CVE-2025-38311 Information

Jul 12, 2025 cve

Description

In the Linux kernel the following vulnerability has been resolved:

iavf: get rid of the crit lock

Get rid of the crit lock. That frees us from the error prone logic of try_locks.

Thanks to netdev_lock() by Jakub it is now easy and in most cases we were protected by it already - replace crit lock by netdev lock when it was not the case.

Lockdep reports that we should cancel the work under crit_lock [splat1] and that was the scheme we have mostly followed since [1] by Slawomir. But when that is done we still got into deadlocks [splat2]. So instead we should look at the bigger problem namely \weird locking/scheduling\nof the iavf. The first step to fix that is to remove the crit lock. I will followup with a -next series that simplifies scheduling/tasks.

Cancel the work without netdev lock (weird unlock+lock scheme) to fix the [splat2] (which would be totally ugly if we would kept the crit lock).

Extend protected part of iavf_watchdog_task() to include scheduling more work.

Note that the removed comment in iavf_reset_task() was misplaced it belonged to inside of the removed if condition so it’s gone now.

[splat1] - w/o this patch - The deadlock during VF removal: WARNING: possible circular locking dependency detected sh/3825 is trying to acquire lock: ((work_completion)(&(&adapter->watchdog_task)->work))+.+.-0:0 at: start_flush_work+0x1a1/0x470 but task is already holding lock: (&adapter->crit_lock)+.+.-4:4 at: iavf_remove+0xd1/0x690 [iavf] which lock already depends on the new lock.

[splat2] - when cancelling work under crit lock w/o this series see [2] for the band aid attempt WARNING: possible circular locking dependency detected sh/3550 is trying to acquire lock: ((wq_completion)iavf)+.+.-0:0 at: touch_wq_lockdep_map+0x26/0x90 but task is already holding lock: (&dev->lock)+.+.-4:4 at: iavf_remove+0xa6/0x6e0 [iavf] which lock already depends on the new lock.

[1] fc2e6b3b132a (\iavf: Rework mutexes for better synchronisation) [2] https://github.com/pkitszel/linux/commit/52dddbfc2bb60294083f5711a158a

Reference

https://git.kernel.org/stable/c/120f28a6f314fef7f282c99f196923fe44081cad https://git.kernel.org/stable/c/620ab4d6215de0b25227f9fff1a8c7fb66837cb8

CNNVD-202507-1435 (Published: 2025-07-10)

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