Patch "target: Drop incorrect ABORT_TASK put for completed commands" has been added to the 4.4-stable tree

Patch "target: Drop incorrect ABORT_TASK put for completed commands" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    target: Drop incorrect ABORT_TASK put for completed commands

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     target-drop-incorrect-abort_task-put-for-completed-commands.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 7f54ab5ff52fb0b91569bc69c4a6bc5cac1b768d Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Sat, 5 Mar 2016 20:00:12 -0800
Subject: target: Drop incorrect ABORT_TASK put for completed commands

From: Nicholas Bellinger <nab@linux-iscsi.org>

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>

---
 drivers/target/target_core_tmr.c |    1 -
 1 file changed, 1 deletion(-)

--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -177,7 +177,6 @@ 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_cmd);
 			goto out;
 		}
 		list_del_init(&se_cmd->se_cmd_list);


Patches currently in stable-queue which might be from nab@linux-iscsi.org are

queue-4.4/target-drop-incorrect-abort_task-put-for-completed-commands.patch