4.9-stable patches

added patches:
	scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch
	series

diff --git a/queue-4.9/scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch b/queue-4.9/scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch
new file mode 100644 (file)
index 0000000..562a455
--- /dev/null
+++ b/queue-4.9/scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch
@@ -0,0 +1,65 @@
+From b90cd6f2b905905fb42671009dc0e27c310a16ae Mon Sep 17 00:00:00 2001
+From: Jason Yan <yanaijie@huawei.com>
+Date: Tue, 25 Sep 2018 10:56:54 +0800
+Subject: scsi: libsas: fix a race condition when smp task timeout
+
+From: Jason Yan <yanaijie@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 <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>
+Cc: Guenter Roeck <linux@roeck-us.net
+Signed-off-by: Greg Kroah-Hartman <gregkh@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
+@@ -47,17 +47,16 @@ static void smp_task_timedout(unsigned l
+       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);
+ }
+ 

diff --git a/queue-4.9/series b/queue-4.9/series
new file mode 100644 (file)
index 0000000..e1b7355
--- /dev/null
+++ b/queue-4.9/series
@@ -0,0 +1 @@
+scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch