iscsi-target: Fix non-immediate TMR reference leak

[ Upstream commit 3fc9fb13a4b2576aeab86c62fd64eb29ab68659c ]

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@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 89d01943ca9381b4c95db5c65ef3ee79e1f37c50..8df1ff3766c414925d3581d20d97fefd0ebac83a 100644 (file)
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1919,12 +1919,14 @@ 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(&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));