From: Jason Yan <yanai...@huawei.com>
commit b90cd6f2b905905fb42671009dc0e27c310a16ae upstream.
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 <chenxian...@hisilicon.com>
Signed-off-by: Jason Yan <yanai...@huawei.com>
CC: John Garry <john.ga...@huawei.com>
CC: Johannes Thumshirn <jthumsh...@suse.de>
CC: Ewan Milne <emi...@redhat.com>
CC: Christoph Hellwig <h...@lst.de>
CC: Tomas Henzl <the...@redhat.com>
CC: Dan Williams <dan.j.willi...@intel.com>
CC: Hannes Reinecke <h...@suse.com>
Reviewed-by: Hannes Reinecke <h...@suse.com>
Reviewed-by: John Garry <john.ga...@huawei.com>
Reviewed-by: Johannes Thumshirn <jthumsh...@suse.de>
Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
Cc: Guenter Roeck <li...@roeck-us.net
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/scsi/libsas/sas_expander.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -48,17 +48,16 @@ static void smp_task_timedout(struct tim
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);
}
