aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/ata
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2010-11-01 06:39:19 -0400
committerJeff Garzik <jgarzik@redhat.com>2010-11-12 17:10:51 -0500
commit2a5f07b5ec098edc69e05fdd2f35d3fbb1235723 (patch)
tree28180df99e2b236018c29dd05480b13024159868 /drivers/ata
parenta0a6da1a735ba66c04019b39cca8f79008d6c434 (diff)
libata: fix NULL sdev dereference race in atapi_qc_complete()
SCSI commands may be issued between __scsi_add_device() and dev->sdev assignment, so it's unsafe for ata_qc_complete() to dereference dev->sdev->locked without checking whether it's NULL or not. Fix it. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libata-scsi.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index d050e073e570..3f91c01c217f 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2552,8 +2552,11 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
2552 * 2552 *
2553 * If door lock fails, always clear sdev->locked to 2553 * If door lock fails, always clear sdev->locked to
2554 * avoid this infinite loop. 2554 * avoid this infinite loop.
2555 *
2556 * This may happen before SCSI scan is complete. Make
2557 * sure qc->dev->sdev isn't NULL before dereferencing.
2555 */ 2558 */
2556 if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL) 2559 if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL && qc->dev->sdev)
2557 qc->dev->sdev->locked = 0; 2560 qc->dev->sdev->locked = 0;
2558 2561
2559 qc->scsicmd->result = SAM_STAT_CHECK_CONDITION; 2562 qc->scsicmd->result = SAM_STAT_CHECK_CONDITION;