[3.13.y-ckt stable] Patch "target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt27.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 0bea77a8d70856009cef7ba7304ce52d5dd4117a Mon Sep 17 00:00:00 2001
From: Alexei Potashnik <alexei at purestorage.com>
Date: Tue, 21 Jul 2015 15:07:56 -0700
Subject: target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT

commit 9547308bda296b6f69876c840a0291fcfbeddbb8 upstream.

Make sure all non-READ SCSI commands get targ_xfer_tag initialized
to 0xffffffff, not just WRITEs.

Double-free of a TUR cmd object occurs under the following scenario:

1. TUR received (targ_xfer_tag is uninitialized and left at 0)
2. TUR status sent
3. First unsolicited NOPIN is sent to initiator (gets targ_xfer_tag of 0)
4. NOPOUT for NOPIN (with TTT=0) arrives
 - its ExpStatSN acks TUR status, TUR is queued for removal
 - LIO tries to find NOPIN with TTT=0, but finds the same TUR instead,
   TUR is queued for removal for the 2nd time

(Drop unbalanced conditional bracket usage - nab)

Signed-off-by: Alexei Potashnik <alexei at purestorage.com>
Signed-off-by: Spencer Baugh <sbaugh at catern.com>
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
[ luis: backported to 3.16:
  - kept brackets as they are needed in 3.16 kernel ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/target/iscsi/iscsi_target.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 931833f..effc8c7 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -946,7 +946,7 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
 		if (cmd->targ_xfer_tag == 0xFFFFFFFF)
 			cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
 		spin_unlock_bh(&conn->sess->ttt_lock);
-	} else if (hdr->flags & ISCSI_FLAG_CMD_WRITE)
+	} else
 		cmd->targ_xfer_tag = 0xFFFFFFFF;
 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
--
1.9.1