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authorEwan D. Milne <emilne@redhat.com>2012-11-02 13:38:34 (GMT)
committerJames Bottomley <JBottomley@Parallels.com>2013-07-23 14:41:53 (GMT)
commit085b513f97d8d799d28491239be4b451bcd8c2c5 (patch)
tree1f7e0786f3e7ccf24cc8f77077540ebf7285fbd7 /drivers/scsi
parentc3ccb1d7cf4c4549151876dd37c0944a682fd9e1 (diff)
downloadlinux-085b513f97d8d799d28491239be4b451bcd8c2c5.tar.xz
[SCSI] sd: fix crash when UA received on DIF enabled device
sd_prep_fn will allocate a larger CDB for the command via mempool_alloc for devices using DIF type 2 protection. This CDB was being freed in sd_done, which results in a kernel crash if the command is retried due to a UNIT ATTENTION. This change moves the code to free the larger CDB into sd_unprep_fn instead, which is invoked after the request is complete. It is no longer necessary to call scsi_print_command separately for this case as the ->cmnd will no longer be NULL in the normal code path. Also removed conditional test for DIF type 2 when freeing the larger CDB because the protection_type could have been changed via sysfs while the command was executing. Signed-off-by: Ewan D. Milne <emilne@redhat.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/sd.c22
1 files changed, 7 insertions, 15 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 80f39b8..86fcf2c 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -838,10 +838,17 @@ static int scsi_setup_flush_cmnd(struct scsi_device *sdp, struct request *rq)
static void sd_unprep_fn(struct request_queue *q, struct request *rq)
{
+ struct scsi_cmnd *SCpnt = rq->special;
+
if (rq->cmd_flags & REQ_DISCARD) {
free_page((unsigned long)rq->buffer);
rq->buffer = NULL;
}
+ if (SCpnt->cmnd != rq->cmd) {
+ mempool_free(SCpnt->cmnd, sd_cdb_pool);
+ SCpnt->cmnd = NULL;
+ SCpnt->cmd_len = 0;
+ }
}
/**
@@ -1720,21 +1727,6 @@ static int sd_done(struct scsi_cmnd *SCpnt)
if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
sd_dif_complete(SCpnt, good_bytes);
- if (scsi_host_dif_capable(sdkp->device->host, sdkp->protection_type)
- == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd) {
-
- /* We have to print a failed command here as the
- * extended CDB gets freed before scsi_io_completion()
- * is called.
- */
- if (result)
- scsi_print_command(SCpnt);
-
- mempool_free(SCpnt->cmnd, sd_cdb_pool);
- SCpnt->cmnd = NULL;
- SCpnt->cmd_len = 0;
- }
-
return good_bytes;
}