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| author | Jason Wang <jasowang@redhat.com> | 2018-05-22 19:58:57 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-06-11 22:49:21 +0200 |
| commit | 6d431f6e6880b7c626650326ba4c72c50b1426f8 (patch) | |
| tree | dac7c07df2ffa226617a500a921766a0f107f341 /drivers/vhost/vhost.c | |
| parent | f2bb94069f3e88ca9d62eec614ace16d03695b4a (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>
Diffstat (limited to 'drivers/vhost/vhost.c')
| -rw-r--r-- | drivers/vhost/vhost.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 8e3ca4400766..50e48afd88ff 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -993,6 +993,7 @@ 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: @@ -1024,6 +1025,8 @@ 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, |