CVE-2026-43437 (GCVE-0-2026-43437)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:22 – Updated: 2026-05-11 22:24
VLAI
Title
ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain()
Summary
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.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: f2b3614cefb61ee6046a0aaee503ee37f227d310 , < 9baee36e8c5443411c4629afabafaff8a46a23fd (git)
Affected: f2b3614cefb61ee6046a0aaee503ee37f227d310 , < fc71f888994569f87d5bee20b1ac6c9c1e3a7a79 (git)
Affected: f2b3614cefb61ee6046a0aaee503ee37f227d310 , < 629cf09464cf98670996ea5c191dc9743e6f3f00 (git)
Affected: f2b3614cefb61ee6046a0aaee503ee37f227d310 , < ae8f8d30d334bad5b1b3cdb1eb8a0b771f55e432 (git)
Affected: f2b3614cefb61ee6046a0aaee503ee37f227d310 , < 4a758e9a1f5ed722f83c4dd35f867fe811553bcb (git)
Affected: f2b3614cefb61ee6046a0aaee503ee37f227d310 , < c2f64e05a0587a83ec42dbd6b7a7ded79b2ff694 (git)
Affected: f2b3614cefb61ee6046a0aaee503ee37f227d310 , < 9b1dbd69ba6f8f8c69bc7b77c2ce3b9c6ed05ba6 (git)
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Linux Linux Affected: 3.0
Unaffected: 0 , < 3.0 (semver)
Unaffected: 5.10.253 , ≤ 5.10.* (semver)
Unaffected: 6.1.167 , ≤ 6.1.* (semver)
Unaffected: 6.6.130 , ≤ 6.6.* (semver)
Unaffected: 6.12.78 , ≤ 6.12.* (semver)
Unaffected: 6.18.19 , ≤ 6.18.* (semver)
Unaffected: 6.19.9 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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}


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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.