diff options
| author | Prasad J Pandit <pjp@fedoraproject.org> | 2016-09-19 23:55:45 +0530 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2016-09-23 18:51:40 +0300 |
| commit | 973e7170dddefb491a48df5cba33b2ae151013a0 (patch) | |
| tree | e442e4cf4fb0110660249c5638f9ad960a31787a | |
| parent | 9294d76c15e5d0cabc626bc4d95f95f896abc8d0 (diff) | |
| download | qemu-973e7170dddefb491a48df5cba33b2ae151013a0.zip | |
virtio: add check for descriptor's mapped address
virtio back end uses set of buffers to facilitate I/O operations.
If its size is too large, 'cpu_physical_memory_map' could return
a null address. This would result in a null dereference while
un-mapping descriptors. Add check to avoid it.
Reported-by: Qinghao Tang <luodalongde@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
| -rw-r--r-- | hw/virtio/virtio.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index fcf3358d6c..bb656b1ccf 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -495,6 +495,11 @@ static void virtqueue_map_desc(unsigned int *p_num_sg, hwaddr *addr, struct iove } iov[num_sg].iov_base = cpu_physical_memory_map(pa, &len, is_write); + if (!iov[num_sg].iov_base) { + error_report("virtio: bogus descriptor or out of resources"); + exit(1); + } + iov[num_sg].iov_len = len; addr[num_sg] = pa; |