iscsi-target: Fix ISCSI_OP_SCSI_TMFUNC handling for iser

This patch adds target_get_sess_cmd reference counting for
iscsit_handle_task_mgt_cmd(), and adds a target_put_sess_cmd()
for the failure case.

It also fixes a bug where ISCSI_OP_SCSI_TMFUNC type commands
where leaking iscsi_cmd->i_conn_node and eventually triggering
an OOPs during struct isert_conn shutdown.

Cc: stable@vger.kernel.org  # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 4319dad7d919..c30ec1d5756e 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1737,8 +1737,8 @@ iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
         struct se_tmr_req *se_tmr;
         struct iscsi_tmr_req *tmr_req;
         struct iscsi_tm *hdr;
-        int out_of_order_cmdsn = 0;
-        int ret;
+        int out_of_order_cmdsn = 0, ret;
+        bool sess_ref = false;
         u8 function;
 
         hdr                     = (struct iscsi_tm *) buf;
@@ -1794,6 +1794,9 @@ iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
                                       conn->sess->se_sess, 0, DMA_NONE,
                                       MSG_SIMPLE_TAG, cmd->sense_buffer + 2);
 
+                target_get_sess_cmd(conn->sess->se_sess, &cmd->se_cmd, true);
+                sess_ref = true;
+
                 switch (function) {
                 case ISCSI_TM_FUNC_ABORT_TASK:
                         tcm_function = TMR_ABORT_TASK;
@@ -1931,6 +1934,11 @@ attach:
          * For connection recovery, this is also the default action for
          * TMR TASK_REASSIGN.
          */
+        if (sess_ref) {
+                pr_debug("Handle TMR, using sess_ref=true check\n");
+                target_put_sess_cmd(conn->sess->se_sess, &cmd->se_cmd);
+        }
+
         iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
         return 0;
 }