The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From ae072726f6109bb1c94841d6fb3a82dde298ea85 Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger nab@linux-iscsi.org Date: Fri, 27 Oct 2017 12:32:59 -0700 Subject: [PATCH] iscsi-target: Make TASK_REASSIGN use proper se_cmd->cmd_kref
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 dew@datera.io Cc: Donald White dew@datera.io 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
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 541f66a875fc..048d4227327c 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -1955,7 +1955,6 @@ iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd, 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; @@ -1988,22 +1987,23 @@ iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
cmd->data_direction = DMA_NONE; cmd->tmr_req = kzalloc(sizeof(*cmd->tmr_req), GFP_KERNEL); - if (!cmd->tmr_req) + if (!cmd->tmr_req) { return iscsit_add_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf); + } + + transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops, + conn->sess->se_sess, 0, DMA_NONE, + TCM_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, &iscsi_ops, - conn->sess->se_sess, 0, DMA_NONE, - TCM_SIMPLE_TAG, cmd->sense_buffer + 2); - - target_get_sess_cmd(&cmd->se_cmd, true); - sess_ref = true; tcm_function = iscsit_convert_tmf(function); if (tcm_function == TMR_UNKNOWN) { pr_err("Unknown iSCSI TMR Function:" @@ -2119,12 +2119,8 @@ iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd, * 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);