diff options
| author | Jason Yan <yanaijie@huawei.com> | 2018-09-25 10:56:54 +0800 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2018-09-25 21:20:23 -0400 |
| commit | b90cd6f2b905905fb42671009dc0e27c310a16ae (patch) | |
| tree | 981dfa49113f511ed877ae497b0cba6bf716f89d /drivers | |
| parent | 437207d3697f500f34f126a8ab1c29417ba4a184 (diff) | |
| download | linux-b90cd6f2b905905fb42671009dc0e27c310a16ae.tar.bz2 | |
scsi: libsas: fix a race condition when smp task timeout
When the lldd is processing the complete sas task in interrupt and set the
task stat as SAS_TASK_STATE_DONE, the smp timeout timer is able to be
triggered at the same time. And smp_task_timedout() will complete the task
wheter the SAS_TASK_STATE_DONE is set or not. Then the sas task may freed
before lldd end the interrupt process. Thus a use-after-free will happen.
Fix this by calling the complete() only when SAS_TASK_STATE_DONE is not
set. And remove the check of the return value of the del_timer(). Once the
LLDD sets DONE, it must call task->done(), which will call
smp_task_done()->complete() and the task will be completed and freed
correctly.
Reported-by: chenxiang <chenxiang66@hisilicon.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: Hannes Reinecke <hare@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/libsas/sas_expander.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c index 52222940d398..0d1f72752ca2 100644 --- a/drivers/scsi/libsas/sas_expander.c +++ b/drivers/scsi/libsas/sas_expander.c @@ -48,17 +48,16 @@ static void smp_task_timedout(struct timer_list *t) unsigned long flags; spin_lock_irqsave(&task->task_state_lock, flags); - if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) + if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) { task->task_state_flags |= SAS_TASK_STATE_ABORTED; + complete(&task->slow_task->completion); + } spin_unlock_irqrestore(&task->task_state_lock, flags); - - complete(&task->slow_task->completion); } static void smp_task_done(struct sas_task *task) { - if (!del_timer(&task->slow_task->timer)) - return; + del_timer(&task->slow_task->timer); complete(&task->slow_task->completion); } |