CVE-2026-74339

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Clear variable event pointer on read snd_seq_read() copies a queued variable-length event header to userspace before expanding the payload. Queued variable-length events use SNDRV_SEQ_EXT_CHAINED internally, and data.ext.ptr points at the first extension cell. The read side strips SNDRV_SEQ_EXT_* bits from data.ext.len before the copy, but it leaves data.ext.ptr untouched. A userspace sequencer client can therefore write a direct variable event to itself and read back the extension-cell kernel address from the returned header. Clear the temporary header pointer before copy_to_user(). The original queued event remains unchanged and is still passed to snd_seq_expand_var_event(), so payload expansion keeps using the internal chain.

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/14fe4f75fd5309d6b75f8e840ada88912b374207
https://git.kernel.org/stable/c/6b52211eba213c461f68922708a99d8190c1fcd5
https://git.kernel.org/stable/c/705dd6dcbc0ea87351c660c1a6443f85f1001c76
https://git.kernel.org/stable/c/74ac1ce1f4afdb3b80b6742fa28fb86c8c51d31b
https://git.kernel.org/stable/c/c2ac9287e89916da684c2a548798351e63eb59ee
https://git.kernel.org/stable/c/e0c3edd86414534cfd179fefe45b38c29c01ae7a
https://git.kernel.org/stable/c/f29243c211928114f8b906e0a3fee77c236f14c8

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-15 06:22

Updated : 2026-08-17 06:19

NVD link : CVE-2026-74339

Mitre link : CVE-2026-74339

CVE.ORG link : CVE-2026-74339

JSON object : View

Products Affected

No product.

CWE

No CWE.

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