kernel/linux.git/net/can, branch v6.12.91

can: raw: fix ro->uniq use-after-free in raw_rcv()

2026-04-22T11:18:56+00:00

commit a535a9217ca3f2fccedaafb2fddb4c48f27d36dc upstream. raw_release() unregisters raw CAN receive filters via can_rx_unregister(), but receiver deletion is deferred with call_rcu(). This leaves a window where raw_rcv() may still be running in an RCU read-side critical section after raw_release() frees ro->uniq, leading to a use-after-free of the percpu uniq storage. Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific socket destructor. can_rx_unregister() takes an extra reference to the socket and only drops it from the RCU callback, so freeing uniq from sk_destruct ensures the percpu area is not released until the relevant callbacks have drained. Fixes: 514ac99c64b2 ("can: fix multiple delivery of a single CAN frame for overlapping CAN filters") Cc: stable@vger.kernel.org # v4.1+ Assisted-by: Bynario AI Signed-off-by: Samuel Page Link: https://patch.msgid.link/26ec626d-cae7-4418-9782-7198864d070c@bynar.io Acked-by: Oliver Hartkopp [mkl: applied manually] Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: isotp: fix tx.buf use-after-free in isotp_sendmsg()

2026-04-02T11:09:42+00:00

commit 424e95d62110cdbc8fd12b40918f37e408e35a92 upstream. 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 Signed-off-by: Greg Kroah-Hartman

can: gw: fix OOB heap access in cgw_csum_crc8_rel()

2026-04-02T11:09:42+00:00

commit b9c310d72783cc2f30d103eed83920a5a29c671a upstream. 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 Signed-off-by: Greg Kroah-Hartman

can: statistics: add missing atomic access in hot path

2026-04-02T11:09:31+00:00

[ Upstream commit 46eee1661aa9b49966e6c43d07126fe408edda57 ] 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 Signed-off-by: Sasha Levin

can: bcm: fix locking for bcm_op runtime updates

2026-03-13T16:20:40+00:00

[ Upstream commit c35636e91e392e1540949bbc67932167cb48bc3a ] Commit c2aba69d0c36 ("can: bcm: add locking for bcm_op runtime updates") added a locking for some variables that can be modified at runtime when updating the sending bcm_op with a new TX_SETUP command in bcm_tx_setup(). Usually the RX_SETUP only handles and filters incoming traffic with one exception: When the RX_RTR_FRAME flag is set a predefined CAN frame is sent when a specific RTR frame is received. Therefore the rx bcm_op uses bcm_can_tx() which uses the bcm_tx_lock that was only initialized in bcm_tx_setup(). Add the missing spin_lock_init() when allocating the bcm_op in bcm_rx_setup() to handle the RTR case properly. Fixes: c2aba69d0c36 ("can: bcm: add locking for bcm_op runtime updates") Reported-by: syzbot+5b11eccc403dd1cea9f8@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-can/699466e4.a70a0220.2c38d7.00ff.GAE@google.com/ Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260218-bcm_spin_lock_init-v1-1-592634c8a5b5@hartkopp.net Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin

net: can: j1939: j1939_xtp_rx_rts_session_active(): deactivate session upon receiving the second rts

2026-01-23T10:18:43+00:00

commit 1809c82aa073a11b7d335ae932d81ce51a588a4a upstream. Since j1939_session_deactivate_activate_next() in j1939_tp_rxtimer() is called only when the timer is enabled, we need to call j1939_session_deactivate_activate_next() if we cancelled the timer. Otherwise, refcount for j1939_session leaks, which will later appear as | unregister_netdevice: waiting for vcan0 to become free. Usage count = 2. problem. Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=881d65229ca4f9ae8c84 Signed-off-by: Tetsuo Handa Tested-by: Oleksij Rempel Acked-by: Oleksij Rempel Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Link: https://patch.msgid.link/b1212653-8fa1-44e1-be9d-12f950fb3a07@I-love.SAKURA.ne.jp Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: j1939: make j1939_session_activate() fail if device is no longer registered

2026-01-17T15:31:28+00:00

[ Upstream commit 5d5602236f5db19e8b337a2cd87a90ace5ea776d ] syzbot is still reporting unregister_netdevice: waiting for vcan0 to become free. Usage count = 2 even after commit 93a27b5891b8 ("can: j1939: add missing calls in NETDEV_UNREGISTER notification handler") was added. A debug printk() patch found that j1939_session_activate() can succeed even after j1939_cancel_active_session() from j1939_netdev_notify(NETDEV_UNREGISTER) has completed. Since j1939_cancel_active_session() is processed with the session list lock held, checking ndev->reg_state in j1939_session_activate() with the session list lock held can reliably close the race window. Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=881d65229ca4f9ae8c84 Signed-off-by: Tetsuo Handa Acked-by: Oleksij Rempel Link: https://patch.msgid.link/b9653191-d479-4c8b-8536-1326d028db5c@I-love.SAKURA.ne.jp Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin

can: j1939: j1939_local_ecu_get(): undo increment when j1939_local_ecu_get() fails

2025-09-19T14:35:49+00:00

[ Upstream commit 06e02da29f6f1a45fc07bd60c7eaf172dc21e334 ] Since j1939_sk_bind() and j1939_sk_release() call j1939_local_ecu_put() when J1939_SOCK_BOUND was already set, but the error handling path for j1939_sk_bind() will not set J1939_SOCK_BOUND when j1939_local_ecu_get() fails, j1939_local_ecu_get() needs to undo priv->ents[sa].nusers++ when j1939_local_ecu_get() returns an error. Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Signed-off-by: Tetsuo Handa Tested-by: Oleksij Rempel Acked-by: Oleksij Rempel Link: https://patch.msgid.link/e7f80046-4ff7-4ce2-8ad8-7c3c678a42c9@I-love.SAKURA.ne.jp Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin

can: j1939: j1939_sk_bind(): call j1939_priv_put() immediately when j1939_local_ecu_get() failed

2025-09-19T14:35:49+00:00

[ Upstream commit f214744c8a27c3c1da6b538c232da22cd027530e ] Commit 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback") expects that a call to j1939_priv_put() can be unconditionally delayed until j1939_sk_sock_destruct() is called. But a refcount leak will happen when j1939_sk_bind() is called again after j1939_local_ecu_get() from previous j1939_sk_bind() call returned an error. We need to call j1939_priv_put() before j1939_sk_bind() returns an error. Fixes: 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback") Signed-off-by: Tetsuo Handa Tested-by: Oleksij Rempel Acked-by: Oleksij Rempel Link: https://patch.msgid.link/4f49a1bc-a528-42ad-86c0-187268ab6535@I-love.SAKURA.ne.jp Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin

can: bcm: add missing rcu read protection for procfs content

2025-05-29T09:03:19+00:00

commit dac5e6249159ac255dad9781793dbe5908ac9ddb upstream. When the procfs content is generated for a bcm_op which is in the process to be removed the procfs output might show unreliable data (UAF). As the removal of bcm_op's is already implemented with rcu handling this patch adds the missing rcu_read_lock() and makes sure the list entries are properly removed under rcu protection. Fixes: f1b4e32aca08 ("can: bcm: use call_rcu() instead of costly synchronize_rcu()") Reported-by: Anderson Nascimento Suggested-by: Anderson Nascimento Tested-by: Anderson Nascimento Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20250519125027.11900-2-socketcan@hartkopp.net Cc: stable@vger.kernel.org # >= 5.4 Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman