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.
References
Configurations
Configuration 1 (hide)
|
History
21 May 2026, 17:41
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| References | () https://git.kernel.org/stable/c/4a758e9a1f5ed722f83c4dd35f867fe811553bcb - Patch | |
| References | () https://git.kernel.org/stable/c/629cf09464cf98670996ea5c191dc9743e6f3f00 - Patch | |
| References | () https://git.kernel.org/stable/c/9b1dbd69ba6f8f8c69bc7b77c2ce3b9c6ed05ba6 - Patch | |
| References | () https://git.kernel.org/stable/c/9baee36e8c5443411c4629afabafaff8a46a23fd - Patch | |
| References | () https://git.kernel.org/stable/c/ae8f8d30d334bad5b1b3cdb1eb8a0b771f55e432 - Patch | |
| References | () https://git.kernel.org/stable/c/c2f64e05a0587a83ec42dbd6b7a7ded79b2ff694 - Patch | |
| References | () https://git.kernel.org/stable/c/fc71f888994569f87d5bee20b1ac6c9c1e3a7a79 - Patch | |
| CWE | CWE-416 | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* |
11 May 2026, 08:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
08 May 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-08 15:16
Updated : 2026-05-21 17:41
NVD link : CVE-2026-43437
Mitre link : CVE-2026-43437
CVE.ORG link : CVE-2026-43437
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-416
Use After Free