In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: Don't leak the extension cell pointer in the bounce payload
The bounce_error_event() embeds the failed event in the bounce payload
by pointing data.ext.ptr at it. When that event is a queued
variable-length event, its own data.ext.ptr holds the address of its
first extension cell, put there by snd_seq_event_dup(). The payload
goes out verbatim through snd_seq_expand_var_event(), so the address
reaches userspace.
That is the same address commit 705dd6dcbc0e ("ALSA: seq: Clear
variable event pointer on read") removed from the event header. The
read path still clears it there, just above the call that expands the
payload.
Embed a sanitised copy instead, treated exactly as snd_seq_read()
treats the header. A stack copy is enough because delivery is
synchronous and snd_seq_event_dup() copies before returning.
An unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE,
queueing a variable-length event to a port that does not exist and
reading the bounce back. Eight bytes on 64-bit, from its own pool.
CVSS
No CVSS.
References
Configurations
No configuration.
History
17 Sep 2026, 17:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-09-17 17:17
Updated : 2026-09-17 17:17
NVD link : CVE-2026-90220
Mitre link : CVE-2026-90220
CVE.ORG link : CVE-2026-90220
JSON object : View
Products Affected
No product.
CWE
No CWE.