Bug 2394618 (CVE-2025-39768)

Summary: CVE-2025-39768 kernel: net/mlx5: HWS, fix complex rules rehash error flow
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-09-11 17:02:43 UTC
In the Linux kernel, the following vulnerability has been resolved:

net/mlx5: HWS, fix complex rules rehash error flow

Moving rules from matcher to matcher should not fail.
However, if it does fail due to various reasons, the error flow
should allow the kernel to continue functioning (albeit with broken
steering rules) instead of going into series of soft lock-ups or
some other problematic behaviour.

Similar to the simple rules, complex rules rehash logic suffers
from the same problems. This patch fixes the error flow for moving
complex rules:
 - If new rule creation fails before it was even enqeued, do not
   poll for completion
 - If TIMEOUT happened while moving the rule, no point trying
   to poll for completions for other rules. Something is broken,
   completion won't come, just abort the rehash sequence.
 - If some other completion with error received, don't give up.
   Continue handling rest of the rules to minimize the damage.
 - Make sure that the first error code that was received will
   be actually returned to the caller instead of replacing it
   with the generic error code.

All the aforementioned issues stem from the same bad error flow,
so no point fixing them one by one and leaving partially broken
code - fixing them in one patch.