target: Fix reference leak in target_get_sess_cmd() error path

[ Upstream commit 7544e597343e2166daba3f32e4708533aa53c233 ]

This patch fixes a se_cmd->cmd_kref leak buf when se_sess->sess_tearing_down
is true within target_get_sess_cmd() submission path code.

This se_cmd reference leak can occur during active session shutdown when
ack_kref=1 is passed by target_submit_cmd_[map_sgls,tmr]() callers.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: <stable@vger.kernel.org> # 3.6+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index be877bf6f7304a88fabb3506d65ac75542471b01..2e0998420254ffdbede0b1ae60fe97f3670ec635 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2389,6 +2389,10 @@ int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
        list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
 out:
        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+       if (ret && ack_kref)
+               target_put_sess_cmd(se_sess, se_cmd);
+
        return ret;
 }
 EXPORT_SYMBOL(target_get_sess_cmd);