[PATCH 3.16 066/136] iscsi-target: Fix non-immediate TMR reference leak

[Ben Hutchings]

3.16.54-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

commit 3fc9fb13a4b2576aeab86c62fd64eb29ab68659c upstream.

This patch fixes a se_cmd->cmd_kref reference leak that can
occur when a non immediate TMR is proceeded our of command
sequence number order, and CMDSN_LOWER_THAN_EXP is returned
by iscsit_sequence_cmd().

To address this bug, call target_put_sess_cmd() during this
special case following what iscsit_process_scsi_cmd() does
upon CMDSN_LOWER_THAN_EXP.

Cc: Mike Christie <mchristi@xxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
[bwh: Backported to 3.16: target_put_sess_cmd() takes an se_session pointer
 too]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/target/iscsi/iscsi_target.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1917,12 +1917,14 @@ attach:
 
 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 		int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
-		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP)
+		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP) {
 			out_of_order_cmdsn = 1;
-		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
+		} else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
+			target_put_sess_cmd(conn->sess->se_sess, &cmd->se_cmd);
 			return 0;
-		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
+		} else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER) {
 			return -1;
+		}
 	}
 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));