6.1-stable review patch. If anyone has any objections, please let me know.
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From: Pablo Neira Ayuso pablo@netfilter.org
[ Upstream commit 70c261d500951cf3ea0fcf32651aab9a65a91471 ]
From netdev/egress, skb->len can include the ethernet header, therefore,
subtract network offset from skb->len when validating IPv6 packet length.
Fixes: 42df6e1d221d ("netfilter: Introduce egress hook") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/netfilter/nf_tables_ipv6.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/net/netfilter/nf_tables_ipv6.h b/include/net/netfilter/nf_tables_ipv6.h index ec7eaeaf4f04c..f1d6a65280475 100644 --- a/include/net/netfilter/nf_tables_ipv6.h +++ b/include/net/netfilter/nf_tables_ipv6.h @@ -31,8 +31,8 @@ static inline int __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt) struct ipv6hdr *ip6h, _ip6h; unsigned int thoff = 0; unsigned short frag_off; + u32 pkt_len, skb_len; int protohdr; - u32 pkt_len;
ip6h = skb_header_pointer(pkt->skb, skb_network_offset(pkt->skb), sizeof(*ip6h), &_ip6h); @@ -43,7 +43,8 @@ static inline int __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt) return -1;
pkt_len = ntohs(ip6h->payload_len); - if (pkt_len + sizeof(*ip6h) > pkt->skb->len) + skb_len = pkt->skb->len - skb_network_offset(pkt->skb); + if (pkt_len + sizeof(*ip6h) > skb_len) return -1;
protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, &flags);