scsi: tcmu: fix use after free

Fixes: a94a2572b977 ("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
index c34c88e..5831e0e 100644 (file)
--- 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");