CVE-2025-21970

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Bridge, fix the crash caused by LAG state check When removing LAG device from bridge, NETDEV_CHANGEUPPER event is triggered. Driver finds the lower devices (PFs) to flush all the offloaded entries. And mlx5_lag_is_shared_fdb is checked, it returns false if one of PF is unloaded. In such case, mlx5_esw_bridge_lag_rep_get() and its caller return NULL, instead of the alive PF, and the flush is skipped. Besides, the bridge fdb entry's lastuse is updated in mlx5 bridge event handler. But this SWITCHDEV_FDB_ADD_TO_BRIDGE event can be ignored in this case because the upper interface for bond is deleted, and the entry will never be aged because lastuse is never updated. To make things worse, as the entry is alive, mlx5 bridge workqueue keeps sending that event, which is then handled by kernel bridge notifier. It causes the following crash when accessing the passed bond netdev which is already destroyed. To fix this issue, remove such checks. LAG state is already checked in commit 15f8f168952f ("net/mlx5: Bridge, verify LAG state when adding bond to bridge"), driver still need to skip offload if LAG becomes invalid state after initialization. Oops: stack segment: 0000 [#1] SMP CPU: 3 UID: 0 PID: 23695 Comm: kworker/u40:3 Tainted: G OE 6.11.0_mlnx #1 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: mlx5_bridge_wq mlx5_esw_bridge_update_work [mlx5_core] RIP: 0010:br_switchdev_event+0x2c/0x110 [bridge] Code: 44 00 00 48 8b 02 48 f7 00 00 02 00 00 74 69 41 54 55 53 48 83 ec 08 48 8b a8 08 01 00 00 48 85 ed 74 4a 48 83 fe 02 48 89 d3 <4c> 8b 65 00 74 23 76 49 48 83 fe 05 74 7e 48 83 fe 06 75 2f 0f b7 RSP: 0018:ffffc900092cfda0 EFLAGS: 00010297 RAX: ffff888123bfe000 RBX: ffffc900092cfe08 RCX: 00000000ffffffff RDX: ffffc900092cfe08 RSI: 0000000000000001 RDI: ffffffffa0c585f0 RBP: 6669746f6e690a30 R08: 0000000000000000 R09: ffff888123ae92c8 R10: 0000000000000000 R11: fefefefefefefeff R12: ffff888123ae9c60 R13: 0000000000000001 R14: ffffc900092cfe08 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88852c980000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f15914c8734 CR3: 0000000002830005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __die_body+0x1a/0x60 ? die+0x38/0x60 ? do_trap+0x10b/0x120 ? do_error_trap+0x64/0xa0 ? exc_stack_segment+0x33/0x50 ? asm_exc_stack_segment+0x22/0x30 ? br_switchdev_event+0x2c/0x110 [bridge] ? sched_balance_newidle.isra.149+0x248/0x390 notifier_call_chain+0x4b/0xa0 atomic_notifier_call_chain+0x16/0x20 mlx5_esw_bridge_update+0xec/0x170 [mlx5_core] mlx5_esw_bridge_update_work+0x19/0x40 [mlx5_core] process_scheduled_works+0x81/0x390 worker_thread+0x106/0x250 ? bh_worker+0x110/0x110 kthread+0xb7/0xe0 ? kthread_park+0x80/0x80 ret_from_fork+0x2d/0x50 ? kthread_park+0x80/0x80 ret_from_fork_asm+0x11/0x20 </TASK>
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*

History

31 Oct 2025, 19:16

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/4b8eeed4fb105770ce6dc84a2c6ef953c7b71cbb - () https://git.kernel.org/stable/c/4b8eeed4fb105770ce6dc84a2c6ef953c7b71cbb - Patch
References () https://git.kernel.org/stable/c/5dd8bf6ab1d6db40f5d09603759fa88caec19e7f - () https://git.kernel.org/stable/c/5dd8bf6ab1d6db40f5d09603759fa88caec19e7f - Patch
References () https://git.kernel.org/stable/c/86ff45f5f61ae1d0d17f0f6d8797b052eacfd8f1 - () https://git.kernel.org/stable/c/86ff45f5f61ae1d0d17f0f6d8797b052eacfd8f1 - Patch
References () https://git.kernel.org/stable/c/bd7e3a42800743a7748c83243e4cafc1b995d4c4 - () https://git.kernel.org/stable/c/bd7e3a42800743a7748c83243e4cafc1b995d4c4 - Patch
References () https://git.kernel.org/stable/c/f7bf259a04271165ae667ad21cfc60c6413f25ca - () https://git.kernel.org/stable/c/f7bf259a04271165ae667ad21cfc60c6413f25ca - Patch
References () https://git.kernel.org/stable/c/f90c4d6572488e2bad38cca00f1c59174a538a1a - () https://git.kernel.org/stable/c/f90c4d6572488e2bad38cca00f1c59174a538a1a - Patch
CPE cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5
CWE CWE-476

10 Apr 2025, 13:15

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/f90c4d6572488e2bad38cca00f1c59174a538a1a -
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/mlx5: Puente, corrige el fallo causado por la comprobación del estado de LAG Al retirar el dispositivo LAG del puente, se activa el evento NETDEV_CHANGEUPPER. El controlador encuentra los dispositivos inferiores (PF) para vaciar todas las entradas descargadas. Y mlx5_lag_is_shared_fdb está marcado, devuelve falso si uno de los PF está descargado. En tal caso, mlx5_esw_bridge_lag_rep_get() y su llamador devuelven NULL, en lugar del PF vivo, y se omite el vaciado. Además, el lastuse de la entrada fdb del puente se actualiza en el controlador de eventos del puente mlx5. Pero este evento SWITCHDEV_FDB_ADD_TO_BRIDGE se puede ignorar en este caso porque se elimina la interfaz superior para el enlace y la entrada nunca se envejecerá porque lastuse nunca se actualiza. Para empeorar las cosas, mientras la entrada esté activa, la cola de trabajo del puente mlx5 sigue enviando ese evento, que luego gestiona el notificador del puente del núcleo. Esto provoca el siguiente fallo al acceder al enlace transferido netdev, que ya está destruido. Para solucionar este problema, elimine estas comprobaciones. El estado de LAG ya se comprobó en el commit 15f8f168952f ("net/mlx5: Puente, verificar el estado de LAG al agregar el enlace al puente"). El controlador aún debe omitir la descarga si el estado de LAG se vuelve inválido después de la inicialización. Ups: segmento de pila: 0000 [#1] CPU SMP: 3 UID: 0 PID: 23695 Comm: kworker/u40:3 Contaminado: G OE 6.11.0_mlnx #1 Contaminado: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Nombre del hardware: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: mlx5_bridge_wq mlx5_esw_bridge_update_work [mlx5_core] RIP: 0010:br_switchdev_event+0x2c/0x110 [bridge] Code: 44 00 00 48 8b 02 48 f7 00 00 02 00 00 74 69 41 54 55 53 48 83 ec 08 48 8b a8 08 01 00 00 48 85 ed 74 4a 48 83 fe 02 48 89 d3 &lt;4c&gt; 8b 65 00 74 23 76 49 48 83 fe 05 74 7e 48 83 fe 06 75 2f 0f b7 RSP: 0018:ffffc900092cfda0 EFLAGS: 00010297 RAX: ffff888123bfe000 RBX: ffffc900092cfe08 RCX: 00000000ffffffff RDX: ffffc900092cfe08 RSI: 0000000000000001 RDI: ffffffffa0c585f0 RBP: 6669746f6e690a30 R08: 0000000000000000 R09: ffff888123ae92c8 R10: 0000000000000000 R11: fefefefefefefeff R12: ffff888123ae9c60 R13: 0000000000000001 R14: ffffc900092cfe08 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88852c980000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f15914c8734 CR3: 0000000002830005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? __die_body+0x1a/0x60 ? die+0x38/0x60 ? do_trap+0x10b/0x120 ? do_error_trap+0x64/0xa0 ? exc_stack_segment+0x33/0x50 ? asm_exc_stack_segment+0x22/0x30 ? br_switchdev_event+0x2c/0x110 [bridge] ? sched_balance_newidle.isra.149+0x248/0x390 notifier_call_chain+0x4b/0xa0 atomic_notifier_call_chain+0x16/0x20 mlx5_esw_bridge_update+0xec/0x170 [mlx5_core] mlx5_esw_bridge_update_work+0x19/0x40 [mlx5_core] process_scheduled_works+0x81/0x390 worker_thread+0x106/0x250 ? bh_worker+0x110/0x110 kthread+0xb7/0xe0 ? kthread_park+0x80/0x80 ret_from_fork+0x2d/0x50 ? kthread_park+0x80/0x80 ret_from_fork_asm+0x11/0x20

01 Apr 2025, 16:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-04-01 16:15

Updated : 2025-10-31 19:16


NVD link : CVE-2025-21970

Mitre link : CVE-2025-21970

CVE.ORG link : CVE-2025-21970


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-476

NULL Pointer Dereference