From 0492d857636e1c52cd71594a723c4b26a7b31978 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 16 Mar 2022 11:19:43 +0100 Subject: [PATCH 1/3] netfilter: flowtable: Fix QinQ and pppoe support for inet table nf_flow_offload_inet_hook() does not check for 802.1q and PPPoE. Fetch inner ethertype from these encapsulation protocols. Fixes: 72efd585f714 ("netfilter: flowtable: add pppoe support") Fixes: 4cd91f7c290f ("netfilter: flowtable: add vlan support") Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_flow_table.h | 18 ++++++++++++++++++ net/netfilter/nf_flow_table_inet.c | 17 +++++++++++++++++ net/netfilter/nf_flow_table_ip.c | 18 ------------------ 3 files changed, 35 insertions(+), 18 deletions(-) diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h index bd59e950f4d6..64daafd1fc41 100644 --- a/include/net/netfilter/nf_flow_table.h +++ b/include/net/netfilter/nf_flow_table.h @@ -10,6 +10,8 @@ #include #include #include +#include +#include struct nf_flowtable; struct nf_flow_rule; @@ -317,4 +319,20 @@ int nf_flow_rule_route_ipv6(struct net *net, const struct flow_offload *flow, int nf_flow_table_offload_init(void); void nf_flow_table_offload_exit(void); +static inline __be16 nf_flow_pppoe_proto(const struct sk_buff *skb) +{ + __be16 proto; + + proto = *((__be16 *)(skb_mac_header(skb) + ETH_HLEN + + sizeof(struct pppoe_hdr))); + switch (proto) { + case htons(PPP_IP): + return htons(ETH_P_IP); + case htons(PPP_IPV6): + return htons(ETH_P_IPV6); + } + + return 0; +} + #endif /* _NF_FLOW_TABLE_H */ diff --git a/net/netfilter/nf_flow_table_inet.c b/net/netfilter/nf_flow_table_inet.c index 5c57ade6bd05..0ccabf3fa6aa 100644 --- a/net/netfilter/nf_flow_table_inet.c +++ b/net/netfilter/nf_flow_table_inet.c @@ -6,12 +6,29 @@ #include #include #include +#include static unsigned int nf_flow_offload_inet_hook(void *priv, struct sk_buff *skb, const struct nf_hook_state *state) { + struct vlan_ethhdr *veth; + __be16 proto; + switch (skb->protocol) { + case htons(ETH_P_8021Q): + veth = (struct vlan_ethhdr *)skb_mac_header(skb); + proto = veth->h_vlan_encapsulated_proto; + break; + case htons(ETH_P_PPP_SES): + proto = nf_flow_pppoe_proto(skb); + break; + default: + proto = skb->protocol; + break; + } + + switch (proto) { case htons(ETH_P_IP): return nf_flow_offload_ip_hook(priv, skb, state); case htons(ETH_P_IPV6): diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 889cf88d3dba..6257d87c3a56 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -8,8 +8,6 @@ #include #include #include -#include -#include #include #include #include @@ -239,22 +237,6 @@ static unsigned int nf_flow_xmit_xfrm(struct sk_buff *skb, return NF_STOLEN; } -static inline __be16 nf_flow_pppoe_proto(const struct sk_buff *skb) -{ - __be16 proto; - - proto = *((__be16 *)(skb_mac_header(skb) + ETH_HLEN + - sizeof(struct pppoe_hdr))); - switch (proto) { - case htons(PPP_IP): - return htons(ETH_P_IP); - case htons(PPP_IPV6): - return htons(ETH_P_IPV6); - } - - return 0; -} - static bool nf_flow_skb_encap_protocol(const struct sk_buff *skb, __be16 proto, u32 *offset) { From 6e1acfa387b9ff82cfc7db8cc3b6959221a95851 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 17 Mar 2022 11:59:26 +0100 Subject: [PATCH 2/3] netfilter: nf_tables: validate registers coming from userspace. Bail out in case userspace uses unsupported registers. Fixes: 49499c3e6e18 ("netfilter: nf_tables: switch registers to 32 bit addressing") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index d71a33ae39b3..1f5a0eece0d1 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -9275,17 +9275,23 @@ int nft_parse_u32_check(const struct nlattr *attr, int max, u32 *dest) } EXPORT_SYMBOL_GPL(nft_parse_u32_check); -static unsigned int nft_parse_register(const struct nlattr *attr) +static unsigned int nft_parse_register(const struct nlattr *attr, u32 *preg) { unsigned int reg; reg = ntohl(nla_get_be32(attr)); switch (reg) { case NFT_REG_VERDICT...NFT_REG_4: - return reg * NFT_REG_SIZE / NFT_REG32_SIZE; + *preg = reg * NFT_REG_SIZE / NFT_REG32_SIZE; + break; + case NFT_REG32_00...NFT_REG32_15: + *preg = reg + NFT_REG_SIZE / NFT_REG32_SIZE - NFT_REG32_00; + break; default: - return reg + NFT_REG_SIZE / NFT_REG32_SIZE - NFT_REG32_00; + return -ERANGE; } + + return 0; } /** @@ -9327,7 +9333,10 @@ int nft_parse_register_load(const struct nlattr *attr, u8 *sreg, u32 len) u32 reg; int err; - reg = nft_parse_register(attr); + err = nft_parse_register(attr, ®); + if (err < 0) + return err; + err = nft_validate_register_load(reg, len); if (err < 0) return err; @@ -9382,7 +9391,10 @@ int nft_parse_register_store(const struct nft_ctx *ctx, int err; u32 reg; - reg = nft_parse_register(attr); + err = nft_parse_register(attr, ®); + if (err < 0) + return err; + err = nft_validate_register_store(ctx, reg, data, type, len); if (err < 0) return err; From 4c905f6740a365464e91467aa50916555b28213d Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 17 Mar 2022 12:04:42 +0100 Subject: [PATCH 3/3] netfilter: nf_tables: initialize registers in nft_do_chain() Initialize registers to avoid stack leak into userspace. Fixes: 96518518cc41 ("netfilter: add nftables") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c index 36e73f9828c5..8af98239655d 100644 --- a/net/netfilter/nf_tables_core.c +++ b/net/netfilter/nf_tables_core.c @@ -201,7 +201,7 @@ nft_do_chain(struct nft_pktinfo *pkt, void *priv) const struct nft_rule_dp *rule, *last_rule; const struct net *net = nft_net(pkt); const struct nft_expr *expr, *last; - struct nft_regs regs; + struct nft_regs regs = {}; unsigned int stackptr = 0; struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE]; bool genbit = READ_ONCE(net->nft.gencursor);