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| author | Eugenio Pérez <eperezma@redhat.com> | 2021-01-29 10:07:28 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2021-02-05 08:52:59 -0500 |
| commit | 4d1ccc17f40f73313e13c84914f70ec3d40ac738 (patch) | |
| tree | 2c125e203e85eb7b850ee18f8a79c42003b61b45 | |
| parent | d8be0c6b68c6dac3e2ded573292b52542a1dc814 (diff) | |
| download | qemu-4d1ccc17f40f73313e13c84914f70ec3d40ac738.zip qemu-4d1ccc17f40f73313e13c84914f70ec3d40ac738.tar.gz qemu-4d1ccc17f40f73313e13c84914f70ec3d40ac738.tar.bz2 | |
vhost: Check for valid vdev in vhost_backend_handle_iotlb_msg
Not checking this can lead to invalid dev->vdev member access in
vhost_device_iotlb_miss if backend issue an iotlb message in a bad
timing, either maliciously or by a bug.
Reproduced rebooting a guest with testpmd in txonly forward mode.
#0 0x0000559ffff94394 in vhost_device_iotlb_miss (
dev=dev@entry=0x55a0012f6680, iova=10245279744, write=1)
at ../hw/virtio/vhost.c:1013
#1 0x0000559ffff9ac31 in vhost_backend_handle_iotlb_msg (
imsg=0x7ffddcfd32c0, dev=0x55a0012f6680)
at ../hw/virtio/vhost-backend.c:411
#2 vhost_backend_handle_iotlb_msg (dev=dev@entry=0x55a0012f6680,
imsg=imsg@entry=0x7ffddcfd32c0)
at ../hw/virtio/vhost-backend.c:404
#3 0x0000559fffeded7b in slave_read (opaque=0x55a0012f6680)
at ../hw/virtio/vhost-user.c:1464
#4 0x000055a0000c541b in aio_dispatch_handler (
ctx=ctx@entry=0x55a0010a2120, node=0x55a0012d9e00)
at ../util/aio-posix.c:329
Fixes: 020e571b8b ("vhost: rework IOTLB messaging")
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20210129090728.831208-1-eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | hw/virtio/vhost-backend.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c index 222bbcc..31b33bd 100644 --- a/hw/virtio/vhost-backend.c +++ b/hw/virtio/vhost-backend.c @@ -406,6 +406,11 @@ int vhost_backend_handle_iotlb_msg(struct vhost_dev *dev, { int ret = 0; + if (unlikely(!dev->vdev)) { + error_report("Unexpected IOTLB message when virtio device is stopped"); + return -EINVAL; + } + switch (imsg->type) { case VHOST_IOTLB_MISS: ret = vhost_device_iotlb_miss(dev, imsg->iova, |