From cadf6019231b614ebbd9ec2a16e5997ecbd8d016 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Tue, 10 Mar 2026 13:48:03 +0100 Subject: [PATCH 1/5] can: netlink: can_changelink(): add missing error handling to call can_ctrlmode_changelink() In commit e1a5cd9d6665 ("can: netlink: add can_ctrlmode_changelink()") the CAN Control Mode (IFLA_CAN_CTRLMODE) handling was factored out into the can_ctrlmode_changelink() function. But the call to can_ctrlmode_changelink() is missing the error handling. Add the missing error handling and propagation to the call can_ctrlmode_changelink(). Cc: stable@vger.kernel.org Fixes: e1a5cd9d6665 ("can: netlink: add can_ctrlmode_changelink()") Link: https://patch.msgid.link/20260310-can_ctrlmode_changelink-add-error-handling-v1-1-0daf63d85922@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/netlink.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 0498198a4696..766d455950f5 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -601,7 +601,9 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[], /* We need synchronization with dev->stop() */ ASSERT_RTNL(); - can_ctrlmode_changelink(dev, data, extack); + err = can_ctrlmode_changelink(dev, data, extack); + if (err) + return err; if (data[IFLA_CAN_BITTIMING]) { struct can_bittiming bt; From 7a57354756c7df223abe2c33774235ad70cb4231 Mon Sep 17 00:00:00 2001 From: Wenyuan Li <2063309626@qq.com> Date: Mon, 16 Mar 2026 00:00:22 +0800 Subject: [PATCH 2/5] can: mcp251x: add error handling for power enable in open and resume Add missing error handling for mcp251x_power_enable() calls in both mcp251x_open() and mcp251x_can_resume() functions. In mcp251x_open(), if power enable fails, jump to error path to close candev without attempting to disable power again. In mcp251x_can_resume(), properly check return values of power enable calls for both power and transceiver regulators. If any fails, return the error code to the PM framework and log the failure. This ensures the driver properly handles power control failures and maintains correct device state. Signed-off-by: Wenyuan Li <2063309626@qq.com> Link: https://patch.msgid.link/tencent_F3EFC5D7738AC548857B91657715E2D3AA06@qq.com [mkl: fix patch description] [mkl: mcp251x_can_resume(): replace goto by return] Signed-off-by: Marc Kleine-Budde --- drivers/net/can/spi/mcp251x.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index bb7782582f40..0d0190ae094a 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -1225,7 +1225,11 @@ static int mcp251x_open(struct net_device *net) } mutex_lock(&priv->mcp_lock); - mcp251x_power_enable(priv->transceiver, 1); + ret = mcp251x_power_enable(priv->transceiver, 1); + if (ret) { + dev_err(&spi->dev, "failed to enable transceiver power: %pe\n", ERR_PTR(ret)); + goto out_close_candev; + } priv->force_quit = 0; priv->tx_skb = NULL; @@ -1272,6 +1276,7 @@ static int mcp251x_open(struct net_device *net) mcp251x_hw_sleep(spi); out_close: mcp251x_power_enable(priv->transceiver, 0); +out_close_candev: close_candev(net); mutex_unlock(&priv->mcp_lock); if (release_irq) @@ -1516,11 +1521,25 @@ static int __maybe_unused mcp251x_can_resume(struct device *dev) { struct spi_device *spi = to_spi_device(dev); struct mcp251x_priv *priv = spi_get_drvdata(spi); + int ret = 0; - if (priv->after_suspend & AFTER_SUSPEND_POWER) - mcp251x_power_enable(priv->power, 1); - if (priv->after_suspend & AFTER_SUSPEND_UP) - mcp251x_power_enable(priv->transceiver, 1); + if (priv->after_suspend & AFTER_SUSPEND_POWER) { + ret = mcp251x_power_enable(priv->power, 1); + if (ret) { + dev_err(dev, "failed to restore power: %pe\n", ERR_PTR(ret)); + return ret; + } + } + + if (priv->after_suspend & AFTER_SUSPEND_UP) { + ret = mcp251x_power_enable(priv->transceiver, 1); + if (ret) { + dev_err(dev, "failed to restore transceiver power: %pe\n", ERR_PTR(ret)); + if (priv->after_suspend & AFTER_SUSPEND_POWER) + mcp251x_power_enable(priv->power, 0); + return ret; + } + } if (priv->after_suspend & (AFTER_SUSPEND_POWER | AFTER_SUSPEND_UP)) queue_work(priv->wq, &priv->restart_work); From 46eee1661aa9b49966e6c43d07126fe408edda57 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Wed, 18 Mar 2026 18:34:13 +0100 Subject: [PATCH 3/5] can: statistics: add missing atomic access in hot path Commit 80b5f90158d1 ("can: statistics: use atomic access in hot path") fixed a KCSAN issue in can_receive() but missed to convert the 'matches' variable used in can_rcv_filter(). Fixes: 80b5f90158d1 ("can: statistics: use atomic access in hot path") Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260318173413.28235-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde --- net/can/af_can.c | 4 ++-- net/can/af_can.h | 2 +- net/can/proc.c | 3 ++- 3 files changed, 5 insertions(+), 4 deletions(-) diff --git a/net/can/af_can.c b/net/can/af_can.c index f70e2ba0aadc..7bc86b176b4d 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -469,7 +469,7 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id, rcv->can_id = can_id; rcv->mask = mask; - rcv->matches = 0; + atomic_long_set(&rcv->matches, 0); rcv->func = func; rcv->data = data; rcv->ident = ident; @@ -573,7 +573,7 @@ EXPORT_SYMBOL(can_rx_unregister); static inline void deliver(struct sk_buff *skb, struct receiver *rcv) { rcv->func(skb, rcv->data); - rcv->matches++; + atomic_long_inc(&rcv->matches); } static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb) diff --git a/net/can/af_can.h b/net/can/af_can.h index 22f3352c77fe..87887014f562 100644 --- a/net/can/af_can.h +++ b/net/can/af_can.h @@ -52,7 +52,7 @@ struct receiver { struct hlist_node list; canid_t can_id; canid_t mask; - unsigned long matches; + atomic_long_t matches; void (*func)(struct sk_buff *skb, void *data); void *data; char *ident; diff --git a/net/can/proc.c b/net/can/proc.c index 0938bf7dd646..de4d05ae3459 100644 --- a/net/can/proc.c +++ b/net/can/proc.c @@ -196,7 +196,8 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list, " %-5s %03x %08x %pK %pK %8ld %s\n"; seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask, - r->func, r->data, r->matches, r->ident); + r->func, r->data, atomic_long_read(&r->matches), + r->ident); } } From b9c310d72783cc2f30d103eed83920a5a29c671a Mon Sep 17 00:00:00 2001 From: Ali Norouzi Date: Thu, 19 Mar 2026 16:47:44 +0100 Subject: [PATCH 4/5] can: gw: fix OOB heap access in cgw_csum_crc8_rel() cgw_csum_crc8_rel() correctly computes bounds-safe indices via calc_idx(): int from = calc_idx(crc8->from_idx, cf->len); int to = calc_idx(crc8->to_idx, cf->len); int res = calc_idx(crc8->result_idx, cf->len); if (from < 0 || to < 0 || res < 0) return; However, the loop and the result write then use the raw s8 fields directly instead of the computed variables: for (i = crc8->from_idx; ...) /* BUG: raw negative index */ cf->data[crc8->result_idx] = ...; /* BUG: raw negative index */ With from_idx = to_idx = result_idx = -64 on a 64-byte CAN FD frame, calc_idx(-64, 64) = 0 so the guard passes, but the loop iterates with i = -64, reading cf->data[-64], and the write goes to cf->data[-64]. This write might end up to 56 (7.0-rc) or 40 (<= 6.19) bytes before the start of the canfd_frame on the heap. The companion function cgw_csum_xor_rel() uses `from`/`to`/`res` correctly throughout; fix cgw_csum_crc8_rel() to match. Confirmed with KASAN on linux-7.0-rc2: BUG: KASAN: slab-out-of-bounds in cgw_csum_crc8_rel+0x515/0x5b0 Read of size 1 at addr ffff8880076619c8 by task poc_cgw_oob/62 To configure the can-gw crc8 checksums CAP_NET_ADMIN is needed. Fixes: 456a8a646b25 ("can: gw: add support for CAN FD frames") Cc: stable@vger.kernel.org Reported-by: Ali Norouzi Reviewed-by: Oliver Hartkopp Acked-by: Oliver Hartkopp Signed-off-by: Ali Norouzi Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260319-fix-can-gw-and-can-isotp-v2-1-c45d52c6d2d8@pengutronix.de Signed-off-by: Marc Kleine-Budde --- net/can/gw.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/can/gw.c b/net/can/gw.c index 8ee4d67a07d3..0ec99f68aa45 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -375,10 +375,10 @@ static void cgw_csum_crc8_rel(struct canfd_frame *cf, return; if (from <= to) { - for (i = crc8->from_idx; i <= crc8->to_idx; i++) + for (i = from; i <= to; i++) crc = crc8->crctab[crc ^ cf->data[i]]; } else { - for (i = crc8->from_idx; i >= crc8->to_idx; i--) + for (i = from; i >= to; i--) crc = crc8->crctab[crc ^ cf->data[i]]; } @@ -397,7 +397,7 @@ static void cgw_csum_crc8_rel(struct canfd_frame *cf, break; } - cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val; + cf->data[res] = crc ^ crc8->final_xor_val; } static void cgw_csum_crc8_pos(struct canfd_frame *cf, From 424e95d62110cdbc8fd12b40918f37e408e35a92 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Thu, 19 Mar 2026 16:47:45 +0100 Subject: [PATCH 5/5] can: isotp: fix tx.buf use-after-free in isotp_sendmsg() isotp_sendmsg() uses only cmpxchg() on so->tx.state to serialize access to so->tx.buf. isotp_release() waits for ISOTP_IDLE via wait_event_interruptible() and then calls kfree(so->tx.buf). If a signal interrupts the wait_event_interruptible() inside close() while tx.state is ISOTP_SENDING, the loop exits early and release proceeds to force ISOTP_SHUTDOWN and continues to kfree(so->tx.buf) while sendmsg may still be reading so->tx.buf for the final CAN frame in isotp_fill_dataframe(). The so->tx.buf can be allocated once when the standard tx.buf length needs to be extended. Move the kfree() of this potentially extended tx.buf to sk_destruct time when either isotp_sendmsg() and isotp_release() are done. Fixes: 96d1c81e6a04 ("can: isotp: add module parameter for maximum pdu size") Cc: stable@vger.kernel.org Reported-by: Ali Norouzi Co-developed-by: Ali Norouzi Signed-off-by: Ali Norouzi Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260319-fix-can-gw-and-can-isotp-v2-2-c45d52c6d2d8@pengutronix.de Signed-off-by: Marc Kleine-Budde --- net/can/isotp.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/net/can/isotp.c b/net/can/isotp.c index da3b72e7afcc..2770f43f4951 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -1248,12 +1248,6 @@ static int isotp_release(struct socket *sock) so->ifindex = 0; so->bound = 0; - if (so->rx.buf != so->rx.sbuf) - kfree(so->rx.buf); - - if (so->tx.buf != so->tx.sbuf) - kfree(so->tx.buf); - sock_orphan(sk); sock->sk = NULL; @@ -1622,6 +1616,21 @@ static int isotp_notifier(struct notifier_block *nb, unsigned long msg, return NOTIFY_DONE; } +static void isotp_sock_destruct(struct sock *sk) +{ + struct isotp_sock *so = isotp_sk(sk); + + /* do the standard CAN sock destruct work */ + can_sock_destruct(sk); + + /* free potential extended PDU buffers */ + if (so->rx.buf != so->rx.sbuf) + kfree(so->rx.buf); + + if (so->tx.buf != so->tx.sbuf) + kfree(so->tx.buf); +} + static int isotp_init(struct sock *sk) { struct isotp_sock *so = isotp_sk(sk); @@ -1666,6 +1675,9 @@ static int isotp_init(struct sock *sk) list_add_tail(&so->notifier, &isotp_notifier_list); spin_unlock(&isotp_notifier_lock); + /* re-assign default can_sock_destruct() reference */ + sk->sk_destruct = isotp_sock_destruct; + return 0; }