[PATCH 4.4 40/96] iscsi-target: Fix non-immediate TMR reference leak

Greg Kroah-Hartman
2017-11-28T10:29:48Z

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

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@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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
@@ -1923,12 +1923,14 @@ 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));