UPSTREAM: vhost: synchronize IOTLB message with dev cleanup
[ Upstream commit
1b15ad683ab42a203f98b67045b40720e99d0e9a ]
DaeRyong Jeong reports a race between vhost_dev_cleanup() and
vhost_process_iotlb_msg():
Thread interleaving:
CPU0 (vhost_process_iotlb_msg) CPU1 (vhost_dev_cleanup)
(In the case of both VHOST_IOTLB_UPDATE and
VHOST_IOTLB_INVALIDATE)
===== =====
vhost_umem_clean(dev->iotlb);
if (!dev->iotlb) {
ret = -EFAULT;
break;
}
dev->iotlb = NULL;
The reason is we don't synchronize between them, fixing by protecting
vhost_process_iotlb_msg() with dev mutex.
Reported-by: DaeRyong Jeong <threeearcat@gmail.com>
Fixes:
6b1e6cc7855b0 ("vhost: new device IOTLB API")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit
f833209e15bd6cf066e731463308f0058736a74b)
Bug:
121166534
Test: Ran cuttlefish with android-4.4 + VSOCKETS, VMWARE_VMCI_VSOCKETS
Signed-off-by: Alistair Strachan <astrachan@google.com>
Change-Id: I5f372cf9e2d0cf0002ebe01d692e33c3ff52f5d2