Re: [PATCH net 1/2] vhost: use mutex_lock_nested() in vhost_dev_lock_vqs()

From: David Miller
Date: Wed Jan 24 2018 - 16:38:39 EST


From: Jason Wang <jasowang@xxxxxxxxxx>
Date: Tue, 23 Jan 2018 17:27:25 +0800

> We used to call mutex_lock() in vhost_dev_lock_vqs() which tries to
> hold mutexes of all virtqueues. This may confuse lockdep to report a
> possible deadlock because of trying to hold locks belong to same
> class. Switch to use mutex_lock_nested() to avoid false positive.
>
> Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API")
> Reported-by: syzbot+dbb7c1161485e61b0241@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>

Michael, I see you ACK'd this, meaning that you're OK with these two
fixes going via my net tree?

Thanks.