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

[ Upstream commit 9d7464b188 ]

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: 61fb248221 ("scsi: target: tcmu: Userspace must not complete queued commands")
Reviewed-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dan Carpenter 2020-05-23 13:11:29 +03:00 committed by Greg Kroah-Hartman
parent 87b3dca712
commit 41324c4830
1 changed files with 3 additions and 3 deletions

View File

@ -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);
}