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authorJason Wang <jasowang@redhat.com>2018-05-22 19:58:57 +0800
committerDavid S. Miller <davem@davemloft.net>2018-05-24 22:09:51 -0400
commit1b15ad683ab42a203f98b67045b40720e99d0e9a (patch)
tree5f9f1adbe56a008b152ffcf9fa86aa3041986b0b /drivers/vhost/vhost.c
parentd681bc027a133f5c19e037f1bd3a142cffc566b4 (diff)
downloadlinux-stericsson-1b15ad683ab42a203f98b67045b40720e99d0e9a.tar.gz
vhost: synchronize IOTLB message with dev cleanup
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>
Diffstat (limited to 'drivers/vhost/vhost.c')
-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 f3bd8e941224..f0be5f35ab28 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -981,6 +981,7 @@ static 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:
@@ -1016,6 +1017,8 @@ static 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,