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Patch-mainline: v6.3
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Git-commit: 853618d5886bf94812f31228091cd37d308230f7
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References: git-fixes
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From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
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Juergen Gross |
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Date: Fri, 14 Apr 2023 14:08:35 +0800
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Subject: [PATCH] virtio_net: bugfix overflow inside xdp_linearize_page()
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Juergen Gross |
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Juergen Gross |
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Here we copy the data from the original buf to the new page. But we
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not check that it may be overflow.
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Juergen Gross |
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Juergen Gross |
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As long as the size received(including vnethdr) is greater than 3840
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(PAGE_SIZE -VIRTIO_XDP_HEADROOM). Then the memcpy will overflow.
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Juergen Gross |
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Juergen Gross |
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And this is completely possible, as long as the MTU is large, such
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as 4096. In our test environment, this will cause crash. Since crash is
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caused by the written memory, it is meaningless, so I do not include it.
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Juergen Gross |
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Juergen Gross |
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Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers")
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Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
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Acked-by: Jason Wang <jasowang@redhat.com>
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Acked-by: Michael S. Tsirkin <mst@redhat.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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Juergen Gross |
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Signed-off-by: Juergen Gross <jgross@suse.com>
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---
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drivers/net/virtio_net.c | 8 ++++++--
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1 file changed, 6 insertions(+), 2 deletions(-)
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diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
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index 2396c28c0122..ea1bd4bb326d 100644
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--- a/drivers/net/virtio_net.c
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+++ b/drivers/net/virtio_net.c
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@@ -814,8 +814,13 @@ static struct page *xdp_linearize_page(struct receive_queue *rq,
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int page_off,
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unsigned int *len)
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{
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- struct page *page = alloc_page(GFP_ATOMIC);
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+ int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
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+ struct page *page;
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+
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+ if (page_off + *len + tailroom > PAGE_SIZE)
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+ return NULL;
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+ page = alloc_page(GFP_ATOMIC);
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if (!page)
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return NULL;
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@@ -823,7 +828,6 @@ static struct page *xdp_linearize_page(struct receive_queue *rq,
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page_off += *len;
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while (--*num_buf) {
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- int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
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unsigned int buflen;
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void *buf;
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int off;
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--
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2.35.3
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