[PATCH 4.19 70/90] scsi: tcmu: fix use after free

Greg Kroah-Hartman
2019-07-08T15:39:36Z

[ Upstream commit 40d883b091758472c79b81fa1c0e0347e24a9cff ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/target/target_core_user.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index ac7620120491..c46efa47d68a 100644
--- 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");
--
2.20.1