Commit 9d7464b1 authored by Dan Carpenter's avatar Dan Carpenter Committed by Martin K. Petersen
Browse files

scsi: target: tcmu: Fix a use after free in tcmu_check_expired_queue_cmd() 

The pr_debug() dereferences "cmd" after we already freed it by calling
tcmu_free_cmd(cmd).  The debug printk needs to be done earlier.

Link: https://lore.kernel.org/r/20200523101129.GB98132@mwanda


Fixes: 61fb2482 ("scsi: target: tcmu: Userspace must not complete queued commands")
Reviewed-by: default avatarMike Christie <mchristi@redhat.com>
Reviewed-by: default avatarDavid Disseldorp <ddiss@suse.de>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 5ae6a6a9

drivers/target/target_core_user.c

+3 −3
Original line number Diff line number Diff line
@@ -1292,13 +1292,13 @@ static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd) 
	if (!time_after(jiffies, cmd->deadline))

		return;



	pr_debug("Timing out queued cmd %p on dev %s.\n",

		  cmd, cmd->tcmu_dev->name);



	list_del_init(&cmd->queue_entry);

	se_cmd = cmd->se_cmd;

	tcmu_free_cmd(cmd);



	pr_debug("Timing out queued cmd %p on dev %s.\n",

		  cmd, cmd->tcmu_dev->name);



	target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);

}