ALSA: seq: Clear variable event pointer on read
Summary
| CVE | CVE-2026-74339 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-15 06:22:34 UTC |
| Updated | 2026-08-17 06:19:28 UTC |
| 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. |
Risk And Classification
EPSS: 0.001720000 probability, percentile 0.069580000 (date 2026-08-16)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 14fe4f75fd5309d6b75f8e840ada88912b374207 git | Not specified |
| CNA | Linux | Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 f29243c211928114f8b906e0a3fee77c236f14c8 git | Not specified |
| CNA | Linux | Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 e0c3edd86414534cfd179fefe45b38c29c01ae7a git | Not specified |
| CNA | Linux | Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 6b52211eba213c461f68922708a99d8190c1fcd5 git | Not specified |
| CNA | Linux | Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 74ac1ce1f4afdb3b80b6742fa28fb86c8c51d31b git | Not specified |
| CNA | Linux | Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 c2ac9287e89916da684c2a548798351e63eb59ee git | Not specified |
| CNA | Linux | Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 705dd6dcbc0ea87351c660c1a6443f85f1001c76 git | Not specified |
| CNA | Linux | Linux | affected 2.6.12 | Not specified |
| CNA | Linux | Linux | unaffected 2.6.12 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.212 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.178 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.145 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.97 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.40 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.5 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/e0c3edd86414534cfd179fefe45b38c29c01ae7a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/f29243c211928114f8b906e0a3fee77c236f14c8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/74ac1ce1f4afdb3b80b6742fa28fb86c8c51d31b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/c2ac9287e89916da684c2a548798351e63eb59ee | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/6b52211eba213c461f68922708a99d8190c1fcd5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/705dd6dcbc0ea87351c660c1a6443f85f1001c76 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/14fe4f75fd5309d6b75f8e840ada88912b374207 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.