scsi: tcmu: fix use after free

lxbsz · martinkpetersen · commit 40d883b09175 · 2019-01-22T20:54:00.000-05:00
Fixes: a94a257 ("scsi: tcmu: avoid cmd/qfull timers updated whenever a new cmd comes") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Mike Christie <mchristi@redhat.com> Signed-off-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
@@ -1317,12 +1317,13 @@ static int tcmu_check_expired_cmd(int id, void *p, void *data)
 		 * target_complete_cmd will translate this to LUN COMM FAILURE
 		 */
 		scsi_status = SAM_STAT_CHECK_CONDITION;
+		list_del_init(&cmd->queue_entry);
 	} else {
+		list_del_init(&cmd->queue_entry);
 		idr_remove(&udev->commands, id);
 		tcmu_free_cmd(cmd);
 		scsi_status = SAM_STAT_TASK_SET_FULL;
 	}
-	list_del_init(&cmd->queue_entry);
 
 	pr_debug("Timing out cmd %u on dev %s that is %s.\n",
 		 id, udev->name, is_running ? "inflight" : "queued");
