diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2017-02-06 14:28:09 -0800 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2017-03-06 17:31:13 -0500 |
| commit | 3d3dc3aa7be4b05a980a55a4e3fc969df7c6250d (patch) | |
| tree | a35ae8dd0629a1d106915180d526e3ba1c4cdd7f | |
| parent | 7722fbf8d70329f729339b3631abe06c0a613c91 (diff) | |
target: Fix COMPARE_AND_WRITE ref leak for non GOOD status
[ Upstream commit 9b2792c3da1e80f2d460167d319302a24c9ca2b7 ]
This patch addresses a long standing bug where the commit phase
of COMPARE_AND_WRITE would result in a se_cmd->cmd_kref reference
leak if se_cmd->scsi_status returned non SAM_STAT_GOOD.
This would manifest first as a lost SCSI response, and eventual
hung task during fabric driver logout or re-login, as existing
shutdown logic waited for the COMPARE_AND_WRITE se_cmd->cmd_kref
to reach zero.
To address this bug, compare_and_write_post() has been changed
to drop the incorrect !cmd->scsi_status conditional that was
preventing *post_ret = 1 for being set during non SAM_STAT_GOOD
status.
This patch has been tested with SAM_STAT_CHECK_CONDITION status
from normal target_complete_cmd() callback path, as well as the
incoming __target_execute_cmd() submission failure path when
se_cmd->execute_cmd() returns non zero status.
Reported-by: Donald White <dew@datera.io>
Cc: Donald White <dew@datera.io>
Tested-by: Gary Guo <ghg@datera.io>
Cc: Gary Guo <ghg@datera.io>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
| -rw-r--r-- | drivers/target/target_core_sbc.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 46b966d09af2..35180fbaa460 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -390,6 +390,7 @@ static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success, int *post_ret) { struct se_device *dev = cmd->se_dev; + sense_reason_t ret = TCM_NO_SENSE; /* * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through @@ -397,9 +398,12 @@ static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success, * sent to the backend driver. */ spin_lock_irq(&cmd->t_state_lock); - if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status) { + if (cmd->transport_state & CMD_T_SENT) { cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST; *post_ret = 1; + + if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION) + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } spin_unlock_irq(&cmd->t_state_lock); @@ -409,7 +413,7 @@ static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success, */ up(&dev->caw_sem); - return TCM_NO_SENSE; + return ret; } static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success, |