3.18-stable review patch.  If anyone has any objections, please let me know.

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

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

commit ae072726f6109bb1c94841d6fb3a82dde298ea85 upstream.

Since commit 59b6986dbf fixed a potential NULL pointer dereference
by allocating a se_tmr_req for ISCSI_TM_FUNC_TASK_REASSIGN, the
se_tmr_req is currently leaked by iscsit_free_cmd() because no
iscsi_cmd->se_cmd.se_tfo was associated.

To address this, treat ISCSI_TM_FUNC_TASK_REASSIGN like any other
TMR and call transport_init_se_cmd() + target_get_sess_cmd() to
setup iscsi_cmd->se_cmd.se_tfo with se_cmd->cmd_kref of 2.

This will ensure normal release operation once se_cmd->cmd_kref
reaches zero and target_release_cmd_kref() is invoked, se_tmr_req
will be released via existing target_free_cmd_mem() and
core_tmr_release_req() code.

Reported-by: Donald White <d...@datera.io>
Cc: Donald White <d...@datera.io>
Cc: Mike Christie <mchri...@redhat.com>
Cc: Hannes Reinecke <h...@suse.com>
Signed-off-by: Nicholas Bellinger <n...@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>


---
 drivers/target/iscsi/iscsi_target.c |   21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1750,7 +1750,6 @@ iscsit_handle_task_mgt_cmd(struct iscsi_
        struct iscsi_tmr_req *tmr_req;
        struct iscsi_tm *hdr;
        int out_of_order_cmdsn = 0, ret;
-       bool sess_ref = false;
        u8 function, tcm_function = TMR_UNKNOWN;
 
        hdr                     = (struct iscsi_tm *) buf;
@@ -1792,19 +1791,17 @@ iscsit_handle_task_mgt_cmd(struct iscsi_
                                             buf);
        }
 
+       transport_init_se_cmd(&cmd->se_cmd, &lio_target_fabric_configfs->tf_ops,
+                             conn->sess->se_sess, 0, DMA_NONE,
+                             MSG_SIMPLE_TAG, cmd->sense_buffer + 2);
+
+       target_get_sess_cmd(&cmd->se_cmd, true);
+
        /*
         * TASK_REASSIGN for ERL=2 / connection stays inside of
         * LIO-Target $FABRIC_MOD
         */
        if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
-               transport_init_se_cmd(&cmd->se_cmd,
-                                     &lio_target_fabric_configfs->tf_ops,
-                                     conn->sess->se_sess, 0, DMA_NONE,
-                                     MSG_SIMPLE_TAG, cmd->sense_buffer + 2);
-
-               target_get_sess_cmd(&cmd->se_cmd, true);
-               sess_ref = true;
-
                switch (function) {
                case ISCSI_TM_FUNC_ABORT_TASK:
                        tcm_function = TMR_ABORT_TASK;
@@ -1943,12 +1940,8 @@ 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(&cmd->se_cmd);
-       }
-
        iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
+       target_put_sess_cmd(&cmd->se_cmd);
        return 0;
 }
 EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);


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