linux/net/bluetooth
Chengfeng Ye 848a7a91c7 Bluetooth: hci_core: Serialize SCO and ISO scheduling with teardown
hci_low_sent() selects a connection under RCU but drops the read lock
before calculating its quota and returning it to the scheduler. The
connection is then used without lifetime protection by hci_sched_iso()
and hci_sched_sco().

After the TX worker drops the RCU read lock, hci_abort_conn_sync() on
hdev->req_workqueue can remove the connection from the hash, complete
synchronize_rcu(), purge its queues and release it. The TX worker on
hdev->workqueue can then access the freed connection in hci_quote_sent()
or while dequeuing packets and updating conn->sent.

KASAN reported:

  BUG: KASAN: slab-use-after-free in hci_low_sent+0x730/0x840
  Workqueue: hci0 hci_tx_work
  Call Trace:
   hci_low_sent+0x730/0x840
   hci_sched_iso+0x25e/0x4d0
   hci_tx_work+0x239/0xcb0

  Allocated by task 93:
   __hci_conn_add+0x16f/0x1b40
   hci_bind_bis+0x782/0x17b0
   hci_connect_bis+0xa0/0x510
   iso_sock_connect+0x589/0x1050

  Freed by task 88:
   kfree+0x131/0x3c0
   device_release+0xc8/0x240
   kobject_put+0x14d/0x280
   hci_conn_del+0x55a/0xe80
   hci_disconnect_sync+0x156/0x180
   hci_abort_conn_sync+0x3e7/0x940
   hci_cmd_sync_work+0x13c/0x290

Hold hci_dev_lock() across connection selection and transmission in both
SCO and ISO scheduling, serializing them with connection teardown. This
also prevents queuing completion timestamps after the connection queues
have been purged. Extending RCU across transmission would be unsafe
because the transmit path can sleep. Keep the ISO timeout check outside
the mutex since hci_link_tx_to() takes it itself.

The preceding channel fix already holds this mutex in the ACL and LE
schedulers, which call the SCO scheduler between packets. Move the SCO
body to __hci_sched_sco(), assert that its caller holds the mutex, and
use it directly from these locked paths. Keep a locking hci_sched_sco()
wrapper for the direct calls from hci_tx_work(). This avoids recursively
acquiring the device mutex while preserving the scheduling order.

Remove the obsolete claim that connection removal disables TX.

Fixes: bf4c632524 ("Bluetooth: convert conn hash to RCU")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-09-28 11:00:20 -04:00
..
bnep Bluetooth: bnep: fix out-of-bounds reads on short RX/TX frames and control fallthrough 2026-09-21 09:37:19 -04:00
hidp Bluetooth: fix BT dependency for submodules 2026-08-07 15:38:30 -04:00
rfcomm Bluetooth: RFCOMM: Fix initial port reference race 2026-09-28 11:00:20 -04:00
6lowpan.c Bluetooth: add annotations for l2cap_data locking context 2026-08-07 15:38:32 -04:00
af_bluetooth.c Bluetooth: af_bluetooth: Add minimal context analysis annotations 2026-08-07 12:26:02 -04:00
aosp.c Bluetooth: aosp: Fix typo in comment 2025-07-23 10:30:18 -04:00
aosp.h Bluetooth: aosp: Support AOSP Bluetooth Quality Report 2021-11-02 19:37:52 +01:00
coredump.c Bluetooth: coredump: Quiesce dump work on unregister 2026-09-15 14:49:41 -04:00
ecdh_helper.c Bluetooth: Add SPDX id lines to some source files 2026-06-11 14:24:41 -04:00
ecdh_helper.h Bluetooth: Add SPDX id lines to some source files 2026-06-11 14:24:41 -04:00
eir.c Bluetooth: eir: validate service data length before reading UUID 2026-09-15 14:30:14 -04:00
eir.h Bluetooth: eir: Fix possible crashes on eir_create_adv_data 2025-06-11 16:29:22 -04:00
hci_codec.c Bluetooth: hci_codec: validate vendor codec count length 2026-09-15 14:52:12 -04:00
hci_codec.h Bluetooth: Add support for Read Local Supported Codecs V2 2021-09-07 14:09:18 -07:00
hci_conn.c Bluetooth: hci_conn: Lock parent access during enhanced SCO setup 2026-09-28 11:00:20 -04:00
hci_core.c Bluetooth: hci_core: Serialize SCO and ISO scheduling with teardown 2026-09-28 11:00:20 -04:00
hci_debugfs.c Bluetooth: hci_core: Fix inquiry cache timestamps on 64-bit systems 2026-09-23 09:30:21 -04:00
hci_debugfs.h Bluetooth: Add SPDX id lines to some source files 2026-06-11 14:24:41 -04:00
hci_drv.c Bluetooth: Introduce HCI Driver protocol 2025-05-21 10:28:07 -04:00
hci_event.c Bluetooth: hci_event: clear HCI_LE_ADV only on a created connection 2026-08-24 13:11:42 -04:00
hci_sock.c Bluetooth: hci_sock: validate event length before filtering 2026-09-16 13:51:34 -04:00
hci_sync.c Bluetooth: hci_sync: Fix inquiry cache use-after-free 2026-09-28 11:00:20 -04:00
hci_sysfs.c Bluetooth: hci_sysfs: Fix NULL pointer dereference in device_del() 2026-09-08 17:12:45 -04:00
iso.c Bluetooth: ISO: release unused CIS holds after channel attach 2026-09-16 13:51:34 -04:00
Kconfig Bluetooth: fix BT dependency for submodules 2026-08-07 15:38:30 -04:00
l2cap_core.c Bluetooth: L2CAP: validate frame length before control and FCS access 2026-09-16 13:51:34 -04:00
l2cap_sock.c Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan 2026-08-24 13:06:49 -04:00
leds.c Bluetooth: Use led_set_brightness() in LED trigger activate() callback 2024-09-10 13:06:11 -04:00
leds.h
lib.c Bluetooth: Add SPDX id lines to some source files 2026-06-11 14:24:41 -04:00
Makefile Bluetooth: enable context analysis 2026-08-07 12:27:20 -04:00
mgmt_config.c Bluetooth: mgmt: Add idle_timeout to configurable system parameters 2026-01-29 13:24:22 -05:00
mgmt_config.h
mgmt_util.c Bluetooth: Add SPDX id lines to some source files 2026-06-11 14:24:41 -04:00
mgmt_util.h Bluetooth: Add SPDX id lines to some source files 2026-06-11 14:24:41 -04:00
mgmt.c Bluetooth: mgmt: fix race in read_unconf_index_list() 2026-09-16 13:51:34 -04:00
msft.c Bluetooth: hci_core: Fix race condition during device registration 2026-08-31 13:52:54 -04:00
msft.h Bluetooth: msft: fix slab-use-after-free in msft_do_close() 2024-05-03 13:05:28 -04:00
sco.c Bluetooth: SCO: give the socket its own sco_conn reference 2026-07-28 16:13:48 -04:00
selftest.c Bluetooth: Add SPDX id lines to some source files 2026-06-11 14:24:41 -04:00
selftest.h Bluetooth: Add SPDX id lines to some source files 2026-06-11 14:24:41 -04:00
smp.c Bluetooth: Serialize SMP remote OOB data access 2026-09-28 11:00:20 -04:00
smp.h Bluetooth: add annotations for l2cap_data locking context 2026-08-07 15:38:32 -04:00