From f2eea93c6b410efccc18f4b47090b4a4e842afbd Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 6 Feb 2024 14:06:08 -0500 Subject: [PATCH] virtio-blk: add vq_rq[] bounds check in virtio_blk_dma_restart_cb() Hanna Czenczek noted that the array index in virtio_blk_dma_restart_cb() is not bounds-checked: g_autofree VirtIOBlockReq **vq_rq = g_new0(VirtIOBlockReq *, num_queues); ... while (rq) { VirtIOBlockReq *next = rq->next; uint16_t idx = virtio_get_queue_index(rq->vq); rq->next = vq_rq[idx]; ^^^^^^^^^^ The code is correct because both rq->vq and vq_rq[] depend on num_queues, but this is indirect and not 100% obvious. Add an assertion. Suggested-by: Hanna Czenczek Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek Signed-off-by: Stefan Hajnoczi Message-ID: <20240206190610.107963-4-stefanha@redhat.com> Reviewed-by: Kevin Wolf Reviewed-by: Michael S. Tsirkin Signed-off-by: Kevin Wolf --- hw/block/virtio-blk.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index e430ba583c..31212506ca 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1209,6 +1209,8 @@ static void virtio_blk_dma_restart_cb(void *opaque, bool running, VirtIOBlockReq *next = rq->next; uint16_t idx = virtio_get_queue_index(rq->vq); + /* Only num_queues vqs were created so vq_rq[idx] is within bounds */ + assert(idx < num_queues); rq->next = vq_rq[idx]; vq_rq[idx] = rq; rq = next;