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author | Nicholas Bellinger <nab@linux-iscsi.org> | 2017-03-23 17:19:24 -0700 |
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committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2017-03-30 01:36:51 -0700 |
commit | efb2ea770bb3b0f40007530bc8b0c22f36e1c5eb (patch) | |
tree | 503c3d80c8872dbf3a1f05bb767c2054c9a65573 /drivers/target/target_core_fabric_configfs.c | |
parent | afea03fcf3d5db8a968f4b97797b8b83ada0dba3 (diff) | |
download | linux-stable-efb2ea770bb3b0f40007530bc8b0c22f36e1c5eb.tar.gz linux-stable-efb2ea770bb3b0f40007530bc8b0c22f36e1c5eb.tar.bz2 linux-stable-efb2ea770bb3b0f40007530bc8b0c22f36e1c5eb.zip |
iscsi-target: Fix TMR reference leak during session shutdown
This patch fixes a iscsi-target specific TMR reference leak
during session shutdown, that could occur when a TMR was
quiesced before the hand-off back to iscsi-target code
via transport_cmd_check_stop_to_fabric().
The reference leak happens because iscsit_free_cmd() was
incorrectly skipping the final target_put_sess_cmd() for
TMRs when transport_generic_free_cmd() returned zero because
the se_cmd->cmd_kref did not reach zero, due to the missing
se_cmd assignment in original code.
The result was iscsi_cmd and it's associated se_cmd memory
would be freed once se_sess->sess_cmd_map where released,
but the associated se_tmr_req was leaked and remained part
of se_device->dev_tmr_list.
This bug would manfiest itself as kernel paging request
OOPsen in core_tmr_lun_reset(), when a left-over se_tmr_req
attempted to dereference it's se_cmd pointer that had
already been released during normal session shutdown.
To address this bug, go ahead and treat ISCSI_OP_SCSI_CMD
and ISCSI_OP_SCSI_TMFUNC the same when there is an extra
se_cmd->cmd_kref to drop in iscsit_free_cmd(), and use
op_scsi to signal __iscsit_free_cmd() when the former
needs to clear any further iscsi related I/O state.
Reported-by: Rob Millner <rlm@daterainc.com>
Cc: Rob Millner <rlm@daterainc.com>
Reported-by: Chu Yuan Lin <cyl@datera.io>
Cc: Chu Yuan Lin <cyl@datera.io>
Tested-by: Chu Yuan Lin <cyl@datera.io>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_fabric_configfs.c')
0 files changed, 0 insertions, 0 deletions