CVE-2026-90220
Full vulnerability record from the local CVENow database.
Description
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.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-17 17:17:17.440000
Last modified
2026-10-30 13:20:46.793000
View original CVE JSON
{
"id": "CVE-2026-90220",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-17T17:17:17.440",
"lastModified": "2026-10-30T13:20:46.793",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Don't leak the extension cell pointer in the bounce payload\n\nThe bounce_error_event() embeds the failed event in the bounce payload\nby pointing data.ext.ptr at it. When that event is a queued\nvariable-length event, its own data.ext.ptr holds the address of its\nfirst extension cell, put there by snd_seq_event_dup(). The payload\ngoes out verbatim through snd_seq_expand_var_event(), so the address\nreaches userspace.\n\nThat is the same address commit 705dd6dcbc0e (\"ALSA: seq: Clear\nvariable event pointer on read\") removed from the event header. The\nread path still clears it there, just above the call that expands the\npayload.\n\nEmbed a sanitised copy instead, treated exactly as snd_seq_read()\ntreats the header. A stack copy is enough because delivery is\nsynchronous and snd_seq_event_dup() copies before returning.\n\nAn unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE,\nqueueing a variable-length event to a port that does not exist and\nreading the bounce back. Eight bytes on 64-bit, from its own pool."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"sound/core/seq/seq_clientmgr.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "05e2358fec8812c37516ccea63bc4b9956d864ba",
"lessThan": "c92b2e6e418a3885758438dddcead6e954a9e095",
"versionType": "git",
"status": "affected"
},
{
"version": "93d260ce43a81df579c98bee92b91316df9c1c57",
"lessThan": "42c3f856d13a91a0d4c302a0c6854813621136db",
"versionType": "git",
"status": "affected"
},
{
"version": "dae23c545eb5a2be3b27a82fd0f611894fb8ab69",
"lessThan": "b1e8d40663997aacaa198f37ce6893e07aaba77a",
"versionType": "git",
"status": "affected"
},
{
"version": "efc86691e4d8083d9e380ea95042c2cf679f65fd",
"lessThan": "6e6e471eef1d5d8cb056c7d364023fe048249204",
"versionType": "git",
"status": "affected"
},
{
"version": "efc86691e4d8083d9e380ea95042c2cf679f65fd",
"lessThan": "59e1592d3c270ff4642d5d6dc55c545306eb0693",
"versionType": "git",
"status": "affected"
},
{
"version": "eae296065ede41a24040e6a7c909ec970f78b4eb",
"versionType": "git",
"status": "affected"
},
{
"version": "0527a56cb327021cb73167cfddf0e49efa043500",
"versionType": "git",
"status": "affected"
},
{
"version": "6.12.97",
"lessThan": "6.12.110",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.18.40",
"lessThan": "6.18.52",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.6.160",
"lessThan": "6.7",
"versionType": "semver",
"status": "affected"
},
{
"version": "7.1.5",
"lessThan": "7.2",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"sound/core/seq/seq_clientmgr.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "7.2",
"status": "affected"
},
{
"version": "0",
"lessThan": "7.2",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.110",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.52",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.6",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/42c3f856d13a91a0d4c302a0c6854813621136db",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/59e1592d3c270ff4642d5d6dc55c545306eb0693",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6e6e471eef1d5d8cb056c7d364023fe048249204",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b1e8d40663997aacaa198f37ce6893e07aaba77a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c92b2e6e418a3885758438dddcead6e954a9e095",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}