ALSA: aloop: Fix racy access at PCM trigger

Answer in brief

CVE-2026-23191 records a Unknown severity vulnerability in ALSA: aloop: Fix racy access at PCM trigger. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Feb 14, 2026Updated Sep 14, 2026Source checked Sep 14, 2026First seen by HOL Sep 14, 2026Material review Sep 14, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=b1c73fc8e697eb73e23603e465e9af2711ed4183 <f57467114f40c5aacebbea96fb4ff9e5cd2b7f18 \|\| >=b1c73fc8e697eb73e23603e465e9af2711ed4183 <c99be0d5af02adebe9cb6f9869d20397fa9935a3 \|\| >=b1c73fc8e697eb73e23603e465e9af2711ed4183 <f3ce8be893726899e3053cf8059ecc95d8410359 \|\| >=b1c73fc8e697eb73e23603e465e9af2711ed4183 <0e6245b2424d126ac90018142d09f0707e12998b \|\| >=b1c73fc8e697eb73e23603e465e9af2711ed4183 <bad15420050db1803767e58756114800cce91ea4 \|\| >=b1c73fc8e697eb73e23603e465e9af2711ed4183 <5727ccf9d19ca414cb76d9b647883822e2789c2e \|\| >=b1c73fc8e697eb73e23603e465e9af2711ed4183 <826af7fa62e347464b1b4e0ba2fe19a92438084f	f57467114f40c5aacebbea96fb4ff9e5cd2b7f18, c99be0d5af02adebe9cb6f9869d20397fa9935a3, f3ce8be893726899e3053cf8059ecc95d8410359, 0e6245b2424d126ac90018142d09f0707e12998b, bad15420050db1803767e58756114800cce91ea4, 5727ccf9d19ca414cb76d9b647883822e2789c2e, 826af7fa62e347464b1b4e0ba2fe19a92438084f
Linux/Linuxgeneric	2.6.37	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to f57467114f40c5aacebbea96fb4ff9e5cd2b7f18 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Feb 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 14, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: ALSA: aloop: Fix racy access at PCM trigger The PCM trigger callback of aloop driver tries to check the PCM state and stop the stream of the tied substream in the corresponding cable. Since both check and stop operations are performed outside the cable lock, this may result in UAF when a program attempts to trigger frequently while opening/closing the tied stream, as spotted by fuzzers. For addressing the UAF, this patch changes two things: - It covers the most of code in loopback_check_format() with cable->lock spinlock, and add the proper NULL checks. This avoids already some racy accesses. - In addition, now we try to check the state of the capture PCM stream that may be stopped in this function, which was the major pain point leading to UAF.

Quoted source text, attributed separately from HOL analysis.