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| author | Florian Westphal <fw@strlen.de> | 2022-01-29 17:13:23 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-12 16:34:56 +0200 |
| commit | aa1f19606558a26086d2dd71a8ffc1327ccd451e (patch) | |
| tree | d52b99420a45c79255f0b28b15205dab0850429e /net | |
| parent | 5445819e76a6fbcb9a848efd5569ea27e547f6ab (diff) | |
| download | linux-aa1f19606558a26086d2dd71a8ffc1327ccd451e.tar.gz linux-aa1f19606558a26086d2dd71a8ffc1327ccd451e.tar.bz2 linux-aa1f19606558a26086d2dd71a8ffc1327ccd451e.zip | |
netfilter: nft_payload: don't allow th access for fragments
[ Upstream commit a9e8503def0fd4ed89ade1f61c315f904581d439 ]
Loads relative to ->thoff naturally expect that this points to the
transport header, but this is only true if pkt->fragoff == 0.
This has little effect for rulesets with connection tracking/nat because
these enable ip defra. For other rulesets this prevents false matches.
Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nft_exthdr.c | 2 | ||||
| -rw-r--r-- | net/netfilter/nft_payload.c | 9 |
2 files changed, 6 insertions, 5 deletions
diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index dbe1f2e7dd9e..9e927ab4df15 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -167,7 +167,7 @@ nft_tcp_header_pointer(const struct nft_pktinfo *pkt, { struct tcphdr *tcph; - if (pkt->tprot != IPPROTO_TCP) + if (pkt->tprot != IPPROTO_TCP || pkt->fragoff) return NULL; tcph = skb_header_pointer(pkt->skb, nft_thoff(pkt), sizeof(*tcph), buffer); diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index ee359a4a60f5..b46e01365bd9 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -84,7 +84,7 @@ static int __nft_payload_inner_offset(struct nft_pktinfo *pkt) { unsigned int thoff = nft_thoff(pkt); - if (!(pkt->flags & NFT_PKTINFO_L4PROTO)) + if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) return -1; switch (pkt->tprot) { @@ -148,7 +148,7 @@ void nft_payload_eval(const struct nft_expr *expr, offset = skb_network_offset(skb); break; case NFT_PAYLOAD_TRANSPORT_HEADER: - if (!(pkt->flags & NFT_PKTINFO_L4PROTO)) + if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) goto err; offset = nft_thoff(pkt); break; @@ -658,7 +658,7 @@ static void nft_payload_set_eval(const struct nft_expr *expr, offset = skb_network_offset(skb); break; case NFT_PAYLOAD_TRANSPORT_HEADER: - if (!(pkt->flags & NFT_PKTINFO_L4PROTO)) + if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) goto err; offset = nft_thoff(pkt); break; @@ -697,7 +697,8 @@ static void nft_payload_set_eval(const struct nft_expr *expr, if (priv->csum_type == NFT_PAYLOAD_CSUM_SCTP && pkt->tprot == IPPROTO_SCTP && skb->ip_summed != CHECKSUM_PARTIAL) { - if (nft_payload_csum_sctp(skb, nft_thoff(pkt))) + if (pkt->fragoff == 0 && + nft_payload_csum_sctp(skb, nft_thoff(pkt))) goto err; } |