CVE-2026-93781

CVE CVE-2026-93781EUVD EUVD-2026-86168Veröffentlicht 2026-09-24T16:02:13.000ZZuletzt geändert 2026-09-25T12:42:46.000Z

Was das Advisory beschreibt

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 available. This breaks the circular dependency and allows the error handler to finish restarting the queues, after which the pending commands are dispatched normally.

Quelle: EUVD (ENISA), im Wortlaut der Meldung.

Produkte, die das Advisory nennt

Diese Angaben stammen aus der Meldung selbst, nicht aus einer Prüfung durch uns.

• Linux — Linux 2.6.16; 6e68af666f5336254b5715dca591026b7324499a <dc9e1b6b9080dd6374cc9a38e4b53abca63c3b1b; 6e68af666f5336254b5715dca591026b7324499a <732cb6bb37fd26863d5786522fb1997e7f5865b4; patch: 6.18.53; patch: 7.2; 6e68af666f5336254b5715dca591026b7324499a <261c80a6b23e34ba98bcf3f75317e35ecf0a08f0; patch: 0; patch: 6.12.111

Die genannten Versionen sind die Angabe der Meldung. Patchlage vergleicht keine Versionsnummern und leitet aus ihnen keine Aussage ab — welche Version installiert ist, muss ein Mensch nachsehen.

Im Produktkatalog geführt

Für diese Produkte kann ein Bestand in Patchlage erfasst werden. Ein Advisory dazu erscheint am Morgen danach im Lagebericht.

• Linux — Linux

Patchlage meldet Treffer und Verdachtsfälle. Zu allem anderen sagt dieses System nichts — weder diese Seite noch der Lagebericht behauptet je, dass ein Bestand sicher ist.