6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
[ 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@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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);
--
2.43.0
