Patch "target/iscsi: Fix a race condition in iscsit_add_reject_from_cmd()" has been added to the 4.4-stable tree

Patch "target/iscsi: Fix a race condition in iscsit_add_reject_from_cmd()" 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/iscsi: Fix a race condition in iscsit_add_reject_from_cmd()

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-iscsi-fix-a-race-condition-in-iscsit_add_reject_from_cmd.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 foo@baz Mon Dec 18 14:47:43 CET 2017
From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Tue, 31 Oct 2017 11:03:17 -0700
Subject: target/iscsi: Fix a race condition in iscsit_add_reject_from_cmd()

From: Bart Van Assche <bart.vanassche@wdc.com>


[ Upstream commit cfe2b621bb18d86e93271febf8c6e37622da2d14 ]

Avoid that cmd->se_cmd.se_tfo is read after a command has already been
freed.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/target/iscsi/iscsi_target.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -674,6 +674,7 @@ static int iscsit_add_reject_from_cmd(
 	unsigned char *buf)
 {
 	struct iscsi_conn *conn;
+	const bool do_put = cmd->se_cmd.se_tfo != NULL;
 
 	if (!cmd->conn) {
 		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
@@ -704,7 +705,7 @@ static int iscsit_add_reject_from_cmd(
 	 * Perform the kref_put now if se_cmd has already been setup by
 	 * scsit_setup_scsi_cmd()
 	 */
-	if (cmd->se_cmd.se_tfo != NULL) {
+	if (do_put) {
 		pr_debug("iscsi reject: calling target_put_sess_cmd >>>>>>\n");
 		target_put_sess_cmd(&cmd->se_cmd);
 	}


Patches currently in stable-queue which might be from bart.vanassche@wdc.com are

queue-4.4/target-iscsi-fix-a-race-condition-in-iscsit_add_reject_from_cmd.patch
queue-4.4/rdma-cma-avoid-triggering-undefined-behavior.patch