Description
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.
Metrics
No CVSS score has been published yet.
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 8a631e1aaa1ebbc9de916927fa01707244e18291; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 14fe4f75fd5309d6b75f8e840ada88912b374207; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < f29243c211928114f8b906e0a3fee77c236f14c8; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < e0c3edd86414534cfd179fefe45b38c29c01ae7a; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 6b52211eba213c461f68922708a99d8190c1fcd5; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 74ac1ce1f4afdb3b80b6742fa28fb86c8c51d31b; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < c2ac9287e89916da684c2a548798351e63eb59ee; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 705dd6dcbc0ea87351c660c1a6443f85f1001c76 |
| Linux | Linux | 2.6.12 |
References
- 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/8a631e1aaa1ebbc9de916927fa01707244e18291
- https://git.kernel.org/stable/c/c2ac9287e89916da684c2a548798351e63eb59ee
- https://git.kernel.org/stable/c/e0c3edd86414534cfd179fefe45b38c29c01ae7a
- https://git.kernel.org/stable/c/f29243c211928114f8b906e0a3fee77c236f14c8
Timeline
- Published
- Aug 15, 2026
- Last modified
- Nov 6, 2026
- NVD status
- Received