--- /dev/null
+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: iscsi-target: Make TASK_REASSIGN use proper se_cmd->cmd_kref
+
+From: Nicholas Bellinger <nab@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 <dew@datera.io>
+Cc: Donald White <dew@datera.io>
+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 | 20 +++++++-------------
+ 1 file changed, 7 insertions(+), 13 deletions(-)
+
+--- a/drivers/target/iscsi/iscsi_target.c
++++ b/drivers/target/iscsi/iscsi_target.c
+@@ -1759,7 +1759,6 @@ 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;
+@@ -1801,18 +1800,17 @@ iscsit_handle_task_mgt_cmd(struct iscsi_
+ 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;
+-
+ switch (function) {
+ case ISCSI_TM_FUNC_ABORT_TASK:
+ tcm_function = TMR_ABORT_TASK;
+@@ -1951,12 +1949,8 @@ 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);
--- /dev/null
+From 1c21a48055a67ceb693e9c2587824a8de60a217c Mon Sep 17 00:00:00 2001
+From: Nicholas Bellinger <nab@linux-iscsi.org>
+Date: Fri, 27 Oct 2017 22:19:26 -0800
+Subject: target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK
+
+From: Nicholas Bellinger <nab@linux-iscsi.org>
+
+commit 1c21a48055a67ceb693e9c2587824a8de60a217c upstream.
+
+This patch fixes bug where early se_cmd exceptions that occur
+before backend execution can result in use-after-free if/when
+a subsequent ABORT_TASK occurs for the same tag.
+
+Since an early se_cmd exception will have had se_cmd added to
+se_session->sess_cmd_list via target_get_sess_cmd(), it will
+not have CMD_T_COMPLETE set by the usual target_complete_cmd()
+backend completion path.
+
+This causes a subsequent ABORT_TASK + __target_check_io_state()
+to signal ABORT_TASK should proceed. As core_tmr_abort_task()
+executes, it will bring the outstanding se_cmd->cmd_kref count
+down to zero releasing se_cmd, after se_cmd has already been
+queued with error status into fabric driver response path code.
+
+To address this bug, introduce a CMD_T_PRE_EXECUTE bit that is
+set at target_get_sess_cmd() time, and cleared immediately before
+backend driver dispatch in target_execute_cmd() once CMD_T_ACTIVE
+is set.
+
+Then, check CMD_T_PRE_EXECUTE within __target_check_io_state() to
+determine when an early exception has occured, and avoid aborting
+this se_cmd since it will have already been queued into fabric
+driver response path 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>
+Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ drivers/target/target_core_tmr.c | 9 +++++++++
+ drivers/target/target_core_transport.c | 2 ++
+ include/target/target_core_base.h | 1 +
+ 3 files changed, 12 insertions(+)
+
+--- a/drivers/target/target_core_tmr.c
++++ b/drivers/target/target_core_tmr.c
+@@ -133,6 +133,15 @@ static bool __target_check_io_state(stru
+ spin_unlock(&se_cmd->t_state_lock);
+ return false;
+ }
++ if (se_cmd->transport_state & CMD_T_PRE_EXECUTE) {
++ if (se_cmd->scsi_status) {
++ pr_debug("Attempted to abort io tag: %llu early failure"
++ " status: 0x%02x\n", se_cmd->tag,
++ se_cmd->scsi_status);
++ spin_unlock(&se_cmd->t_state_lock);
++ return false;
++ }
++ }
+ if (sess->sess_tearing_down || se_cmd->cmd_wait_set) {
+ pr_debug("Attempted to abort io tag: %llu already shutdown,"
+ " skipping\n", se_cmd->tag);
+--- a/drivers/target/target_core_transport.c
++++ b/drivers/target/target_core_transport.c
+@@ -1933,6 +1933,7 @@ void target_execute_cmd(struct se_cmd *c
+ }
+
+ cmd->t_state = TRANSPORT_PROCESSING;
++ cmd->transport_state &= ~CMD_T_PRE_EXECUTE;
+ cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
+ spin_unlock_irq(&cmd->t_state_lock);
+
+@@ -2572,6 +2573,7 @@ int target_get_sess_cmd(struct se_cmd *s
+ ret = -ESHUTDOWN;
+ goto out;
+ }
++ se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
+ list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
+ out:
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+--- a/include/target/target_core_base.h
++++ b/include/target/target_core_base.h
+@@ -496,6 +496,7 @@ struct se_cmd {
+ #define CMD_T_BUSY (1 << 9)
+ #define CMD_T_TAS (1 << 10)
+ #define CMD_T_FABRIC_STOP (1 << 11)
++#define CMD_T_PRE_EXECUTE (1 << 12)
+ spinlock_t t_state_lock;
+ struct kref cmd_kref;
+ struct completion t_transport_stop_comp;
projects / thirdparty / kernel / stable-queue.git / commitdiff
