diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2024-08-13 12:39:46 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2024-08-22 12:14:18 +0200 |
| commit | 6ea14ccb60c8ab829349979b22b58a941ec4a3ee (patch) | |
| tree | 368e79a57fd09ebf0d94917d038f4b9a861d3fd6 /net | |
| parent | a0b39e2dc7017ac667b70bdeee5293e410fab2fb (diff) | |
netfilter: flowtable: validate vlan header
Ensure there is sufficient room to access the protocol field of the
VLAN header, validate it once before the flowtable lookup.
=====================================================
BUG: KMSAN: uninit-value in nf_flow_offload_inet_hook+0x45a/0x5f0 net/netfilter/nf_flow_table_inet.c:32
nf_flow_offload_inet_hook+0x45a/0x5f0 net/netfilter/nf_flow_table_inet.c:32
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline]
nf_ingress net/core/dev.c:5440 [inline]
Fixes: 4cd91f7c290f ("netfilter: flowtable: add vlan support")
Reported-by: syzbot+8407d9bb88cd4c6bf61a@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_flow_table_inet.c | 3 | ||||
| -rw-r--r-- | net/netfilter/nf_flow_table_ip.c | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/net/netfilter/nf_flow_table_inet.c b/net/netfilter/nf_flow_table_inet.c index 88787b45e30d..8b541a080342 100644 --- a/net/netfilter/nf_flow_table_inet.c +++ b/net/netfilter/nf_flow_table_inet.c @@ -17,6 +17,9 @@ nf_flow_offload_inet_hook(void *priv, struct sk_buff *skb, switch (skb->protocol) { case htons(ETH_P_8021Q): + if (!pskb_may_pull(skb, skb_mac_offset(skb) + sizeof(*veth))) + return NF_ACCEPT; + veth = (struct vlan_ethhdr *)skb_mac_header(skb); proto = veth->h_vlan_encapsulated_proto; break; diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index c2c005234dcd..98edcaa37b38 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -281,6 +281,9 @@ static bool nf_flow_skb_encap_protocol(struct sk_buff *skb, __be16 proto, switch (skb->protocol) { case htons(ETH_P_8021Q): + if (!pskb_may_pull(skb, skb_mac_offset(skb) + sizeof(*veth))) + return false; + veth = (struct vlan_ethhdr *)skb_mac_header(skb); if (veth->h_vlan_encapsulated_proto == proto) { *offset += VLAN_HLEN; |