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scsi: mvsas: Fix use-after-free bugs in mvs_work_queue

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During the detaching of Marvell's SAS/SATA controller, the original code
calls cancel_delayed_work() in mvs_free() to cancel the delayed work
item mwq->work_q. However, if mwq->work_q is already running, the
cancel_delayed_work() may fail to cancel it. This can lead to
use-after-free scenarios where mvs_free() frees the mvs_info while
mvs_work_queue() is still executing and attempts to access the
already-freed mvs_info.

A typical race condition is illustrated below:

CPU 0 (remove)            | CPU 1 (delayed work callback)
mvs_pci_remove()          |
  mvs_free()              | mvs_work_queue()
    cancel_delayed_work() |
      kfree(mvi)          |
                          |   mvi-> // UAF

Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the delayed work item is properly canceled and any executing
delayed work item completes before the mvs_info is deallocated.

This bug was found by static analysis.

Fixes: 20b09c2992fe ("[SCSI] mvsas: add support for 94xx; layout change; bug fixes")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Duoming Zhou 2025-09-20 21:42:01 +08:00 committed by Martin K. Petersen
parent 0ba7a254af
commit 60cd16a3b7
1 changed files with 1 additions and 1 deletions
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2
drivers/scsi/mvsas/mv_init.c
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@ -124,7 +124,7 @@ static void mvs_free(struct mvs_info *mvi)
if (mvi->shost)
scsi_host_put(mvi->shost);
list_for_each_entry(mwq, &mvi->wq_list, entry)
cancel_delayed_work(&mwq->work_q);
cancel_delayed_work_sync(&mwq->work_q);
kfree(mvi->rsvd_tags);
kfree(mvi);
}