Bug 2502402 (CVE-2026-64001)

Summary: CVE-2026-64001 kernel: ALSA: pcm: oss: Fix setup list UAF on proc write error
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's ALSA (Advanced Linux Sound Architecture) PCM (Pulse Code Modulation) OSS (Open Sound System) component. A local user could exploit a Use-After-Free (UAF) vulnerability in the `snd_pcm_oss_proc_write()` function. This occurs when a setup entry is prematurely linked into the OSS setup list, and a subsequent task-name allocation failure leads to the entry being freed while still referenced. A later attempt to open an OSS device could then access this freed memory, potentially leading to memory corruption or system instability.
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Description OSIDB Bzimport 2026-07-19 16:06:14 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ALSA: pcm: oss: Fix setup list UAF on proc write error

snd_pcm_oss_proc_write() links a newly allocated setup entry into the
OSS setup list before duplicating the task name. If the task-name
allocation fails, the error path frees the already linked entry and
leaves setup_list pointing at freed memory.

A later OSS device open can then walk the stale list entry in
snd_pcm_oss_look_for_setup() and dereference freed memory.

Allocate the task name and initialize the setup entry before publishing
the entry on setup_list. Also fetch the initial proc read iterator only
after taking setup_mutex, so all setup_list traversal follows the same
list lifetime rules.
Comment 1 Keith Grant 2026-07-21 23:55:13 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026071906-CVE-2026-64001-48e3@gregkh/T