From b425df4cdd953a400d814b4474c9d3ec04481858 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 25 Jan 2013 18:44:57 +0300 Subject: [PATCH 1/5] ipvs: freeing uninitialized pointer on error If state != IP_VS_STATE_BACKUP then tinfo->buf is uninitialized. If kthread_run() fails then it means we free random memory resulting in an oops. Signed-off-by: Dan Carpenter Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_sync.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c index effa10c9e4e..44fd10c539a 100644 --- a/net/netfilter/ipvs/ip_vs_sync.c +++ b/net/netfilter/ipvs/ip_vs_sync.c @@ -1795,6 +1795,8 @@ int start_sync_thread(struct net *net, int state, char *mcast_ifn, __u8 syncid) GFP_KERNEL); if (!tinfo->buf) goto outtinfo; + } else { + tinfo->buf = NULL; } tinfo->id = id; From 4b47bc9a9e69141ed3a854c57601f548e82c78ba Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Tue, 5 Feb 2013 17:21:31 +0100 Subject: [PATCH 2/5] ipvs: sctp: fix checksumming on snat and dnat handlers In our test lab, we have a simple SCTP client connecting to a SCTP server via an IPVS load balancer. On some machines, load balancing works, but on others the initial handshake just fails, thus no SCTP connection whatsoever can be established! We observed that the SCTP INIT-ACK handshake reply from the IPVS machine to the client had a correct IP checksum, but corrupt SCTP checksum when forwarded, thus on the client-side the packet was dropped and an intial handshake retriggered until all attempts run into the void. To fix this issue, this patch i) adds a missing CHECKSUM_UNNECESSARY after the full checksum (re-)calculation (as done in IPVS TCP and UDP code as well), ii) calculates the checksum in little-endian format (as fixed with the SCTP code in commit 4458f04c: sctp: Clean up sctp checksumming code) and iii) refactors duplicate checksum code into a common function. Tested by myself. Signed-off-by: Daniel Borkmann Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_proto_sctp.c | 35 +++++++++++++-------------- 1 file changed, 17 insertions(+), 18 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c index 746048b13ef..ae8ec6f2768 100644 --- a/net/netfilter/ipvs/ip_vs_proto_sctp.c +++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c @@ -61,14 +61,27 @@ sctp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd, return 1; } +static void sctp_nat_csum(struct sk_buff *skb, sctp_sctphdr_t *sctph, + unsigned int sctphoff) +{ + __u32 crc32; + struct sk_buff *iter; + + crc32 = sctp_start_cksum((__u8 *)sctph, skb_headlen(skb) - sctphoff); + skb_walk_frags(skb, iter) + crc32 = sctp_update_cksum((u8 *) iter->data, + skb_headlen(iter), crc32); + sctph->checksum = sctp_end_cksum(crc32); + + skb->ip_summed = CHECKSUM_UNNECESSARY; +} + static int sctp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) { sctp_sctphdr_t *sctph; unsigned int sctphoff = iph->len; - struct sk_buff *iter; - __be32 crc32; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6 && iph->fragoffs) @@ -92,13 +105,7 @@ sctp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, sctph = (void *) skb_network_header(skb) + sctphoff; sctph->source = cp->vport; - /* Calculate the checksum */ - crc32 = sctp_start_cksum((u8 *) sctph, skb_headlen(skb) - sctphoff); - skb_walk_frags(skb, iter) - crc32 = sctp_update_cksum((u8 *) iter->data, skb_headlen(iter), - crc32); - crc32 = sctp_end_cksum(crc32); - sctph->checksum = crc32; + sctp_nat_csum(skb, sctph, sctphoff); return 1; } @@ -109,8 +116,6 @@ sctp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, { sctp_sctphdr_t *sctph; unsigned int sctphoff = iph->len; - struct sk_buff *iter; - __be32 crc32; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6 && iph->fragoffs) @@ -134,13 +139,7 @@ sctp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, sctph = (void *) skb_network_header(skb) + sctphoff; sctph->dest = cp->dport; - /* Calculate the checksum */ - crc32 = sctp_start_cksum((u8 *) sctph, skb_headlen(skb) - sctphoff); - skb_walk_frags(skb, iter) - crc32 = sctp_update_cksum((u8 *) iter->data, skb_headlen(iter), - crc32); - crc32 = sctp_end_cksum(crc32); - sctph->checksum = crc32; + sctp_nat_csum(skb, sctph, sctphoff); return 1; } From f5271fff56c76e92fde122bcc02f102e99da5c8a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?YOSHIFUJI=20Hideaki=20/=20=E5=90=89=E8=97=A4=E8=8B=B1?= =?UTF-8?q?=E6=98=8E?= Date: Sat, 26 Jan 2013 08:37:48 +0000 Subject: [PATCH 3/5] netfilter: ip6t_NPT: Fix adjustment calculation Cast __wsum from/to __sum16 is wrong. Instead, apply appropriate conversion function: csum_unfold() or csum_fold(). [ The original patch has been modified to undo the final ~ that csum_fold returns. We only need to fold the 32-bit word that results from the checksum calculation into a 16-bit to ensure that the original subnet is restored appropriately. Spotted by Ulrich Weber. ] Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6t_NPT.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c index 7302b0b7b64..68788c84aee 100644 --- a/net/ipv6/netfilter/ip6t_NPT.c +++ b/net/ipv6/netfilter/ip6t_NPT.c @@ -30,7 +30,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par) (__force __wsum)npt->dst_pfx.in6.s6_addr16[i]); } - npt->adjustment = (__force __sum16) csum_sub(src_sum, dst_sum); + npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum)); return 0; } @@ -66,8 +66,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt, return false; } - sum = (__force __sum16) csum_add((__force __wsum)addr->s6_addr16[idx], - npt->adjustment); + sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]), + csum_unfold(npt->adjustment))); if (sum == CSUM_MANGLED_0) sum = 0; *(__force __sum16 *)&addr->s6_addr16[idx] = sum; From d4c38fa87d2b05be5daafb6a92b6ad15b66da8cb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?YOSHIFUJI=20Hideaki=20/=20=E5=90=89=E8=97=A4=E8=8B=B1?= =?UTF-8?q?=E6=98=8E?= Date: Sat, 26 Jan 2013 08:38:44 +0000 Subject: [PATCH 4/5] netfilter: ip6t_NPT: Fix prefix mangling Make sure only the bits that are part of the prefix are mangled. Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6t_NPT.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c index 68788c84aee..87b759c11da 100644 --- a/net/ipv6/netfilter/ip6t_NPT.c +++ b/net/ipv6/netfilter/ip6t_NPT.c @@ -51,7 +51,7 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt, idx = i / 32; addr->s6_addr32[idx] &= mask; - addr->s6_addr32[idx] |= npt->dst_pfx.in6.s6_addr32[idx]; + addr->s6_addr32[idx] |= ~mask & npt->dst_pfx.in6.s6_addr32[idx]; } if (pfx_len <= 48) From edb27228db22654a59711135a5f7a20fb49a1016 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?YOSHIFUJI=20Hideaki=20/=20=E5=90=89=E8=97=A4=E8=8B=B1?= =?UTF-8?q?=E6=98=8E?= Date: Thu, 7 Feb 2013 11:18:22 +0100 Subject: [PATCH 5/5] netfilter: ip6t_NPT: Ensure to check lower part of prefixes are zero RFC 6296 points that address bits that are not part of the prefix has to be zeroed. Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6t_NPT.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c index 87b759c11da..83acc1405a1 100644 --- a/net/ipv6/netfilter/ip6t_NPT.c +++ b/net/ipv6/netfilter/ip6t_NPT.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -18,11 +19,20 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par) { struct ip6t_npt_tginfo *npt = par->targinfo; __wsum src_sum = 0, dst_sum = 0; + struct in6_addr pfx; unsigned int i; if (npt->src_pfx_len > 64 || npt->dst_pfx_len > 64) return -EINVAL; + /* Ensure that LSB of prefix is zero */ + ipv6_addr_prefix(&pfx, &npt->src_pfx.in6, npt->src_pfx_len); + if (!ipv6_addr_equal(&pfx, &npt->src_pfx.in6)) + return -EINVAL; + ipv6_addr_prefix(&pfx, &npt->dst_pfx.in6, npt->dst_pfx_len); + if (!ipv6_addr_equal(&pfx, &npt->dst_pfx.in6)) + return -EINVAL; + for (i = 0; i < ARRAY_SIZE(npt->src_pfx.in6.s6_addr16); i++) { src_sum = csum_add(src_sum, (__force __wsum)npt->src_pfx.in6.s6_addr16[i]);