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CVE-2025-21853 The advisory has been revoked - it doesn't affect any version of package kernel-debug-devel-matched  (opens in a new tab)

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0.02% (6th percentile)

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  • Snyk IDSNYK-ALMALINUX10-KERNELDEBUGDEVELMATCHED-14120668
  • published26 Nov 2025
  • disclosed11 Nov 2025
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Introduced: 11 Nov 2025

CVE-2025-21853  (opens in a new tab)

Amendment

The AlmaLinux security team deemed this advisory irrelevant for AlmaLinux:10.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-debug-devel-matched package and not the kernel-debug-devel-matched package as distributed by AlmaLinux.

In the Linux kernel, the following vulnerability has been resolved:

bpf: avoid holding freeze_mutex during mmap operation

We use map->freeze_mutex to prevent races between map_freeze() and memory mapping BPF map contents with writable permissions. The way we naively do this means we'll hold freeze_mutex for entire duration of all the mm and VMA manipulations, which is completely unnecessary. This can potentially also lead to deadlocks, as reported by syzbot in [0].

So, instead, hold freeze_mutex only during writeability checks, bump (proactively) "write active" count for the map, unlock the mutex and proceed with mmap logic. And only if something went wrong during mmap logic, then undo that "write active" counter increment.

[0] https://lore.kernel.org/bpf/678dcbc9.050a0220.303755.0066.GAE@google.com/

References