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| author |   Pablo Neira Ayuso <pablo@netfilter.org> | 2022-07-05 10:26:15 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2022-07-09 09:55:43 +0200 |
| commit | 7a847c00eeba9744353ecdfad253143b9115678a (patch) | |
| tree | 334ddb11e408b95bc8f44e8daac2284abce96aa3 /net | |
| parent | netfilter: conntrack: fix crash due to confirmed bit load reordering (diff) | |
| download | linux-dev-7a847c00eeba9744353ecdfad253143b9115678a.tar.xz linux-dev-7a847c00eeba9744353ecdfad253143b9115678a.zip | |
netfilter: nf_log: incorrect offset to network header
NFPROTO_ARP is expecting to find the ARP header at the network offset.
In the particular case of ARP, HTYPE= field shows the initial bytes of
the ethernet header destination MAC address.
netdev out: IN= OUT=bridge0 MACSRC=c2:76:e5:71:e1:de MACDST=36:b0:4a:e2:72:ea MACPROTO=0806 ARP HTYPE=14000 PTYPE=0x4ae2 OPCODE=49782
NFPROTO_NETDEV egress hook is also expecting to find the IP headers at
the network offset.
Fixes: 35b9395104d5 ("netfilter: add generic ARP packet logger")
Reported-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_log_syslog.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/net/netfilter/nf_log_syslog.c b/net/netfilter/nf_log_syslog.c index 77bcb10fc586..cb894f0d63e9 100644 --- a/net/netfilter/nf_log_syslog.c +++ b/net/netfilter/nf_log_syslog.c @@ -67,7 +67,7 @@ dump_arp_packet(struct nf_log_buf *m, unsigned int logflags; struct arphdr _arph; - ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); + ah = skb_header_pointer(skb, nhoff, sizeof(_arph), &_arph); if (!ah) { nf_log_buf_add(m, "TRUNCATED"); return; @@ -96,7 +96,7 @@ dump_arp_packet(struct nf_log_buf *m, ah->ar_pln != sizeof(__be32)) return; - ap = skb_header_pointer(skb, sizeof(_arph), sizeof(_arpp), &_arpp); + ap = skb_header_pointer(skb, nhoff + sizeof(_arph), sizeof(_arpp), &_arpp); if (!ap) { nf_log_buf_add(m, " INCOMPLETE [%zu bytes]", skb->len - sizeof(_arph)); @@ -149,7 +149,7 @@ static void nf_log_arp_packet(struct net *net, u_int8_t pf, nf_log_dump_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix); - dump_arp_packet(m, loginfo, skb, 0); + dump_arp_packet(m, loginfo, skb, skb_network_offset(skb)); nf_log_buf_close(m); } @@ -850,7 +850,7 @@ static void nf_log_ip_packet(struct net *net, u_int8_t pf, if (in) dump_mac_header(m, loginfo, skb); - dump_ipv4_packet(net, m, loginfo, skb, 0); + dump_ipv4_packet(net, m, loginfo, skb, skb_network_offset(skb)); nf_log_buf_close(m); } |