From: Tejun Heo <[email protected]> ===================================================================== | This is a commit scheduled for the next v2.6.34 longterm release. | | If you see a problem with using this for longterm, please comment.| =====================================================================
commit 2a5f07b5ec098edc69e05fdd2f35d3fbb1235723 upstream. 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 <[email protected]> Signed-off-by: Jeff Garzik <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- drivers/ata/libata-scsi.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 0088cde..1d266e2 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -2548,8 +2548,11 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc) * * If door lock fails, always clear sdev->locked to * avoid this infinite loop. + * + * This may happen before SCSI scan is complete. Make + * sure qc->dev->sdev isn't NULL before dereferencing. */ - if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL) + if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL && qc->dev->sdev) qc->dev->sdev->locked = 0; qc->scsicmd->result = SAM_STAT_CHECK_CONDITION; -- 1.7.4.4 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
