From: Prasad J Pandit <p...@fedoraproject.org>
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 <luodalon...@gmail.com>
Signed-off-by: Prasad J Pandit <p...@fedoraproject.org>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
Reviewed-by: Laszlo Ersek <ler...@redhat.com>
---
hw/virtio/virtio.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index fcf3358..bb656b1 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;
--
MST
