scsi: core: Do not block on tag allocation in scsi_eh_lock_door()
In the Linux kernel, the following vulnerability has been resolved: scsi: core: Do not block on tag allocation in scsi_eh_lock_door() scsi_eh_lock_door() is called from scsi_restart_operations() while the host is still in the SHOST_RECOVERY state, i.e. before the host is switched back to SHOST_RUNNING and scsi_run_host_queues() restarts the queues. It allocates a request via scsi_alloc_request() with no flags, so blk_mq_get_tag() may block waiting for a free sched tag when all tags are already in use. Those tags can be held by commands that were just requeued by scsi_eh_flush_done_q() during error handling. Such commands cannot be dispatched until the host leaves SHOST_RECOVERY and scsi_run_host_queues() is called - which only happens *after* scsi_eh_lock_door() returns. This forms a circular dependency: - scsi_eh_lock_door(), running in the SCSI error handler thread, waits for a sched tag held by a requeued command; - the requeued command cannot complete and release its sched tag until the error handler thread leaves scsi_restart_operations() and restart the queues. For devices with a single driver tag (e.g. USB storage) it is a guaranteed deadlock and I/O that can never be submitted. This problem has also been reproduced in our environment. Locking the door is a best-effort operation, and scsi_eh_lock_door() already returns silently when the request allocation fails. Pass BLK_MQ_REQ_NOWAIT to scsi_alloc_request() so the allocation fails instead of blocking when no tag is av
CVE-2026-93781
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-93781
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6e68af666f5336254b5715dca591026b7324499a",
"lessThan": "3bc7af4cefac1c583f0607f6183a67012436aad9",
"versionType": "git"
},
{
"status": "affected",
"version": "6e68af666f5336254b5715dca591026b7324499a",
"lessThan": "6b450c277c106c4e31411067f025d1aaa27c2a02",
"versionType": "git"
},
{
"status": "affected",
"version": "6e68af666f5336254b5715dca591026b7324499a",
"lessThan": "261c80a6b23e34ba98bcf3f75317e35ecf0a08f0",
"versionType": "git"
},
{
"status": "affected",
"version": "6e68af666f5336254b5715dca591026b7324499a",
"lessThan": "dc9e1b6b9080dd6374cc9a38e4b53abca63c3b1b",
"versionType": "git"
},
{
"status": "affected",
"version": "6e68af666f5336254b5715dca591026b7324499a",
"lessThan": "732cb6bb37fd26863d5786522fb1997e7f5865b4",
"versionType": "git"
}
],
"programFiles": [
"drivers/scsi/scsi_error.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/scsi/scsi_error.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-93781
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #8258 · Revision 1
- Added to Heist Feed
- Publisher date