Use After Free Affecting gfs2-kmp-default package, versions <5.14.21-150400.24.219.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.13% (3rd percentile)

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  • Snyk IDSNYK-SLES154-GFS2KMPDEFAULT-17123724
  • published2 Jun 2026
  • disclosed1 Jun 2026

Introduced: 1 Jun 2026

CVE-2026-43437  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade SLES:15.4 gfs2-kmp-default to version 5.14.21-150400.24.219.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream gfs2-kmp-default package and not the gfs2-kmp-default package as distributed by SLES. See How to fix? for SLES:15.4 relevant fixed versions and status.

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

ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain()

In the drain loop, the local variable 'runtime' is reassigned to a linked stream's runtime (runtime = s->runtime at line 2157). After releasing the stream lock at line 2169, the code accesses runtime->no_period_wakeup, runtime->rate, and runtime->buffer_size (lines 2170-2178) — all referencing the linked stream's runtime without any lock or refcount protecting its lifetime.

A concurrent close() on the linked stream's fd triggers snd_pcm_release_substream() → snd_pcm_drop() → pcm_release_private() → snd_pcm_unlink() → snd_pcm_detach_substream() → kfree(runtime). No synchronization prevents kfree(runtime) from completing while the drain path dereferences the stale pointer.

Fix by caching the needed runtime fields (no_period_wakeup, rate, buffer_size) into local variables while still holding the stream lock, and using the cached values after the lock is released.

CVSS Base Scores

version 3.1