target: Drop incorrect ABORT_TASK put for completed commands

commit 7f54ab5ff52fb0b91569bc69c4a6bc5cac1b768d upstream.

This patch fixes a recent ABORT_TASK regression associated
with commit febe562c, where a left-over target_put_sess_cmd()
would still be called when __target_check_io_state() detected
a command has already been completed, and explicit ABORT must
be avoided.

Note commit febe562c dropped the local kref_get_unless_zero()
check in core_tmr_abort_task(), but did not drop this extra
corresponding target_put_sess_cmd() in the failure path.

So go ahead and drop this now bogus target_put_sess_cmd(),
and avoid this potential use-after-free.

Reported-by: Dan Lane <dracodan@gmail.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 47a90d631a90761aa86f5451ce464f11bd13b1b8..77c14385411886fa4f67e0a9cae978a0fc2b379a 100644 (file)
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -181,7 +181,6 @@ void core_tmr_abort_task(
 
                if (!__target_check_io_state(se_cmd, se_sess, 0)) {
                        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
-                       target_put_sess_cmd(se_sess, se_cmd);
                        goto out;
                }