Bug 2347842 (CVE-2022-49291)

Summary: CVE-2022-49291 kernel: ALSA: pcm: Fix races among concurrent hw_params and hw_free calls
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-26 03:08:39 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ALSA: pcm: Fix races among concurrent hw_params and hw_free calls

Currently we have neither proper check nor protection against the
concurrent calls of PCM hw_params and hw_free ioctls, which may result
in a UAF.  Since the existing PCM stream lock can't be used for
protecting the whole ioctl operations, we need a new mutex to protect
those racy calls.

This patch introduced a new mutex, runtime->buffer_mutex, and applies
it to both hw_params and hw_free ioctl code paths.  Along with it, the
both functions are slightly modified (the mmap_count check is moved
into the state-check block) for code simplicity.
Comment 1 Avinash Hanwate 2025-02-26 20:10:30 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022633-CVE-2022-49291-8c67@gregkh/T
Comment 4 Avinash Hanwate 2025-02-28 01:18:41 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022633-CVE-2022-49291-8c67@gregkh/T