From ab2d7251d666995740da17b2a51ca545ac5dd037 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 10 Oct 2014 11:25:20 +0200 Subject: netfilter: missing module license in the nf_reject_ipvX modules [ 23.545204] nf_reject_ipv4: module license 'unspecified' taints kernel. Fixes: c8d7b98 ("netfilter: move nf_send_resetX() code to nf_reject_ipvX modules") Reported-by: Dave Young Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/nf_reject_ipv6.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/ipv6/netfilter') diff --git a/net/ipv6/netfilter/nf_reject_ipv6.c b/net/ipv6/netfilter/nf_reject_ipv6.c index 5f5f0438d74d..20d9defc6c59 100644 --- a/net/ipv6/netfilter/nf_reject_ipv6.c +++ b/net/ipv6/netfilter/nf_reject_ipv6.c @@ -5,6 +5,8 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ + +#include #include #include #include @@ -161,3 +163,5 @@ void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook) ip6_local_out(nskb); } EXPORT_SYMBOL_GPL(nf_send_reset6); + +MODULE_LICENSE("GPL"); -- cgit v1.2.3 From 7210e4e38f945dfa173c4a4e59ad827c9ecad541 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 13 Oct 2014 19:50:22 +0200 Subject: netfilter: nf_tables: restrict nat/masq expressions to nat chain type This adds the missing validation code to avoid the use of nat/masq from non-nat chains. The validation assumes two possible configuration scenarios: 1) Use of nat from base chain that is not of nat type. Reject this configuration from the nft_*_init() path of the expression. 2) Use of nat from non-base chain. In this case, we have to wait until the non-base chain is referenced by at least one base chain via jump/goto. This is resolved from the nft_*_validate() path which is called from nf_tables_check_loops(). The user gets an -EOPNOTSUPP in both cases. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 3 +++ include/net/netfilter/nft_masq.h | 3 +++ net/ipv4/netfilter/nft_masq_ipv4.c | 1 + net/ipv6/netfilter/nft_masq_ipv6.c | 1 + net/netfilter/nf_tables_api.c | 14 ++++++++++++++ net/netfilter/nft_masq.c | 12 ++++++++++++ net/netfilter/nft_nat.c | 12 ++++++++++++ 7 files changed, 46 insertions(+) (limited to 'net/ipv6/netfilter') diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 3d7292392fac..845c596bf594 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -530,6 +530,9 @@ enum nft_chain_type { NFT_CHAIN_T_MAX }; +int nft_chain_validate_dependency(const struct nft_chain *chain, + enum nft_chain_type type); + struct nft_stats { u64 bytes; u64 pkts; diff --git a/include/net/netfilter/nft_masq.h b/include/net/netfilter/nft_masq.h index c72729f954f4..e2a518b60e19 100644 --- a/include/net/netfilter/nft_masq.h +++ b/include/net/netfilter/nft_masq.h @@ -13,4 +13,7 @@ int nft_masq_init(const struct nft_ctx *ctx, int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr); +int nft_masq_validate(const struct nft_ctx *ctx, const struct nft_expr *expr, + const struct nft_data **data); + #endif /* _NFT_MASQ_H_ */ diff --git a/net/ipv4/netfilter/nft_masq_ipv4.c b/net/ipv4/netfilter/nft_masq_ipv4.c index 1c636d6b5b50..c1023c445920 100644 --- a/net/ipv4/netfilter/nft_masq_ipv4.c +++ b/net/ipv4/netfilter/nft_masq_ipv4.c @@ -39,6 +39,7 @@ static const struct nft_expr_ops nft_masq_ipv4_ops = { .eval = nft_masq_ipv4_eval, .init = nft_masq_init, .dump = nft_masq_dump, + .validate = nft_masq_validate, }; static struct nft_expr_type nft_masq_ipv4_type __read_mostly = { diff --git a/net/ipv6/netfilter/nft_masq_ipv6.c b/net/ipv6/netfilter/nft_masq_ipv6.c index 556262f40761..8a7ac685076d 100644 --- a/net/ipv6/netfilter/nft_masq_ipv6.c +++ b/net/ipv6/netfilter/nft_masq_ipv6.c @@ -39,6 +39,7 @@ static const struct nft_expr_ops nft_masq_ipv6_ops = { .eval = nft_masq_ipv6_eval, .init = nft_masq_init, .dump = nft_masq_dump, + .validate = nft_masq_validate, }; static struct nft_expr_type nft_masq_ipv6_type __read_mostly = { diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 556a0dfa4abc..65eb2a1160d5 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3744,6 +3744,20 @@ static const struct nfnetlink_subsystem nf_tables_subsys = { .abort = nf_tables_abort, }; +int nft_chain_validate_dependency(const struct nft_chain *chain, + enum nft_chain_type type) +{ + const struct nft_base_chain *basechain; + + if (chain->flags & NFT_BASE_CHAIN) { + basechain = nft_base_chain(chain); + if (basechain->type->type != type) + return -EOPNOTSUPP; + } + return 0; +} +EXPORT_SYMBOL_GPL(nft_chain_validate_dependency); + /* * Loop detection - walk through the ruleset beginning at the destination chain * of a new jump until either the source chain is reached (loop) or all diff --git a/net/netfilter/nft_masq.c b/net/netfilter/nft_masq.c index 6637bab00567..d1ffd5eb3a9b 100644 --- a/net/netfilter/nft_masq.c +++ b/net/netfilter/nft_masq.c @@ -26,6 +26,11 @@ int nft_masq_init(const struct nft_ctx *ctx, const struct nlattr * const tb[]) { struct nft_masq *priv = nft_expr_priv(expr); + int err; + + err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT); + if (err < 0) + return err; if (tb[NFTA_MASQ_FLAGS] == NULL) return 0; @@ -55,5 +60,12 @@ nla_put_failure: } EXPORT_SYMBOL_GPL(nft_masq_dump); +int nft_masq_validate(const struct nft_ctx *ctx, const struct nft_expr *expr, + const struct nft_data **data) +{ + return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT); +} +EXPORT_SYMBOL_GPL(nft_masq_validate); + MODULE_LICENSE("GPL"); MODULE_AUTHOR("Arturo Borrero Gonzalez "); diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c index 799550b476fb..0f0af6e86fb8 100644 --- a/net/netfilter/nft_nat.c +++ b/net/netfilter/nft_nat.c @@ -95,6 +95,10 @@ static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr, u32 family; int err; + err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT); + if (err < 0) + return err; + if (tb[NFTA_NAT_TYPE] == NULL) return -EINVAL; @@ -205,6 +209,13 @@ nla_put_failure: return -1; } +static int nft_nat_validate(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nft_data **data) +{ + return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT); +} + static struct nft_expr_type nft_nat_type; static const struct nft_expr_ops nft_nat_ops = { .type = &nft_nat_type, @@ -212,6 +223,7 @@ static const struct nft_expr_ops nft_nat_ops = { .eval = nft_nat_eval, .init = nft_nat_init, .dump = nft_nat_dump, + .validate = nft_nat_validate, }; static struct nft_expr_type nft_nat_type __read_mostly = { -- cgit v1.2.3 From 8bfcdf6671b1c8006c52c3eaf9fd1b5dfcf41c3d Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 26 Oct 2014 12:35:54 +0100 Subject: netfilter: nf_reject_ipv6: split nf_send_reset6() in smaller functions That can be reused by the reject bridge expression to build the reject packet. The new functions are: * nf_reject_ip6_tcphdr_get(): to sanitize and to obtain the TCP header. * nf_reject_ip6hdr_put(): to build the IPv6 header. * nf_reject_ip6_tcphdr_put(): to build the TCP header. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/ipv6/nf_reject.h | 10 ++ net/ipv6/netfilter/nf_reject_ipv6.c | 175 ++++++++++++++++++++------------- 2 files changed, 119 insertions(+), 66 deletions(-) (limited to 'net/ipv6/netfilter') diff --git a/include/net/netfilter/ipv6/nf_reject.h b/include/net/netfilter/ipv6/nf_reject.h index 48e18810a9be..23216d48abf9 100644 --- a/include/net/netfilter/ipv6/nf_reject.h +++ b/include/net/netfilter/ipv6/nf_reject.h @@ -15,4 +15,14 @@ nf_send_unreach6(struct net *net, struct sk_buff *skb_in, unsigned char code, void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook); +const struct tcphdr *nf_reject_ip6_tcphdr_get(struct sk_buff *oldskb, + struct tcphdr *otcph, + unsigned int *otcplen, int hook); +struct ipv6hdr *nf_reject_ip6hdr_put(struct sk_buff *nskb, + const struct sk_buff *oldskb, + __be16 protocol, int hoplimit); +void nf_reject_ip6_tcphdr_put(struct sk_buff *nskb, + const struct sk_buff *oldskb, + const struct tcphdr *oth, unsigned int otcplen); + #endif /* _IPV6_NF_REJECT_H */ diff --git a/net/ipv6/netfilter/nf_reject_ipv6.c b/net/ipv6/netfilter/nf_reject_ipv6.c index 20d9defc6c59..015eb8a80766 100644 --- a/net/ipv6/netfilter/nf_reject_ipv6.c +++ b/net/ipv6/netfilter/nf_reject_ipv6.c @@ -12,116 +12,102 @@ #include #include #include +#include -void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook) +const struct tcphdr *nf_reject_ip6_tcphdr_get(struct sk_buff *oldskb, + struct tcphdr *otcph, + unsigned int *otcplen, int hook) { - struct sk_buff *nskb; - struct tcphdr otcph, *tcph; - unsigned int otcplen, hh_len; - int tcphoff, needs_ack; const struct ipv6hdr *oip6h = ipv6_hdr(oldskb); - struct ipv6hdr *ip6h; -#define DEFAULT_TOS_VALUE 0x0U - const __u8 tclass = DEFAULT_TOS_VALUE; - struct dst_entry *dst = NULL; u8 proto; __be16 frag_off; - struct flowi6 fl6; - - if ((!(ipv6_addr_type(&oip6h->saddr) & IPV6_ADDR_UNICAST)) || - (!(ipv6_addr_type(&oip6h->daddr) & IPV6_ADDR_UNICAST))) { - pr_debug("addr is not unicast.\n"); - return; - } + int tcphoff; proto = oip6h->nexthdr; - tcphoff = ipv6_skip_exthdr(oldskb, ((u8*)(oip6h+1) - oldskb->data), &proto, &frag_off); + tcphoff = ipv6_skip_exthdr(oldskb, ((u8*)(oip6h+1) - oldskb->data), + &proto, &frag_off); if ((tcphoff < 0) || (tcphoff > oldskb->len)) { pr_debug("Cannot get TCP header.\n"); - return; + return NULL; } - otcplen = oldskb->len - tcphoff; + *otcplen = oldskb->len - tcphoff; /* IP header checks: fragment, too short. */ - if (proto != IPPROTO_TCP || otcplen < sizeof(struct tcphdr)) { - pr_debug("proto(%d) != IPPROTO_TCP, " - "or too short. otcplen = %d\n", - proto, otcplen); - return; + if (proto != IPPROTO_TCP || *otcplen < sizeof(struct tcphdr)) { + pr_debug("proto(%d) != IPPROTO_TCP or too short (len = %d)\n", + proto, *otcplen); + return NULL; } - if (skb_copy_bits(oldskb, tcphoff, &otcph, sizeof(struct tcphdr))) - BUG(); + otcph = skb_header_pointer(oldskb, tcphoff, sizeof(struct tcphdr), + otcph); + if (otcph == NULL) + return NULL; /* No RST for RST. */ - if (otcph.rst) { + if (otcph->rst) { pr_debug("RST is set\n"); - return; + return NULL; } /* Check checksum. */ if (nf_ip6_checksum(oldskb, hook, tcphoff, IPPROTO_TCP)) { pr_debug("TCP checksum is invalid\n"); - return; - } - - memset(&fl6, 0, sizeof(fl6)); - fl6.flowi6_proto = IPPROTO_TCP; - fl6.saddr = oip6h->daddr; - fl6.daddr = oip6h->saddr; - fl6.fl6_sport = otcph.dest; - fl6.fl6_dport = otcph.source; - security_skb_classify_flow(oldskb, flowi6_to_flowi(&fl6)); - dst = ip6_route_output(net, NULL, &fl6); - if (dst == NULL || dst->error) { - dst_release(dst); - return; - } - dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); - if (IS_ERR(dst)) - return; - - hh_len = (dst->dev->hard_header_len + 15)&~15; - nskb = alloc_skb(hh_len + 15 + dst->header_len + sizeof(struct ipv6hdr) - + sizeof(struct tcphdr) + dst->trailer_len, - GFP_ATOMIC); - - if (!nskb) { - net_dbg_ratelimited("cannot alloc skb\n"); - dst_release(dst); - return; + return NULL; } - skb_dst_set(nskb, dst); + return otcph; +} +EXPORT_SYMBOL_GPL(nf_reject_ip6_tcphdr_get); - skb_reserve(nskb, hh_len + dst->header_len); +struct ipv6hdr *nf_reject_ip6hdr_put(struct sk_buff *nskb, + const struct sk_buff *oldskb, + __be16 protocol, int hoplimit) +{ + struct ipv6hdr *ip6h; + const struct ipv6hdr *oip6h = ipv6_hdr(oldskb); +#define DEFAULT_TOS_VALUE 0x0U + const __u8 tclass = DEFAULT_TOS_VALUE; skb_put(nskb, sizeof(struct ipv6hdr)); skb_reset_network_header(nskb); ip6h = ipv6_hdr(nskb); ip6_flow_hdr(ip6h, tclass, 0); - ip6h->hop_limit = ip6_dst_hoplimit(dst); - ip6h->nexthdr = IPPROTO_TCP; + ip6h->hop_limit = hoplimit; + ip6h->nexthdr = protocol; ip6h->saddr = oip6h->daddr; ip6h->daddr = oip6h->saddr; + nskb->protocol = htons(ETH_P_IPV6); + + return ip6h; +} +EXPORT_SYMBOL_GPL(nf_reject_ip6hdr_put); + +void nf_reject_ip6_tcphdr_put(struct sk_buff *nskb, + const struct sk_buff *oldskb, + const struct tcphdr *oth, unsigned int otcplen) +{ + struct tcphdr *tcph; + int needs_ack; + skb_reset_transport_header(nskb); tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr)); /* Truncate to length (no data) */ tcph->doff = sizeof(struct tcphdr)/4; - tcph->source = otcph.dest; - tcph->dest = otcph.source; + tcph->source = oth->dest; + tcph->dest = oth->source; - if (otcph.ack) { + if (oth->ack) { needs_ack = 0; - tcph->seq = otcph.ack_seq; + tcph->seq = oth->ack_seq; tcph->ack_seq = 0; } else { needs_ack = 1; - tcph->ack_seq = htonl(ntohl(otcph.seq) + otcph.syn + otcph.fin - + otcplen - (otcph.doff<<2)); + tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin + + otcplen - (oth->doff<<2)); tcph->seq = 0; } @@ -139,6 +125,63 @@ void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook) sizeof(struct tcphdr), IPPROTO_TCP, csum_partial(tcph, sizeof(struct tcphdr), 0)); +} +EXPORT_SYMBOL_GPL(nf_reject_ip6_tcphdr_put); + +void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook) +{ + struct sk_buff *nskb; + struct tcphdr _otcph; + const struct tcphdr *otcph; + unsigned int otcplen, hh_len; + const struct ipv6hdr *oip6h = ipv6_hdr(oldskb); + struct ipv6hdr *ip6h; + struct dst_entry *dst = NULL; + struct flowi6 fl6; + + if ((!(ipv6_addr_type(&oip6h->saddr) & IPV6_ADDR_UNICAST)) || + (!(ipv6_addr_type(&oip6h->daddr) & IPV6_ADDR_UNICAST))) { + pr_debug("addr is not unicast.\n"); + return; + } + + otcph = nf_reject_ip6_tcphdr_get(oldskb, &_otcph, &otcplen, hook); + if (!otcph) + return; + + memset(&fl6, 0, sizeof(fl6)); + fl6.flowi6_proto = IPPROTO_TCP; + fl6.saddr = oip6h->daddr; + fl6.daddr = oip6h->saddr; + fl6.fl6_sport = otcph->dest; + fl6.fl6_dport = otcph->source; + security_skb_classify_flow(oldskb, flowi6_to_flowi(&fl6)); + dst = ip6_route_output(net, NULL, &fl6); + if (dst == NULL || dst->error) { + dst_release(dst); + return; + } + dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); + if (IS_ERR(dst)) + return; + + hh_len = (dst->dev->hard_header_len + 15)&~15; + nskb = alloc_skb(hh_len + 15 + dst->header_len + sizeof(struct ipv6hdr) + + sizeof(struct tcphdr) + dst->trailer_len, + GFP_ATOMIC); + + if (!nskb) { + net_dbg_ratelimited("cannot alloc skb\n"); + dst_release(dst); + return; + } + + skb_dst_set(nskb, dst); + + skb_reserve(nskb, hh_len + dst->header_len); + ip6h = nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_TCP, + ip6_dst_hoplimit(dst)); + nf_reject_ip6_tcphdr_put(nskb, oldskb, otcph, otcplen); nf_ct_attach(nskb, oldskb); -- cgit v1.2.3 From 6b96686ecffcbea85dcb502e4584e4a20a2bfb29 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 7 Nov 2014 15:34:54 +0100 Subject: netfilter: nft_masq: fix uninitialized range in nft_masq_{ipv4, ipv6}_eval When transferring from the original range in nf_nat_masquerade_{ipv4,ipv6}() we copy over values from stack in from min_proto/max_proto due to uninitialized range variable in both, nft_masq_{ipv4,ipv6}_eval. As we only initialize flags at this time from nft_masq struct, just zero out the rest. Fixes: 9ba1f726bec09 ("netfilter: nf_tables: add new nft_masq expression") Signed-off-by: Daniel Borkmann Acked-by: Arturo Borrero Gonzalez Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/nft_masq_ipv4.c | 1 + net/ipv6/netfilter/nft_masq_ipv6.c | 1 + 2 files changed, 2 insertions(+) (limited to 'net/ipv6/netfilter') diff --git a/net/ipv4/netfilter/nft_masq_ipv4.c b/net/ipv4/netfilter/nft_masq_ipv4.c index c1023c445920..665de06561cd 100644 --- a/net/ipv4/netfilter/nft_masq_ipv4.c +++ b/net/ipv4/netfilter/nft_masq_ipv4.c @@ -24,6 +24,7 @@ static void nft_masq_ipv4_eval(const struct nft_expr *expr, struct nf_nat_range range; unsigned int verdict; + memset(&range, 0, sizeof(range)); range.flags = priv->flags; verdict = nf_nat_masquerade_ipv4(pkt->skb, pkt->ops->hooknum, diff --git a/net/ipv6/netfilter/nft_masq_ipv6.c b/net/ipv6/netfilter/nft_masq_ipv6.c index 8a7ac685076d..529c119cbb14 100644 --- a/net/ipv6/netfilter/nft_masq_ipv6.c +++ b/net/ipv6/netfilter/nft_masq_ipv6.c @@ -25,6 +25,7 @@ static void nft_masq_ipv6_eval(const struct nft_expr *expr, struct nf_nat_range range; unsigned int verdict; + memset(&range, 0, sizeof(range)); range.flags = priv->flags; verdict = nf_nat_masquerade_ipv6(pkt->skb, &range, pkt->out); -- cgit v1.2.3