ALSA: usb-audio: fix race condition to UAF in snd_usbmidi_free

Summary

CVECVE-2025-39997
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-10-15 08:15:37 UTC
Updated2026-06-01 17:16:36 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: fix race condition to UAF in snd_usbmidi_free The previous commit 0718a78f6a9f ("ALSA: usb-audio: Kill timer properly at removal") patched a UAF issue caused by the error timer. However, because the error timer kill added in this patch occurs after the endpoint delete, a race condition to UAF still occurs, albeit rarely. Additionally, since kill-cleanup for urb is also missing, freed memory can be accessed in interrupt context related to urb, which can cause UAF. Therefore, to prevent this, error timer and urb must be killed before freeing the heap memory.

Risk And Classification

EPSS: 0.000440000 probability, percentile 0.137610000 (date 2026-06-04)

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 06513dd6d32c37d0364db8488cfdf3e14da238a8 e63f049c7764b615d1d50cb486745fa63372b42d git Not specified
CNA Linux Linux affected efaf61052b8ff9ee8968912fbaf02c2847c78ede e16985513e89466a236d2a7c202783b4dd0c5a46 git Not specified
CNA Linux Linux affected 647410a7da46067953a53c0d03f8680eff570959 dc4874366cf6cf4a31d8fa4b7f0e2a5b2d7647ba git Not specified
CNA Linux Linux affected c611b9e55174e439dcd85a72969b43a95f3827a4 647d6b8d22be12842fde6ed0c56859ebc615f21e git Not specified
CNA Linux Linux affected 0718a78f6a9f04b88d0dc9616cc216b31c5f3cf1 af600e7f5526d16146b3ae99f6ad57bfea79ca33 git Not specified
CNA Linux Linux affected 0718a78f6a9f04b88d0dc9616cc216b31c5f3cf1 353d8c715cc951a980728133c9dd64ca5a0a186c git Not specified
CNA Linux Linux affected 0718a78f6a9f04b88d0dc9616cc216b31c5f3cf1 9f2c0ac1423d5f267e7f1d1940780fc764b0fee3 git Not specified
CNA Linux Linux affected 62066758d2ae169278e5d6aea5995b1b6f6ddeb5 git Not specified
CNA Linux Linux affected 6.1.167 6.1.175 semver Not specified
CNA Linux Linux affected 6.15.3 6.16 semver Not specified
CNA Linux Linux affected 6.16 Not specified
CNA Linux Linux unaffected 6.16 semver Not specified
CNA Linux Linux unaffected 6.1.175 6.1.* semver Not specified
CNA Linux Linux unaffected 6.16.11 6.16.* semver Not specified
CNA Linux Linux unaffected 6.17.1 6.17.* semver Not specified
CNA Linux Linux unaffected 6.18 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/af600e7f5526d16146b3ae99f6ad57bfea79ca33 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/9f2c0ac1423d5f267e7f1d1940780fc764b0fee3 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/647d6b8d22be12842fde6ed0c56859ebc615f21e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/e16985513e89466a236d2a7c202783b4dd0c5a46 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/e63f049c7764b615d1d50cb486745fa63372b42d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/353d8c715cc951a980728133c9dd64ca5a0a186c 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/dc4874366cf6cf4a31d8fa4b7f0e2a5b2d7647ba 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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