From: Eric Auger <eric.au...@redhat.com>
In the virtio_iommu_handle_command() when a PROBE request is handled,
output_size takes a value greater than the tail size and on a subsequent
iteration we can get a stack out-of-band access. Initialize the
output_size on each iteration.
The issue was found with ASAN. Credits to:
Yiming Tao(Zhejiang University)
Gaoning Pan(Zhejiang University)
Fixes: 1733eebb9e7 ("virtio-iommu: Implement RESV_MEM probe request")
Signed-off-by: Eric Auger <eric.au...@redhat.com>
Reported-by: Mauro Matteo Cascella <mcasc...@redhat.com>
Cc: qemu-sta...@nongnu.org
Message-Id: <20230717162126.11693-1-eric.au...@redhat.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
(cherry picked from commit cf2f89edf36a59183166ae8721a8d7ab5cd286bd)
Signed-off-by: Michael Tokarev <m...@tls.msk.ru>
diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index 1cd258135d..e84300d50c 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -727,13 +727,15 @@ static void virtio_iommu_handle_command(VirtIODevice
*vdev, VirtQueue *vq)
VirtIOIOMMU *s = VIRTIO_IOMMU(vdev);
struct virtio_iommu_req_head head;
struct virtio_iommu_req_tail tail = {};
- size_t output_size = sizeof(tail), sz;
VirtQueueElement *elem;
unsigned int iov_cnt;
struct iovec *iov;
void *buf = NULL;
+ size_t sz;
for (;;) {
+ size_t output_size = sizeof(tail);
+
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
return;
--
2.39.2
