From 7b7eba0f3515fca3296b8881d583f7c1042f5226 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 1 Jun 2016 02:04:44 +0200 Subject: netfilter: x_tables: don't reject valid target size on some architectures Quoting John Stultz: In updating a 32bit arm device from 4.6 to Linus' current HEAD, I noticed I was having some trouble with networking, and realized that /proc/net/ip_tables_names was suddenly empty. Digging through the registration process, it seems we're catching on the: if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 && target_offset + sizeof(struct xt_standard_target) != next_offset) return -EINVAL; Where next_offset seems to be 4 bytes larger then the offset + standard_target struct size. next_offset needs to be aligned via XT_ALIGN (so we can access all members of ip(6)t_entry struct). This problem didn't show up on i686 as it only needs 4-byte alignment for u64, but iptables userspace on other 32bit arches does insert extra padding. Reported-by: John Stultz Tested-by: John Stultz Fixes: 7ed2abddd20cf ("netfilter: x_tables: check standard target size too") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/x_tables.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index c69c892..2675d58 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -612,7 +612,7 @@ int xt_compat_check_entry_offsets(const void *base, const char *elems, return -EINVAL; if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 && - target_offset + sizeof(struct compat_xt_standard_target) != next_offset) + COMPAT_XT_ALIGN(target_offset + sizeof(struct compat_xt_standard_target)) != next_offset) return -EINVAL; /* compat_xt_entry match has less strict aligment requirements, @@ -694,7 +694,7 @@ int xt_check_entry_offsets(const void *base, return -EINVAL; if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 && - target_offset + sizeof(struct xt_standard_target) != next_offset) + XT_ALIGN(target_offset + sizeof(struct xt_standard_target)) != next_offset) return -EINVAL; return xt_check_entry_match(elems, base + target_offset, -- cgit v1.1 From 3ec10d3a2ba591c87da94219c1e46b02ae97757a Mon Sep 17 00:00:00 2001 From: Marco Angaroni Date: Mon, 16 May 2016 19:18:09 +0200 Subject: ipvs: update real-server binding of outgoing connections in SIP-pe Previous patch that introduced handling of outgoing packets in SIP persistent-engine did not call ip_vs_check_template() in case packet was matching a connection template. Assumption was that real-server was healthy, since it was sending a packet just in that moment. There are however real-server fault conditions requiring that association between call-id and real-server (represented by connection template) gets updated. Here is an example of the sequence of events: 1) RS1 is a back2back user agent that handled call-id1 and call-id2 2) RS1 is down and was marked as unavailable 3) new message from outside comes to IPVS with call-id1 4) IPVS reschedules the message to RS2, which becomes new call handler 5) RS2 forwards the message outside, translating call-id1 to call-id2 6) inside pe->conn_out() IPVS matches call-id2 with existing template 7) IPVS does not change association call-id2 <-> RS1 8) new message comes from client with call-id2 9) IPVS reschedules the message to a real-server potentially different from RS2, which is now the correct destination This patch introduces ip_vs_check_template() call in the handling of outgoing packets for SIP-pe. And also introduces a second optional argument for ip_vs_check_template() that allows to check if dest associated to a connection template is the same dest that was identified as the source of the packet. This is to change the real-server bound to a particular call-id independently from its availability status: the idea is that it's more reliable, for in->out direction (where internal network can be considered trusted), to always associate a call-id with the last real-server that used it in one of its messages. Think about above sequence of events where, just after step 5, RS1 returns instead to be available. Comparison of dests is done by simply comparing pointers to struct ip_vs_dest; there should be no cases where struct ip_vs_dest keeps its memory address, but represent a different real-server in terms of ip-address / port. Fixes: 39b972231536 ("ipvs: handle connections started by real-servers") Signed-off-by: Marco Angaroni Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_conn.c | 5 +++-- net/netfilter/ipvs/ip_vs_core.c | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c index 2cb3c62..096a451 100644 --- a/net/netfilter/ipvs/ip_vs_conn.c +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -762,7 +762,7 @@ static int expire_quiescent_template(struct netns_ipvs *ipvs, * If available, return 1, otherwise invalidate this connection * template and return 0. */ -int ip_vs_check_template(struct ip_vs_conn *ct) +int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest) { struct ip_vs_dest *dest = ct->dest; struct netns_ipvs *ipvs = ct->ipvs; @@ -772,7 +772,8 @@ int ip_vs_check_template(struct ip_vs_conn *ct) */ if ((dest == NULL) || !(dest->flags & IP_VS_DEST_F_AVAILABLE) || - expire_quiescent_template(ipvs, dest)) { + expire_quiescent_template(ipvs, dest) || + (cdest && (dest != cdest))) { IP_VS_DBG_BUF(9, "check_template: dest not available for " "protocol %s s:%s:%d v:%s:%d " "-> d:%s:%d\n", diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 1207f20..2c1b498 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -321,7 +321,7 @@ ip_vs_sched_persist(struct ip_vs_service *svc, /* Check if a template already exists */ ct = ip_vs_ct_in_get(¶m); - if (!ct || !ip_vs_check_template(ct)) { + if (!ct || !ip_vs_check_template(ct, NULL)) { struct ip_vs_scheduler *sched; /* @@ -1154,7 +1154,8 @@ struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc, vport, ¶m) < 0) return NULL; ct = ip_vs_ct_in_get(¶m); - if (!ct) { + /* check if template exists and points to the same dest */ + if (!ct || !ip_vs_check_template(ct, dest)) { ct = ip_vs_conn_new(¶m, dest->af, daddr, dport, IP_VS_CONN_F_TEMPLATE, dest, 0); if (!ct) { -- cgit v1.1