summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJason Wang <jasowang@redhat.com>2018-05-22 19:58:57 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-06-13 16:16:43 +0200
commitf833209e15bd6cf066e731463308f0058736a74b (patch)
treee81d5edf654134fd5096db1d5fd7c1e025b6f5fb
parent3ff7364bb06ea807d8ea73206b1b5ec3b0e8a4a9 (diff)
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>
-rw-r--r--drivers/vhost/vhost.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index fce49ebc575d..c81bc4efe1a6 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -938,6 +938,7 @@ int vhost_process_iotlb_msg(struct vhost_dev *dev,
{
int ret = 0;
+ mutex_lock(&dev->mutex);
vhost_dev_lock_vqs(dev);
switch (msg->type) {
case VHOST_IOTLB_UPDATE:
@@ -967,6 +968,8 @@ int vhost_process_iotlb_msg(struct vhost_dev *dev,
}
vhost_dev_unlock_vqs(dev);
+ mutex_unlock(&dev->mutex);
+
return ret;
}
ssize_t vhost_chr_write_iter(struct vhost_dev *dev,