CVE-2021-46931 net/mlx5e: Wrap the tx reporter dump callback to extract the sq
A type confusion bug in the Mellanox mlx5 network driver causes a kernel stack overflow and panic during TX timeout recovery, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-46931?
CVE-2021-46931 is a medium-severity memory corruption vulnerability in Linux kernel, published on 27 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Wrap the tx reporter dump callback to extract the sq
Function mlx5e_tx_reporter_dump_sq() casts its void * argument to struct mlx5e_txqsq *, but in TX-timeout-recovery flow the argument is actually of type struct mlx5e_tx_timeout_ctx *.
mlx5_core 0000:08:00.1 enp8s0f1: TX timeout detected mlx5_core 0000:08:00.1 enp8s0f1: TX timeout on queue: 1, SQ: 0x11ec, CQ: 0x146d, SQ Cons: 0x0 SQ Prod: 0x1, usecs since last trans: 21565000 BUG: stack guard page was hit at 0000000093f1a2de (stack is 00000000b66ea0dc..000000004d932dae) kernel stack overflow (page fault): 0000 [#1] SMP NOPTI CPU: 5 PID: 95 Comm: kworker/u20:1 Tainted: G W OE 5.13.0_mlnx #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: mlx5e mlx5e_tx_timeout_work [mlx5_core] RIP: 0010:mlx5e_tx_reporter_dump_sq+0xd3/0x180 [mlx5_core] Call Trace: mlx5e_tx_reporter_dump+0x43/0x1c0 [mlx5_core] devlink_health_do_dump.part.91+0x71/0xd0 devlink_health_report+0x157/0x1b0 mlx5e_reporter_tx_timeout+0xb9/0xf0 [mlx5_core] ? mlx5e_tx_reporter_err_cqe_recover+0x1d0/0x1d0 [mlx5_core] ? mlx5e_health_queue_dump+0xd0/0xd0 [mlx5_core] ? update_load_avg+0x19b/0x550 ? set_next_entity+0x72/0x80 ? pick_next_task_fair+0x227/0x340 ? finish_task_switch+0xa2/0x280 mlx5e_tx_timeout_work+0x83/0xb0 [mlx5_core] process_one_work+0x1de/0x3a0 worker_thread+0x2d/0x3c0 ? process_one_work+0x3a0/0x3a0 kthread+0x115/0x130 ? kthread_park+0x90/0x90 ret_from_fork+0x1f/0x30 --[ end trace 51ccabea504edaff ]--- RIP: 0010:mlx5e_tx_reporter_dump_sq+0xd3/0x180 PKRU: 55555554 Kernel panic - not syncing: Fatal exception Kernel Offset: disabled end Kernel panic - not syncing: Fatal exception
To fix this bug add a wrapper for mlx5e_tx_reporter_dump_sq() which extracts the sq from struct mlx5e_tx_timeout_ctx and set it as the TX-timeout-recovery flow dump callback.
Weakness: CWE-787
Which versions are affected by CVE-2021-46931?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-46931?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-46931 being exploited?
There is no known exploitation of CVE-2021-46931 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-46931, GHSA-5gx7-f5j6-6r9q, UBUNTU-CVE-2021-46931.