diff options
| author | Heng Qi <hengqi@linux.alibaba.com> | 2023-01-31 16:50:04 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-02-01 21:31:56 -0800 |
| commit | 981f14d42a7f1610292a1ef0f7cd00138fff361d (patch) | |
| tree | 43f4d15d7a4353b1ac99de3a16baaaf985dcc1eb /drivers/net/virtio_net.c | |
| parent | 028fb19c6ba743ed308ba99ac325afa968795e0f (diff) | |
virtio-net: fix possible unsigned integer overflow
When the single-buffer xdp is loaded and after xdp_linearize_page()
is called, *num_buf becomes 0 and (*num_buf - 1) may overflow into
a large integer in virtnet_build_xdp_buff_mrg(), resulting in
unexpected packet dropping.
Fixes: ef75cb51f139 ("virtio-net: build xdp_buff with multi buffers")
Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20230131085004.98687-1-hengqi@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/virtio_net.c')
| -rw-r--r-- | drivers/net/virtio_net.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ab5c275965e2..0f0036b1514d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -723,7 +723,7 @@ static unsigned int virtnet_get_headroom(struct virtnet_info *vi) * have enough headroom. */ static struct page *xdp_linearize_page(struct receive_queue *rq, - u16 *num_buf, + int *num_buf, struct page *p, int offset, int page_off, @@ -823,7 +823,7 @@ static struct sk_buff *receive_small(struct net_device *dev, if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) { int offset = buf - page_address(page) + header_offset; unsigned int tlen = len + vi->hdr_len; - u16 num_buf = 1; + int num_buf = 1; xdp_headroom = virtnet_get_headroom(vi); header_offset = VIRTNET_RX_PAD + xdp_headroom; @@ -996,7 +996,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, void *buf, unsigned int len, unsigned int frame_sz, - u16 *num_buf, + int *num_buf, unsigned int *xdp_frags_truesize, struct virtnet_rq_stats *stats) { @@ -1014,6 +1014,9 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, xdp_prepare_buff(xdp, buf - VIRTIO_XDP_HEADROOM, VIRTIO_XDP_HEADROOM + vi->hdr_len, len - vi->hdr_len, true); + if (!*num_buf) + return 0; + if (*num_buf > 1) { /* If we want to build multi-buffer xdp, we need * to specify that the flags of xdp_buff have the @@ -1027,10 +1030,10 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, shinfo->xdp_frags_size = 0; } - if ((*num_buf - 1) > MAX_SKB_FRAGS) + if (*num_buf > MAX_SKB_FRAGS + 1) return -EINVAL; - while ((--*num_buf) >= 1) { + while (--*num_buf > 0) { buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx); if (unlikely(!buf)) { pr_debug("%s: rx error: %d buffers out of %d missing\n", @@ -1083,7 +1086,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, struct virtnet_rq_stats *stats) { struct virtio_net_hdr_mrg_rxbuf *hdr = buf; - u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers); + int num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers); struct page *page = virt_to_head_page(buf); int offset = buf - page_address(page); struct sk_buff *head_skb, *curr_skb; |