -EINVAL; + } peer = lookup_peer(conn); if (peer) { BT_DBG("6LoWPAN connection already exists"); + l2cap_conn_put(conn); return -EALREADY; } BT_DBG("conn %p dst %pMR type %d user %u", conn, &conn->hcon->dst, conn->hcon->dst_type, addr_type); + l2cap_conn_put(conn); } ret = bt_6lowpan_connect(&addr, addr_type); @@ -1181,6 +1188,8 @@ static ssize_t lowpan_control_write(struct file *fp, return ret; ret = bt_6lowpan_disconnect(conn, addr_type); + if (conn) + l2cap_conn_put(conn); if (ret < 0) return ret; diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index a1d249f42be7..4ee3b9e30c65 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -7716,6 +7716,7 @@ struct l2cap_conn *l2cap_conn_hold_unless_zero(struct l2cap_conn *c) return c; } +EXPORT_SYMBOL(l2cap_conn_hold_unless_zero); int l2cap_recv_acldata(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, u16 flags) From 384a4b2fef9ffe5e270ee5558975c0504881c5fb Mon Sep 17 00:00:00 2001 From: Cen Zhang Date: Wed, 24 Jun 2026 00:13:28 +0800 Subject: [PATCH 11/20] Bluetooth: MGMT: Fix adv monitor add failure cleanup hci_add_adv_monitor() publishes a new adv_monitor in hdev->adv_monitors_idr before the powered MSFT setup step. The MSFT offload add path can then fail either locally before the controller add command completes, or in the MSFT add callback. In the current queued management add flow, hci_cmd_sync_work() still invokes mgmt_add_adv_patterns_monitor_complete() with the original pending command after msft_add_monitor_pattern() returns. The buggy scenario involves two paths, with each column showing the order within that path: MSFT add handling MGMT completion 1. insert monitor and handle 1. receive sync error 2. send MSFT add command 2. call add-monitor completion 3. callback sees bad response 3. load cmd->user_data 4. callback frees monitor 4. read monitor->handle Local MSFT setup failures have the other half of the same ownership bug: they return an error after the IDR insertion, but no later code removes the failed monitor from the IDR. Keep ownership with the pending management command until its completion. For normal management adds, the MSFT add callback now records successful controller state and returns errors to its caller. The management completion frees the monitor on non-success after copying the response handle, while resume/reregister callback-error cleanup remains in the MSFT callback. The success path keeps the existing bookkeeping. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] Call Trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x5f0 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x19f/0x330 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] kasan_report+0xe0/0x110 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 ? 0xffffffffc00d00da ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] ? hci_cmd_sync_work+0x1ab/0x210 [bluetooth] hci_cmd_sync_work+0x1c0/0x210 [bluetooth] ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] process_one_work+0x4fd/0xbc0 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __list_add_valid_or_report+0x37/0xf0 ? __pfx_hci_cmd_sync_work+0x10/0x10 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x2d8/0x570 ? __pfx_worker_thread+0x10/0x10 kthread+0x1ad/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3c9/0x540 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x2e9/0x730 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Allocated by task 471 on cpu 3 at 285.205389s: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 __kasan_kmalloc+0xaa/0xb0 add_adv_patterns_monitor_rssi+0xd5/0x230 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth] __sys_sendto+0x2bc/0x2d0 __x64_sys_sendto+0x76/0x90 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 454 on cpu 2 at 285.217112s: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x313/0x590 msft_add_monitor_sync+0x54a/0x570 [bluetooth] hci_add_adv_monitor+0x133/0x180 [bluetooth] hci_cmd_sync_work+0x187/0x210 [bluetooth] process_one_work+0x4fd/0xbc0 worker_thread+0x2d8/0x570 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 ret_from_fork_asm+0x1a/0x30 Fixes: a2a4dedf88ab ("Bluetooth: advmon offload MSFT add monitor") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/mgmt.c | 2 ++ net/bluetooth/msft.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index dc55763f9e58..733a4b70e10c 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -5375,6 +5375,8 @@ static void mgmt_add_adv_patterns_monitor_complete(struct hci_dev *hdev, if (monitor->state == ADV_MONITOR_STATE_NOT_REGISTERED) monitor->state = ADV_MONITOR_STATE_REGISTERED; hci_update_passive_scan(hdev); + } else { + hci_free_adv_monitor(hdev, monitor); } mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode, diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c index 2f008167cbaa..d7badce8746c 100644 --- a/net/bluetooth/msft.c +++ b/net/bluetooth/msft.c @@ -291,7 +291,7 @@ static int msft_le_monitor_advertisement_cb(struct hci_dev *hdev, u16 opcode, monitor->state = ADV_MONITOR_STATE_OFFLOADED; unlock: - if (status) + if (status && msft->resuming) hci_free_adv_monitor(hdev, monitor); hci_dev_unlock(hdev); From 0f8a5dcc66648b6e1458a9f3ba4c5a0463a228fc Mon Sep 17 00:00:00 2001 From: Sungwoo Kim Date: Wed, 24 Jun 2026 17:33:04 -0400 Subject: [PATCH 12/20] Bluetooth: sco: Fix a race condition in sco_sock_timeout() sco_sock_timeout() runs asynchronously and lock_sock(sk). If the socket is closing while the timer is running, it holds the same lock (lock_sock(sk)) twice, leading to a deadlock. CPU 0 CPU 1 ==================== ====================== sco_sock_close() sco_sock_timeout() lock_sock(sk) // <-- LOCK __sco_sock_close() sco_chan_del() sco_conn_put() sco_conn_free() disable_delayed_work_sync() lock(sk) // <-- SAME LOCK Fix this by moving disable_delayed_work_sync() outside of lock_sock(sk), ensuring that no lock_sock(sk) is held before sco_sock_timeout(). Lockdep splat: WARNING: possible circular locking dependency detected 6.13.0-rc4 #7 Not tainted syz-executor292/9514 is trying to acquire lock: ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire sect/v6.13-rc4/./include/linux/rcupdate.h:337 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: rcu_read_lock sect/v6.13-rc4/./include/linux/rcupdate.h:849 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: start_flush_work sect/v6.13-rc4/kernel/workqueue.c:4137 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: __flush_work+0xd1/0xc40 sect/v6.13-rc4/kernel/workqueue.c:4195 but task is already holding lock: ffff88807db3a258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock sect/v6.13-rc4/./include/net/sock.h:1623 [inline] ffff88807db3a258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_sock_close+0x25/0x100 sect/v6.13-rc4/net/bluetooth/sco.c:524 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: lock_acquire+0x1c4/0x520 sect/v6.13-rc4/kernel/locking/lockdep.c:5849 lock_sock_nested+0x48/0x130 sect/v6.13-rc4/net/core/sock.c:3622 lock_sock sect/v6.13-rc4/./include/net/sock.h:1623 [inline] sco_sock_timeout+0xbe/0x270 sect/v6.13-rc4/net/bluetooth/sco.c:158 process_one_work sect/v6.13-rc4/kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa99/0x18f0 sect/v6.13-rc4/kernel/workqueue.c:3310 worker_thread+0x8a9/0xd80 sect/v6.13-rc4/kernel/workqueue.c:3391 kthread+0x2c6/0x360 sect/v6.13-rc4/kernel/kthread.c:389 ret_from_fork+0x4e/0x80 sect/v6.13-rc4/arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 sect/v6.13-rc4/arch/x86/entry/entry_64.S:244 -> #0 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}: check_prev_add sect/v6.13-rc4/kernel/locking/lockdep.c:3161 [inline] check_prevs_add sect/v6.13-rc4/kernel/locking/lockdep.c:3280 [inline] validate_chain+0x1888/0x5760 sect/v6.13-rc4/kernel/locking/lockdep.c:3904 __lock_acquire+0x13b4/0x2120 sect/v6.13-rc4/kernel/locking/lockdep.c:5226 lock_acquire+0x1c4/0x520 sect/v6.13-rc4/kernel/locking/lockdep.c:5849 touch_work_lockdep_map sect/v6.13-rc4/kernel/workqueue.c:3909 [inline] start_flush_work sect/v6.13-rc4/kernel/workqueue.c:4163 [inline] __flush_work+0x70f/0xc40 sect/v6.13-rc4/kernel/workqueue.c:4195 __cancel_work_sync sect/v6.13-rc4/kernel/workqueue.c:4351 [inline] disable_delayed_work_sync+0xbb/0xf0 sect/v6.13-rc4/kernel/workqueue.c:4514 sco_conn_free sect/v6.13-rc4/net/bluetooth/sco.c:95 [inline] kref_put sect/v6.13-rc4/./include/linux/kref.h:65 [inline] sco_conn_put+0x18f/0x270 sect/v6.13-rc4/net/bluetooth/sco.c:107 sco_chan_del+0xe2/0x210 sect/v6.13-rc4/net/bluetooth/sco.c:236 sco_sock_close+0x8f/0x100 sect/v6.13-rc4/net/bluetooth/sco.c:526 sco_sock_release+0x62/0x2d0 sect/v6.13-rc4/net/bluetooth/sco.c:1300 __sock_release+0xe1/0x2d0 sect/v6.13-rc4/net/socket.c:640 sock_close+0x1c/0x30 sect/v6.13-rc4/net/socket.c:1408 __fput+0x2bd/0xa80 sect/v6.13-rc4/fs/file_table.c:450 __fput_sync+0x15e/0x1c0 sect/v6.13-rc4/fs/file_table.c:535 __do_sys_close sect/v6.13-rc4/fs/open.c:1554 [inline] __se_sys_close sect/v6.13-rc4/fs/open.c:1539 [inline] __x64_sys_close+0x93/0x120 sect/v6.13-rc4/fs/open.c:1539 do_syscall_x64 sect/v6.13-rc4/arch/x86/entry/common.c:52 [inline] do_syscall_64+0xee/0x210 sect/v6.13-rc4/arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: e6720779ae61 ("Bluetooth: SCO: Use kref to track lifetime of sco_conn") Acked-by: Dave Tian Signed-off-by: Sungwoo Kim Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/sco.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index fcc597be5bbd..c05f79b7aa31 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -570,10 +570,23 @@ static void __sco_sock_close(struct sock *sk) /* Must be called on unlocked socket. */ static void sco_sock_close(struct sock *sk) { + struct sco_conn *conn; + + lock_sock(sk); + conn = sco_pi(sk)->conn; + if (conn) + sco_conn_hold(conn); + release_sock(sk); + + if (conn) + disable_delayed_work_sync(&conn->timeout_work); + lock_sock(sk); - sco_sock_clear_timer(sk); __sco_sock_close(sk); release_sock(sk); + + if (conn) + sco_conn_put(conn); } static void sco_sock_init(struct sock *sk, struct sock *parent) From bb067a99a0356196c0b89a95721985485ebce5a5 Mon Sep 17 00:00:00 2001 From: Yousef Alhouseen Date: Sun, 28 Jun 2026 02:50:58 +0200 Subject: [PATCH 13/20] Bluetooth: bnep: pin L2CAP connection during netdev registration bnep_add_connection() reads the L2CAP connection without holding the channel lock, then passes its HCI device to register_netdev(). Controller teardown can clear and release that connection concurrently, leaving the network device registration path to dereference a freed parent device. Take a reference to the L2CAP connection while holding the channel lock. Retain it until register_netdev() has taken the parent device reference. Fixes: 65f53e9802db ("Bluetooth: Access BNEP session addresses through L2CAP channel") Reported-by: syzbot+fed5dce4553262f3b35c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=fed5dce4553262f3b35c Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/bnep/core.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/net/bluetooth/bnep/core.c b/net/bluetooth/bnep/core.c index add9a8f7535d..f7d88c33e23e 100644 --- a/net/bluetooth/bnep/core.c +++ b/net/bluetooth/bnep/core.c @@ -559,14 +559,18 @@ static int bnep_session(void *arg) return 0; } -static struct device *bnep_get_device(struct bnep_session *session) +static struct l2cap_conn *bnep_get_conn(struct bnep_session *session) { - struct l2cap_conn *conn = l2cap_pi(session->sock->sk)->chan->conn; + struct l2cap_chan *chan = l2cap_pi(session->sock->sk)->chan; + struct l2cap_conn *conn; - if (!conn || !conn->hcon) - return NULL; + l2cap_chan_lock(chan); + conn = chan->conn; + if (conn) + l2cap_conn_get(conn); + l2cap_chan_unlock(chan); - return &conn->hcon->dev; + return conn; } static const struct device_type bnep_type = { @@ -578,6 +582,7 @@ int bnep_add_connection(struct bnep_connadd_req *req, struct socket *sock) u32 valid_flags = BIT(BNEP_SETUP_RESPONSE); struct net_device *dev; struct bnep_session *s, *ss; + struct l2cap_conn *conn = NULL; u8 dst[ETH_ALEN], src[ETH_ALEN]; int err; @@ -637,10 +642,18 @@ int bnep_add_connection(struct bnep_connadd_req *req, struct socket *sock) bnep_set_default_proto_filter(s); #endif - SET_NETDEV_DEV(dev, bnep_get_device(s)); + conn = bnep_get_conn(s); + if (!conn) { + err = -ENOTCONN; + goto failed; + } + + SET_NETDEV_DEV(dev, &conn->hcon->dev); SET_NETDEV_DEVTYPE(dev, &bnep_type); err = register_netdev(dev); + l2cap_conn_put(conn); + conn = NULL; if (err) goto failed; @@ -662,6 +675,8 @@ int bnep_add_connection(struct bnep_connadd_req *req, struct socket *sock) return 0; failed: + if (conn) + l2cap_conn_put(conn); up_write(&bnep_session_sem); free_netdev(dev); return err; From 4bd0b274054f2679f28b70222b607bb0afc3ab9a Mon Sep 17 00:00:00 2001 From: Yousef Alhouseen Date: Sun, 28 Jun 2026 02:23:05 +0200 Subject: [PATCH 14/20] Bluetooth: fix UAF in bt_accept_dequeue() bt_accept_get() takes a temporary reference before dropping the accept queue lock. bt_accept_dequeue() currently drops that reference before bt_accept_unlink(), leaving only the queue reference. bt_accept_unlink() drops the queue reference. The subsequent sock_hold() therefore accesses freed memory if it was the final reference, as observed by KASAN during listening L2CAP socket cleanup. Retain the temporary queue-walk reference through unlink and hand it to the caller on success. Drop it explicitly on the closed and not-yet-connected paths. Fixes: ab1513597c6c ("Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()") Reported-by: syzbot+674ff7e4d7fdfd572afc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=674ff7e4d7fdfd572afc Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/af_bluetooth.c | 17 +++-------------- net/bluetooth/l2cap_sock.c | 4 ++-- 2 files changed, 5 insertions(+), 16 deletions(-) diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index bcbc11c9cb15..a2290ffdc2c1 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -305,7 +305,7 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock) restart: for (sk = bt_accept_get(parent, NULL); sk; sk = next) { - /* Prevent early freeing of sk due to unlink and sock_kill */ + /* The reference from bt_accept_get() keeps sk alive. */ lock_sock(sk); /* Check sk has not already been unlinked via @@ -321,13 +321,11 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock) next = bt_accept_get(parent, sk); - /* sk is safely in the parent list so reduce reference count */ - sock_put(sk); - /* FIXME: Is this check still needed */ if (sk->sk_state == BT_CLOSED) { bt_accept_unlink(sk); release_sock(sk); + sock_put(sk); continue; } @@ -337,16 +335,6 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock) if (newsock) sock_graft(sk, newsock); - /* Hand the caller a reference taken while sk is - * still locked. bt_accept_unlink() just dropped - * the accept-queue reference; without this hold a - * concurrent teardown (e.g. l2cap_conn_del() -> - * l2cap_sock_kill()) could free sk between - * release_sock() and the caller using it. Every - * caller drops this with sock_put() when done. - */ - sock_hold(sk); - release_sock(sk); if (next) sock_put(next); @@ -354,6 +342,7 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock) } release_sock(sk); + sock_put(sk); } return NULL; diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 4853f1b33449..de56ca691afa 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1492,8 +1492,8 @@ static void l2cap_sock_cleanup_listen(struct sock *parent) /* Close not yet accepted channels. * - * bt_accept_dequeue() now returns sk with an extra reference held - * (taken while sk was still locked) so a concurrent l2cap_conn_del() + * bt_accept_dequeue() returns sk with its temporary queue-walk + * reference held, so a concurrent l2cap_conn_del() * -> l2cap_sock_kill() cannot free sk under us. * * cleanup_listen() runs under the parent sk lock, so unlike From 6fef032af0092ed5ccb767239a9ac1bc38c08a40 Mon Sep 17 00:00:00 2001 From: Siwei Zhang Date: Mon, 29 Jun 2026 09:49:58 -0400 Subject: [PATCH 15/20] Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable via the accept queue, so another task can accept and free it before the callback dereferences sk, resulting in a use-after-free. Rework the ->new_connection() op so the core, rather than the callback, owns the child channel's lifetime. The op now receives a pre-allocated new_chan and returns an errno instead of allocating and returning a channel. l2cap_new_connection() allocates the child channel and links it into the conn list via __l2cap_chan_add() before invoking the callback, so the conn-list reference keeps the channel alive once release_sock(parent) exposes the socket to other tasks. Channel configuration that was duplicated in l2cap_sock_init() and the various new_connection callbacks is consolidated into l2cap_chan_set_defaults(), which now inherits from the parent channel when one is supplied. Fixes: 8ffb929098a5 ("Bluetooth: Remove parent socket usage from l2cap_core.c") Cc: stable@kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Siwei Zhang Signed-off-by: Luiz Augusto von Dentz --- include/net/bluetooth/l2cap.h | 10 ++-- net/bluetooth/6lowpan.c | 18 +----- net/bluetooth/l2cap_core.c | 78 ++++++++++++++++++++----- net/bluetooth/l2cap_sock.c | 103 ++++++++++++++++------------------ net/bluetooth/smp.c | 27 ++------- 5 files changed, 127 insertions(+), 109 deletions(-) diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h index 1640cc9bf83a..ef6ce1c20a4f 100644 --- a/include/net/bluetooth/l2cap.h +++ b/include/net/bluetooth/l2cap.h @@ -617,7 +617,8 @@ struct l2cap_chan { struct l2cap_ops { char *name; - struct l2cap_chan *(*new_connection) (struct l2cap_chan *chan); + int (*new_connection)(struct l2cap_chan *chan, + struct l2cap_chan *new_chan); int (*recv) (struct l2cap_chan * chan, struct sk_buff *skb); void (*teardown) (struct l2cap_chan *chan, int err); @@ -882,9 +883,10 @@ static inline __u16 __next_seq(struct l2cap_chan *chan, __u16 seq) return (seq + 1) % (chan->tx_win_max + 1); } -static inline struct l2cap_chan *l2cap_chan_no_new_connection(struct l2cap_chan *chan) +static inline int l2cap_chan_no_new_connection(struct l2cap_chan *chan, + struct l2cap_chan *new_chan) { - return NULL; + return -EOPNOTSUPP; } static inline int l2cap_chan_no_recv(struct l2cap_chan *chan, struct sk_buff *skb) @@ -961,7 +963,7 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len, void l2cap_chan_busy(struct l2cap_chan *chan, int busy); void l2cap_chan_rx_avail(struct l2cap_chan *chan, ssize_t rx_avail); int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator); -void l2cap_chan_set_defaults(struct l2cap_chan *chan); +void l2cap_chan_set_defaults(struct l2cap_chan *chan, struct l2cap_chan *pchan); int l2cap_ertm_init(struct l2cap_chan *chan); void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan); void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan); diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index e7be18a3af33..d504a363a30f 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -632,7 +632,7 @@ static struct l2cap_chan *chan_create(void) if (!chan) return NULL; - l2cap_chan_set_defaults(chan); + l2cap_chan_set_defaults(chan, NULL); chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; chan->mode = L2CAP_MODE_LE_FLOWCTL; @@ -745,21 +745,6 @@ static inline void chan_ready_cb(struct l2cap_chan *chan) ifup(dev->netdev); } -static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) -{ - struct l2cap_chan *chan; - - chan = chan_create(); - if (!chan) - return NULL; - - chan->ops = pchan->ops; - - BT_DBG("chan %p pchan %p", chan, pchan); - - return chan; -} - static void unregister_dev(struct lowpan_btle_dev *dev) { struct hci_dev *hdev = READ_ONCE(dev->hdev); @@ -889,7 +874,6 @@ static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) static const struct l2cap_ops bt_6lowpan_chan_ops = { .name = "L2CAP 6LoWPAN channel", - .new_connection = chan_new_conn_cb, .recv = chan_recv_cb, .close = chan_close_cb, .state_change = chan_state_change_cb, diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 4ee3b9e30c65..519cd9552d86 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -522,7 +522,10 @@ void l2cap_chan_put(struct l2cap_chan *c) } EXPORT_SYMBOL_GPL(l2cap_chan_put); -void l2cap_chan_set_defaults(struct l2cap_chan *chan) +/* Initialise @chan with default values, inheriting from the parent channel + * @pchan when it is given. + */ +void l2cap_chan_set_defaults(struct l2cap_chan *chan, struct l2cap_chan *pchan) { chan->fcs = L2CAP_FCS_CRC16; chan->max_tx = L2CAP_DEFAULT_MAX_TX; @@ -536,6 +539,31 @@ void l2cap_chan_set_defaults(struct l2cap_chan *chan) chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO; chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO; + if (pchan) { + BT_DBG("chan %p pchan %p", chan, pchan); + + chan->chan_type = pchan->chan_type; + chan->imtu = pchan->imtu; + chan->omtu = pchan->omtu; + chan->mode = pchan->mode; + chan->fcs = pchan->fcs; + chan->max_tx = pchan->max_tx; + chan->tx_win = pchan->tx_win; + chan->tx_win_max = pchan->tx_win_max; + chan->sec_level = pchan->sec_level; + chan->conf_state = pchan->conf_state; + chan->flags = pchan->flags; + chan->tx_credits = pchan->tx_credits; + chan->rx_credits = pchan->rx_credits; + + if (chan->chan_type == L2CAP_CHAN_FIXED) { + chan->scid = pchan->scid; + chan->dcid = pchan->scid; + } + + return; + } + chan->conf_state = 0; set_bit(CONF_NOT_COMPLETE, &chan->conf_state); @@ -4024,6 +4052,38 @@ static inline int l2cap_command_rej(struct l2cap_conn *conn, return 0; } +/* Allocate and initialise a channel for an incoming connection. + * + * The channel inherits its configuration from @pchan and is linked into @conn + * before ->new_connection() runs, so the conn list reference keeps it alive if + * the callback exposes it (e.g. via the socket accept queue) before this + * returns. The l2cap_chan_create() reference is taken over by the subsystem on + * success and dropped here on failure. + */ +static struct l2cap_chan *l2cap_new_connection(struct l2cap_conn *conn, + struct l2cap_chan *pchan) +{ + struct l2cap_chan *chan; + + chan = l2cap_chan_create(); + if (!chan) + return NULL; + + l2cap_chan_set_defaults(chan, pchan); + chan->ops = pchan->ops; + + __l2cap_chan_add(conn, chan); + + if (pchan->ops->new_connection && + pchan->ops->new_connection(pchan, chan) < 0) { + l2cap_chan_del(chan, 0); + l2cap_chan_put(chan); + return NULL; + } + + return chan; +} + static void l2cap_connect(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, u8 *data, u8 rsp_code) { @@ -4070,7 +4130,7 @@ static void l2cap_connect(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, goto response; } - chan = pchan->ops->new_connection(pchan); + chan = l2cap_new_connection(conn, pchan); if (!chan) goto response; @@ -4088,8 +4148,6 @@ static void l2cap_connect(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, chan->psm = psm; chan->dcid = scid; - __l2cap_chan_add(conn, chan); - dcid = chan->scid; __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); @@ -4972,7 +5030,7 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn, goto response_unlock; } - chan = pchan->ops->new_connection(pchan); + chan = l2cap_new_connection(conn, pchan); if (!chan) { result = L2CAP_CR_LE_NO_MEM; goto response_unlock; @@ -4987,8 +5045,6 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn, chan->omtu = mtu; chan->remote_mps = mps; - __l2cap_chan_add(conn, chan); - l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits)); dcid = chan->scid; @@ -5196,7 +5252,7 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, continue; } - chan = pchan->ops->new_connection(pchan); + chan = l2cap_new_connection(conn, pchan); if (!chan) { result = L2CAP_CR_LE_NO_MEM; continue; @@ -5211,8 +5267,6 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, chan->omtu = mtu; chan->remote_mps = mps; - __l2cap_chan_add(conn, chan); - l2cap_ecred_init(chan, __le16_to_cpu(req->credits)); /* Init response */ @@ -7492,14 +7546,12 @@ static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status) goto next; l2cap_chan_lock(pchan); - chan = pchan->ops->new_connection(pchan); + chan = l2cap_new_connection(conn, pchan); if (chan) { bacpy(&chan->src, &hcon->src); bacpy(&chan->dst, &hcon->dst); chan->src_type = bdaddr_src_type(hcon); chan->dst_type = dst_type; - - __l2cap_chan_add(conn, chan); } l2cap_chan_unlock(pchan); diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index de56ca691afa..4058ff50cc27 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -43,7 +43,8 @@ static struct bt_sock_list l2cap_sk_list = { static const struct proto_ops l2cap_sock_ops; static void l2cap_sock_init(struct sock *sk, struct sock *parent); static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, - int proto, gfp_t prio, int kern); + int proto, gfp_t prio, int kern, + struct l2cap_chan *chan); static void l2cap_sock_cleanup_listen(struct sock *parent); bool l2cap_is_socket(struct socket *sock) @@ -1284,6 +1285,23 @@ static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg, return err; } +/* Release the sock's ref on chan and clear the pointer so that the ref is + * dropped exactly once even if both l2cap_sock_kill() and + * l2cap_sock_destruct() run. Setting chan->data to NULL first stops any other + * task from dereferencing the now-dead sock pointer. + */ +static void l2cap_sock_put_chan(struct sock *sk) +{ + struct l2cap_chan *chan = l2cap_pi(sk)->chan; + + if (!chan) + return; + + chan->data = NULL; + l2cap_pi(sk)->chan = NULL; + l2cap_chan_put(chan); +} + /* Kill socket (only if zapped and orphan) * Must be called on unlocked socket, with l2cap channel lock. */ @@ -1294,13 +1312,9 @@ static void l2cap_sock_kill(struct sock *sk) BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state)); - /* Sock is dead, so set chan data to NULL, avoid other task use invalid - * sock pointer. - */ - l2cap_pi(sk)->chan->data = NULL; - /* Kill poor orphan */ + l2cap_sock_put_chan(sk); - l2cap_chan_put(l2cap_pi(sk)->chan); + /* Kill poor orphan */ sock_set_flag(sk, SOCK_DEAD); sock_put(sk); } @@ -1543,12 +1557,13 @@ static void l2cap_sock_cleanup_listen(struct sock *parent) } } -static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) +static int l2cap_sock_new_connection_cb(struct l2cap_chan *chan, + struct l2cap_chan *new_chan) { struct sock *sk, *parent = chan->data; if (!parent) - return NULL; + return -EINVAL; lock_sock(parent); @@ -1556,25 +1571,28 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) if (sk_acceptq_is_full(parent)) { BT_DBG("backlog full %d", parent->sk_ack_backlog); release_sock(parent); - return NULL; + return -ENOBUFS; } sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP, - GFP_ATOMIC, 0); + GFP_ATOMIC, 0, new_chan); if (!sk) { release_sock(parent); - return NULL; - } + return -ENOMEM; + } bt_sock_reclassify_lock(sk, BTPROTO_L2CAP); l2cap_sock_init(sk, parent); + /* The conn list reference taken by l2cap_new_connection() keeps new_chan + * alive once release_sock() lets another task free this socket. + */ bt_accept_enqueue(parent, sk, false); release_sock(parent); - return l2cap_pi(sk)->chan; + return 0; } static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) @@ -1871,10 +1889,7 @@ static void l2cap_sock_destruct(struct sock *sk) BT_DBG("sk %p", sk); - if (l2cap_pi(sk)->chan) { - l2cap_pi(sk)->chan->data = NULL; - l2cap_chan_put(l2cap_pi(sk)->chan); - } + l2cap_sock_put_chan(sk); list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) { kfree_skb(rx_busy->skb); @@ -1907,30 +1922,12 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent) BT_DBG("sk %p", sk); if (parent) { - struct l2cap_chan *pchan = l2cap_pi(parent)->chan; - sk->sk_type = parent->sk_type; bt_sk(sk)->flags = bt_sk(parent)->flags; - chan->chan_type = pchan->chan_type; - chan->imtu = pchan->imtu; - chan->omtu = pchan->omtu; - chan->conf_state = pchan->conf_state; - chan->mode = pchan->mode; - chan->fcs = pchan->fcs; - chan->max_tx = pchan->max_tx; - chan->tx_win = pchan->tx_win; - chan->tx_win_max = pchan->tx_win_max; - chan->sec_level = pchan->sec_level; - chan->flags = pchan->flags; - chan->tx_credits = pchan->tx_credits; - chan->rx_credits = pchan->rx_credits; - - if (chan->chan_type == L2CAP_CHAN_FIXED) { - chan->scid = pchan->scid; - chan->dcid = pchan->scid; - } - + /* Channel configuration is inherited from the parent by + * l2cap_new_connection(). + */ security_sk_clone(parent, sk); } else { switch (sk->sk_type) { @@ -1956,7 +1953,7 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent) chan->mode = L2CAP_MODE_BASIC; } - l2cap_chan_set_defaults(chan); + l2cap_chan_set_defaults(chan, NULL); } /* Default config options */ @@ -1975,10 +1972,10 @@ static struct proto l2cap_proto = { }; static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, - int proto, gfp_t prio, int kern) + int proto, gfp_t prio, int kern, + struct l2cap_chan *chan) { struct sock *sk; - struct l2cap_chan *chan; sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern); if (!sk) @@ -1989,16 +1986,7 @@ static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy); - chan = l2cap_chan_create(); - if (!chan) { - sk_free(sk); - if (sock) - sock->sk = NULL; - return NULL; - } - - l2cap_chan_hold(chan); - + /* The sock takes ownership of the caller's reference on chan. */ l2cap_pi(sk)->chan = chan; return sk; @@ -2008,6 +1996,7 @@ static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol, int kern) { struct sock *sk; + struct l2cap_chan *chan; BT_DBG("sock %p", sock); @@ -2022,10 +2011,16 @@ static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol, sock->ops = &l2cap_sock_ops; - sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern); - if (!sk) + chan = l2cap_chan_create(); + if (!chan) return -ENOMEM; + sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern, chan); + if (!sk) { + l2cap_chan_put(chan); + return -ENOMEM; + } + l2cap_sock_init(sk, NULL); bt_sock_link(&l2cap_sk_list, sk); return 0; diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 031d3022cb1e..c4470958b0d5 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -3201,34 +3201,19 @@ static const struct l2cap_ops smp_chan_ops = { .get_sndtimeo = l2cap_chan_no_get_sndtimeo, }; -static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) +static inline int smp_new_conn_cb(struct l2cap_chan *chan, + struct l2cap_chan *new_chan) { - struct l2cap_chan *chan; - - BT_DBG("pchan %p", pchan); - - chan = l2cap_chan_create(); - if (!chan) - return NULL; - - chan->chan_type = pchan->chan_type; - chan->ops = &smp_chan_ops; - chan->scid = pchan->scid; - chan->dcid = chan->scid; - chan->imtu = pchan->imtu; - chan->omtu = pchan->omtu; - chan->mode = pchan->mode; + new_chan->ops = &smp_chan_ops; /* Other L2CAP channels may request SMP routines in order to * change the security level. This means that the SMP channel * lock must be considered in its own category to avoid lockdep * warnings. */ - atomic_set(&chan->nesting, L2CAP_NESTING_SMP); + atomic_set(&new_chan->nesting, L2CAP_NESTING_SMP); - BT_DBG("created chan %p", chan); - - return chan; + return 0; } static const struct l2cap_ops smp_root_chan_ops = { @@ -3288,7 +3273,7 @@ static struct l2cap_chan *smp_add_cid(struct hci_dev *hdev, u16 cid) l2cap_add_scid(chan, cid); - l2cap_chan_set_defaults(chan); + l2cap_chan_set_defaults(chan, NULL); if (cid == L2CAP_CID_SMP) { u8 bdaddr_type; From 9c36951474d8e1127f4946f39cb874a200f34e9f Mon Sep 17 00:00:00 2001 From: Kiran K Date: Tue, 30 Jun 2026 22:29:19 +0530 Subject: [PATCH 16/20] Bluetooth: btintel_pcie: Refactor FLR to use device_reprobe() The FLR branch in btintel_pcie_reset_work() open-coded the entire re-init sequence: btintel_pcie_release_hdev() (hci_unregister_dev + hci_free_dev), pci_try_reset_function(), enable_interrupts / config_msix / enable_bt / reset_ia / start_rx, then btintel_pcie_setup_hdev() (hci_alloc_dev_priv + hci_register_dev). Every probe() init step had to be kept in sync with this second copy in the reset path, and any failure mid-sequence left state to unwind by hand. The PLDR path already delegates teardown and re-init to the PCI core via device_reprobe(): .remove() destroys data through devres and unregisters hdev, then .probe() rebuilds everything from scratch. Apply the same model to FLR. Introduce btintel_pcie_perform_flr() mirroring perform_pldr(). It runs pci_try_reset_function() (required to avoid the device_lock ABBA against btintel_pcie_remove(), which calls disable_work_sync(&reset_work) while holding device_lock) followed by device_reprobe(). On success, data is destroyed and a fresh probe re-INIT_WORKs coredump_work with disable count 0, so enable_work() must not be called; on failure, data is still alive and the caller balances the earlier disable_work_sync(). The contract is documented on the helper and reiterated at the reset_work() call site. reset_work() shrinks to interrupt/worker drain, dispatch on reset_type, and the single asymmetry between the two paths. The out_enable label, the manual unregister/register pair, and the forward declaration of btintel_pcie_setup_hdev() are dropped. No intended functional change; FLR and PLDR now share one teardown contract. Fixes: 256ab9520d15 ("Bluetooth: btintel_pcie: Support Function level reset") Assisted-by: GitHub-Copilot:claude-4.7-opus Signed-off-by: Kiran K Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/btintel_pcie.c | 102 ++++++++++++++++--------------- 1 file changed, 52 insertions(+), 50 deletions(-) diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c index 9e39327dc1fe..2b7231be5973 100644 --- a/drivers/bluetooth/btintel_pcie.c +++ b/drivers/bluetooth/btintel_pcie.c @@ -2127,6 +2127,9 @@ static int btintel_pcie_send_frame(struct hci_dev *hdev, if (test_bit(BTINTEL_PCIE_CORE_HALTED, &data->flags)) return -ENODEV; + if (test_bit(BTINTEL_PCIE_RECOVERY_IN_PROGRESS, &data->flags)) + return -ENODEV; + /* Due to the fw limitation, the type header of the packet should be * 4 bytes unlike 1 byte for UART. In UART, the firmware can read * the first byte to get the packet type and redirect the rest of data @@ -2485,7 +2488,6 @@ static void btintel_pcie_inc_recovery_count(struct pci_dev *pdev, } } -static int btintel_pcie_setup_hdev(struct btintel_pcie_data *data); static void btintel_pcie_reset(struct hci_dev *hdev); static int btintel_pcie_acpi_reset_method(struct btintel_pcie_data *data) @@ -2596,12 +2598,45 @@ static void btintel_pcie_perform_pldr(struct btintel_pcie_data *data) } } +/* + * Issue a Function Level Reset and hand teardown/re-init off to the PCI + * core via device_reprobe(), mirroring the PLDR path's contract. + * + * Caller must hold pci_lock_rescan_remove() and must have already + * disabled interrupts and drained both rx_work and coredump_work. + */ +static int btintel_pcie_perform_flr(struct btintel_pcie_data *data) +{ + struct pci_dev *pdev = data->pdev; + int err; + + /* pci_try_reset_function() avoids the device_lock ABBA against + * btintel_pcie_remove(): .remove() runs with device_lock held and + * then waits for this work via disable_work_sync(); the blocking + * pci_reset_function() would deadlock by trying to re-acquire + * device_lock here. + */ + err = pci_try_reset_function(pdev); + if (err) { + BT_ERR("Failed resetting the pcie device (%d)", err); + return err; + } + + /* device_reprobe() always detaches the driver first (running + * .remove(), which frees 'data'); any re-probe failure leaves the + * device unbound but 'data' is already gone, so just log it. + */ + if (device_reprobe(&pdev->dev)) + BT_ERR("BT reprobe failed for BDF:%s", pci_name(pdev)); + + return 0; +} + static void btintel_pcie_reset_work(struct work_struct *wk) { struct btintel_pcie_data *data = container_of(wk, struct btintel_pcie_data, reset_work); struct pci_dev *pdev = data->pdev; - int err; pci_lock_rescan_remove(); @@ -2621,60 +2656,27 @@ static void btintel_pcie_reset_work(struct work_struct *wk) disable_work_sync(&data->coredump_work); bt_dev_dbg(data->hdev, "Release bluetooth interface"); + + /* Both reset paths follow the same contract: on success they + * destroy 'data' via device_reprobe() (a fresh probe re-INIT_WORKs + * the coredump_work with disable count 0), so enable_work() must + * NOT be called on the success path. Only the FLR path can fail + * with 'data' still alive, in which case we balance the + * disable_work_sync() above so a later successful reset is not + * permanently blocked. + * + * pci_lock_rescan_remove() (held above) serializes against PCI + * device addition/removal (hotplug), so no device can be added to + * or removed from the bus list while this code runs. + */ if (data->reset_type == BTINTEL_PCIE_IOSF_PRR_PLDR) { - /* This function holds pci_lock_rescan_remove(), which acquires - * pci_rescan_remove_lock. This mutex serializes against PCI device - * addition/removal (hotplug), so no device can be added to or - * removed from the bus list while this code runs. - * - * device_reprobe() inside btintel_pcie_perform_pldr() destroys - * 'data' via .remove(); a fresh probe re-INIT_WORKs the - * coredump_work with disable count 0, so we must not call - * enable_work() on this path. - */ btintel_pcie_perform_pldr(data); goto out; } - btintel_pcie_release_hdev(data); - /* Use pci_try_reset_function() rather than pci_reset_function() to - * avoid an ABBA deadlock against btintel_pcie_remove(): the PCI core - * calls .remove() with device_lock held, and remove() then waits for - * this work via cancel_work_sync(); pci_reset_function() would in - * turn try to acquire the same device_lock, deadlocking both paths. - */ - err = pci_try_reset_function(pdev); - if (err) { - BT_ERR("Failed resetting the pcie device (%d)", err); - goto out_enable; - } + if (btintel_pcie_perform_flr(data)) + enable_work(&data->coredump_work); - btintel_pcie_enable_interrupts(data); - btintel_pcie_config_msix(data); - - err = btintel_pcie_enable_bt(data); - if (err) { - BT_ERR("Failed to enable bluetooth hardware after reset (%d)", - err); - goto out_enable; - } - - btintel_pcie_reset_ia(data); - btintel_pcie_start_rx(data); - data->flags = 0; - - err = btintel_pcie_setup_hdev(data); - if (err) { - BT_ERR("Failed registering hdev (%d)", err); - goto out_enable; - } - -out_enable: - /* Balance disable_work_sync() above on every exit. Leaving the - * counter incremented on a failed reset would permanently disable - * coredump_work even after a later successful reset. - */ - enable_work(&data->coredump_work); out: pci_dev_put(pdev); pci_unlock_rescan_remove(); From e054c1a6ae7310d2815778fddb87da616e11c255 Mon Sep 17 00:00:00 2001 From: Pauli Virtanen Date: Wed, 1 Jul 2026 18:46:38 +0300 Subject: [PATCH 17/20] Bluetooth: ISO: fix malformed ISO_END/CONT handling Core specification (Part C vol 4 sec 5.4.5) does not exclude empty ISO_CONT, ISO_END packets. We currently reject them if they are last. If controller sends malformed sequence ISO_START -> rx_len = 4, ISO_CONT skb->len 4, ISO_START that ends payload in ISO_CONT, we leak conn->rx_skb. If controller sends too long ISO_END, we panic on skb_put. If controller sends too short ISO_END we accept it. Fix by marking unfinished ISO_START via conn->rx_skb != NULL. Check skb->len properly before skb_put. Combine the ISO_CONT/END code paths as they require the same initial checks. Reject too short ISO_END packets. Fixes: 84c24fb151fc ("Bluetooth: ISO: drop ISO_END frames received without prior ISO_START") Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/iso.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index cd7c7c9ea4fc..2e95a153912c 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -2540,7 +2540,7 @@ int iso_recv(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, u16 flags) switch (pb) { case ISO_START: case ISO_SINGLE: - if (conn->rx_len) { + if (conn->rx_skb || conn->rx_len) { BT_ERR("Unexpected start frame (len %d)", skb->len); kfree_skb(conn->rx_skb); conn->rx_skb = NULL; @@ -2621,12 +2621,14 @@ int iso_recv(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, u16 flags) break; case ISO_CONT: - BT_DBG("Cont: frag len %d (expecting %d)", skb->len, + case ISO_END: + BT_DBG("%s: frag len %d (expecting %d)", + (pb == ISO_END) ? "End" : "Cont", skb->len, conn->rx_len); - if (!conn->rx_len) { - BT_ERR("Unexpected continuation frame (len %d)", - skb->len); + if (!conn->rx_skb) { + BT_ERR("Unexpected ISO %s frame (len %d)", + (pb == ISO_END) ? "End" : "Cont", skb->len); goto drop; } @@ -2642,17 +2644,9 @@ int iso_recv(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, u16 flags) skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len), skb->len); conn->rx_len -= skb->len; - break; - case ISO_END: - if (!conn->rx_len) { - BT_ERR("Unexpected end frame (len %d)", skb->len); - goto drop; - } - - skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len), - skb->len); - conn->rx_len -= skb->len; + if (pb == ISO_CONT) + break; if (!conn->rx_len) { struct sk_buff *rx_skb = conn->rx_skb; @@ -2663,6 +2657,13 @@ int iso_recv(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, u16 flags) */ conn->rx_skb = NULL; iso_recv_frame(conn, rx_skb); + } else { + BT_ERR("ISO fragment incomplete (len %d, expected %d)", + skb->len, conn->rx_len); + kfree_skb(conn->rx_skb); + conn->rx_skb = NULL; + conn->rx_len = 0; + goto drop; } break; } From fd076d8deeab6f9f18ef13400f89e1f550df665b Mon Sep 17 00:00:00 2001 From: Pauli Virtanen Date: Wed, 1 Jul 2026 18:46:39 +0300 Subject: [PATCH 18/20] Bluetooth: ISO: exclude RFU bits from ISO_SDU_Length slen contains ISO_SDU_Length (12 bits), RFU (2 bits), Packet_Status_Flags (2 bits). Exclude the RFU bits from hci_iso_data_len. Also add masks to the pack macro. Fixes: 4de0fc599eb9 ("Bluetooth: Add definitions for CIS connections") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz --- include/net/bluetooth/hci.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h index 38186a245f14..50f0eef71fb1 100644 --- a/include/net/bluetooth/hci.h +++ b/include/net/bluetooth/hci.h @@ -3413,8 +3413,9 @@ static inline struct hci_iso_hdr *hci_iso_hdr(const struct sk_buff *skb) #define hci_iso_flags_pack(pb, ts) ((pb & 0x03) | ((ts & 0x01) << 2)) /* ISO data length and flags pack/unpack */ -#define hci_iso_data_len_pack(h, f) ((__u16) ((h) | ((f) << 14))) -#define hci_iso_data_len(h) ((h) & 0x3fff) +#define hci_iso_data_len_pack(h, f) ((__u16) (((h) & 0x0fff) | \ + (((f) & 0x3) << 14))) +#define hci_iso_data_len(h) ((h) & 0x0fff) #define hci_iso_data_flags(h) ((h) >> 14) /* codec transport types */ From dd068ef044128db655f48323a4acfd5907e04903 Mon Sep 17 00:00:00 2001 From: Weiming Shi Date: Wed, 1 Jul 2026 09:06:14 -0700 Subject: [PATCH 19/20] Bluetooth: bpa10x: avoid OOB read of revision string in bpa10x_setup() bpa10x_setup() sends the vendor command 0xfc0e and passes the response to bt_dev_info() and hci_set_fw_info() as a "%s" string starting at skb->data + 1, without checking the length: bt_dev_info(hdev, "%s", (char *)(skb->data + 1)); hci_set_fw_info(hdev, "%s", skb->data + 1); A device that returns a one-byte response (status only) leaves skb->data + 1 past the end of the data, and the %s walk reads adjacent slab memory until it meets a NUL. The same happens when the payload is not NUL-terminated within skb->len. The out-of-bounds bytes end up in the kernel log and the firmware-info debugfs file. Print the revision string with a bounded "%.*s" limited to skb->len - 1 instead. This keeps the string readable for well-behaved devices while never reading past the received data, and does not fail setup, so a device returning a short or unterminated response keeps working. Fixes: ddd68ec8f484 ("Bluetooth: bpa10x: Read revision information in setup stage") Reported-by: Xiang Mei Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Weiming Shi Reported-by: Xiang Mei Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/bpa10x.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/bluetooth/bpa10x.c b/drivers/bluetooth/bpa10x.c index 2ae38a321c4b..e63d1af250ec 100644 --- a/drivers/bluetooth/bpa10x.c +++ b/drivers/bluetooth/bpa10x.c @@ -255,9 +255,13 @@ static int bpa10x_setup(struct hci_dev *hdev) if (IS_ERR(skb)) return PTR_ERR(skb); - bt_dev_info(hdev, "%s", (char *)(skb->data + 1)); + /* Bounded print: the device controls skb->len. */ + if (skb->len > 1) { + int len = skb->len - 1; - hci_set_fw_info(hdev, "%s", skb->data + 1); + bt_dev_info(hdev, "%.*s", len, (char *)(skb->data + 1)); + hci_set_fw_info(hdev, "%.*s", len, skb->data + 1); + } kfree_skb(skb); return 0; From 6e1930ece855a4c256f1c7e6632d634cfb9888b5 Mon Sep 17 00:00:00 2001 From: Stig Hornang Date: Fri, 12 Jun 2026 16:38:18 +0200 Subject: [PATCH 20/20] Bluetooth: L2CAP: fix tx ident leak for commands without a response Commit 6c3ea155e5ee ("Bluetooth: L2CAP: Fix not tracking outstanding TX ident") changed ident allocation to use an IDA, releasing idents in l2cap_put_ident() when the matching response command is received. But identifiers allocated for commands that have no response defined are never released. In particular L2CAP_LE_CREDITS is sent repeatedly for the lifetime of an LE CoC channel, so a peer streaming data to the host exhausts the 1-255 ident range after 254 credit packets. From then on l2cap_get_ident() fails: kernel: Bluetooth: Unable to allocate ident: -28 and every subsequent L2CAP_LE_CREDITS packet is sent with ident 0, which is invalid (Core Spec, Vol 3, Part A, Section 4: "Signaling identifier 0x00 is an invalid identifier and shall never be used in any command"). Remote stacks that validate the ident drop these commands, never receive new credits, and the channel stalls permanently. With default socket buffers this happens after roughly 0.5 MB of received data (the exact amount depends on the socket receive buffer): < ACL Data TX: Handle 2048 flags 0x00 dlen 12 LE L2CAP: LE Flow Control Credit (0x16) ident 0 len 4 Source CID: 64 Credits: 1 Release the ident immediately after sending L2CAP_LE_CREDITS since no response will ever release it. Use a local variable instead of chan->ident so that an ident that an EXT_FLOWCTL channel may be waiting on (e.g. a pending reconfigure) is not overwritten by a credit packet. Also add the missing L2CAP_LE_CONN_RSP case to l2cap_put_ident() so idents allocated for outgoing L2CAP_LE_CONN_REQ commands are released when the response arrives. Fixes: 6c3ea155e5ee ("Bluetooth: L2CAP: Fix not tracking outstanding TX ident") Link: https://bugzilla.kernel.org/show_bug.cgi?id=221629 Assisted-by: Claude:claude-opus-4.8 Assisted-by: Fable:5 Signed-off-by: Stig Hornang Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/l2cap_core.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 519cd9552d86..538ae9aa3479 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4879,6 +4879,7 @@ static void l2cap_put_ident(struct l2cap_conn *conn, u8 code, u8 id) case L2CAP_ECHO_RSP: case L2CAP_INFO_RSP: case L2CAP_CONN_PARAM_UPDATE_RSP: + case L2CAP_LE_CONN_RSP: case L2CAP_ECRED_CONN_RSP: case L2CAP_ECRED_RECONF_RSP: /* First do a lookup since the remote may send bogus ids that @@ -6772,6 +6773,7 @@ static void l2cap_chan_le_send_credits(struct l2cap_chan *chan) struct l2cap_conn *conn = chan->conn; struct l2cap_le_credits pkt; u16 return_credits = l2cap_le_rx_credits(chan); + int ident; if (chan->mode != L2CAP_MODE_LE_FLOWCTL && chan->mode != L2CAP_MODE_EXT_FLOWCTL) @@ -6789,9 +6791,18 @@ static void l2cap_chan_le_send_credits(struct l2cap_chan *chan) pkt.cid = cpu_to_le16(chan->scid); pkt.credits = cpu_to_le16(return_credits); - chan->ident = l2cap_get_ident(conn); + ident = l2cap_get_ident(conn); - l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt); + l2cap_send_cmd(conn, ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt); + + /* L2CAP_LE_CREDITS has no response so the ident is never released by + * l2cap_put_ident() - release it right away, otherwise the tx_ida + * range is exhausted after 254 packets and from then on credits are + * sent with the invalid ident 0, which some remote stacks ignore, + * stalling the channel. + */ + if (ident > 0) + ida_free(&conn->tx_ida, ident); } void l2cap_chan_rx_avail(struct l2cap_chan *chan, ssize_t rx_avail)