CVE-2026-43437ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain()
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from f2b3614cefb61ee6046a0aaee503ee37f227d310 before 9baee36e8c5443411c4629afabafaff8a46a23fd; from f2b3614cefb61ee6046a0aaee503ee37f227d310 before f2cb2e0d27fb925c73a78f0ce7d6dbf68d3747c1; from f2b3614cefb61ee6046a0aaee503ee37f227d310 before fc71f888994569f87d5bee20b1ac6c9c1e3a7a79; from f2b3614cefb61ee6046a0aaee503ee37f227d310 before 629cf09464cf98670996ea5c191dc9743e6f3f00; from f2b3614cefb61ee6046a0aaee503ee37f227d310 before ae8f8d30d334bad5b1b3cdb1eb8a0b771f55e432; from f2b3614cefb61ee6046a0aaee503ee37f227d310 before 4a758e9a1f5ed722f83c4dd35f867fe811553bcb; from f2b3614cefb61ee6046a0aaee503ee37f227d310 before c2f64e05a0587a83ec42dbd6b7a7ded79b2ff694; from f2b3614cefb61ee6046a0aaee503ee37f227d310 before 9b1dbd69ba6f8f8c69bc7b77c2ce3b9c6ed05ba6 | CNA record |
linux linux_kernel linux:linux_kernel | from 3.0 before 5.10.253; from 5.11 before 6.1.167; from 6.2 before 6.6.130; from 6.7 before 6.12.78; from 6.13 before 6.18.19; from 6.19 before 6.19.9; 7.0; 7.0; and 1 more ranges | NVD |
References
- https://git.kernel.org/stable/c/9baee36e8c5443411c4629afabafaff8a46a23fdpatch
- https://git.kernel.org/stable/c/f2cb2e0d27fb925c73a78f0ce7d6dbf68d3747c1
- https://git.kernel.org/stable/c/fc71f888994569f87d5bee20b1ac6c9c1e3a7a79patch
- https://git.kernel.org/stable/c/629cf09464cf98670996ea5c191dc9743e6f3f00patch
- https://git.kernel.org/stable/c/ae8f8d30d334bad5b1b3cdb1eb8a0b771f55e432patch
- https://git.kernel.org/stable/c/4a758e9a1f5ed722f83c4dd35f867fe811553bcbpatch
- https://git.kernel.org/stable/c/c2f64e05a0587a83ec42dbd6b7a7ded79b2ff694patch
- https://git.kernel.org/stable/c/9b1dbd69ba6f8f8c69bc7b77c2ce3b9c6ed05ba6patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.