Bug 2517018 (CVE-2026-74502) - CVE-2026-74502 kernel: ALSA: ump: fix double free of out_cvts on rawmidi error
Summary: CVE-2026-74502 kernel: ALSA: ump: fix double free of out_cvts on rawmidi error
Keywords:
Status: NEW
Alias: CVE-2026-74502
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 12:45 UTC by OSIDB Bzimport
Modified: 2026-08-21 08:33 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-08-15 12:45:05 UTC
In the Linux kernel, the following vulnerability has been resolved:

ALSA: ump: fix double free of out_cvts on rawmidi error

snd_ump_attach_legacy_rawmidi() allocates the legacy conversion array
ump->out_cvts and, on the snd_rawmidi_new() error path, frees it with
kfree() but leaves ump->out_cvts pointing at the freed memory.  When the
endpoint is later torn down, snd_ump_endpoint_free() frees ump->out_cvts
a second time, resulting in a double free.

The host snd-usb-audio driver attaches the legacy rawmidi for any USB
MIDI 2.0 (UMP) device, so a device that makes snd_rawmidi_new() fail
reaches this path on enumeration.

Clear ump->out_cvts after freeing it on the error path so it is not
freed again during teardown.

Discovered by XBOW, triaged by Baul Lee <baul.lee>

Comment 1 Mauro Matteo Cascella 2026-08-21 08:27:44 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081541-CVE-2026-74502-5720@gregkh/T


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