| Message ID | 20241031100117.152995-5-pablo@netfilter.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d5953d680f7e96208c29ce4139a0e38de87a57fe |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Netfilter fixes for net | expand |
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 330609a76fb2..7dfc5343dae4 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -904,6 +904,9 @@ static void nft_payload_set_eval(const struct nft_expr *expr, ((priv->base != NFT_PAYLOAD_TRANSPORT_HEADER && priv->base != NFT_PAYLOAD_INNER_HEADER) || skb->ip_summed != CHECKSUM_PARTIAL)) { + if (offset + priv->len > skb->len) + goto err; + fsum = skb_checksum(skb, offset, priv->len, 0); tsum = csum_partial(src, priv->len, 0);
If access to offset + length is larger than the skbuff length, then skb_checksum() triggers BUG_ON(). skb_checksum() internally subtracts the length parameter while iterating over skbuff, BUG_ON(len) at the end of it checks that the expected length to be included in the checksum calculation is fully consumed. Fixes: 7ec3f7b47b8d ("netfilter: nft_payload: add packet mangling support") Reported-by: Slavin Liu <slavin-ayu@qq.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/netfilter/nft_payload.c | 3 +++ 1 file changed, 3 insertions(+)