diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2017-10-27 22:19:26 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-17 09:38:54 +0100 |
| commit | 60c7a9cd5050378a7bfe385dc5feef9d406f22e1 (patch) | |
| tree | 8ad5b179707b9b53d8ef90fc73d4c6807861927b /include/target | |
| parent | 748e1b6281f5128c5ef8f9296761a232558c20d8 (diff) | |
target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK
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>
Diffstat (limited to 'include/target')
| -rw-r--r-- | include/target/target_core_base.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index eb3b23b6ec54..30f99ce4c6ce 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -493,6 +493,7 @@ 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; |