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author | Nicholas Bellinger <nab@linux-iscsi.org> | 2017-10-28 08:19:26 +0200 |
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committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2017-11-08 04:50:24 +0100 |
commit | 1c21a48055a67ceb693e9c2587824a8de60a217c (patch) | |
tree | 43fd75f6f3cfc05510242b7d9a40fa9740b9b18a /include/net | |
parent | target: Fix quiese during transport_write_pending_qf endless loop (diff) | |
download | linux-1c21a48055a67ceb693e9c2587824a8de60a217c.tar.xz linux-1c21a48055a67ceb693e9c2587824a8de60a217c.zip |
target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK
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>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/net')
0 files changed, 0 insertions, 0 deletions