From fe8c4bd76af855702ded3a33fae1020f0bc8a533 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 6 Apr 2009 17:31:29 +0200 Subject: [PATCH] netfilter: {ip, ip6, arp}_tables: fix incorrect loop detection upstream commit: 1f9352ae2253a97b07b34dcf16ffa3b4ca12c558 Commit e1b4b9f ([NETFILTER]: {ip,ip6,arp}_tables: fix exponential worst-case search for loops) introduced a regression in the loop detection algorithm, causing sporadic incorrectly detected loops. When a chain has already been visited during the check, it is treated as having a standard target containing a RETURN verdict directly at the beginning in order to not check it again. The real target of the first rule is then incorrectly treated as STANDARD target and checked not to contain invalid verdicts. Fix by making sure the rule does actually contain a standard target. Based on patch by Francis Dupont Signed-off-by: Patrick McHardy Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman --- net/ipv4/netfilter/arp_tables.c | 4 +++- net/ipv4/netfilter/ip_tables.c | 4 +++- net/ipv6/netfilter/ip6_tables.c | 4 +++- 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 03e83a65aec5..6671485c60c2 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -372,7 +372,9 @@ static int mark_source_chains(struct xt_table_info *newinfo, && unconditional(&e->arp)) || visited) { unsigned int oldpos, size; - if (t->verdict < -NF_MAX_VERDICT - 1) { + if ((strcmp(t->target.u.user.name, + ARPT_STANDARD_TARGET) == 0) && + t->verdict < -NF_MAX_VERDICT - 1) { duprintf("mark_source_chains: bad " "negative verdict (%i)\n", t->verdict); diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 4e7c719445c2..b56a203e56cd 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -502,7 +502,9 @@ mark_source_chains(struct xt_table_info *newinfo, && unconditional(&e->ip)) || visited) { unsigned int oldpos, size; - if (t->verdict < -NF_MAX_VERDICT - 1) { + if ((strcmp(t->target.u.user.name, + IPT_STANDARD_TARGET) == 0) && + t->verdict < -NF_MAX_VERDICT - 1) { duprintf("mark_source_chains: bad " "negative verdict (%i)\n", t->verdict); diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 0b4557e03431..81751c36d468 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -529,7 +529,9 @@ mark_source_chains(struct xt_table_info *newinfo, && unconditional(&e->ipv6)) || visited) { unsigned int oldpos, size; - if (t->verdict < -NF_MAX_VERDICT - 1) { + if ((strcmp(t->target.u.user.name, + IP6T_STANDARD_TARGET) == 0) && + t->verdict < -NF_MAX_VERDICT - 1) { duprintf("mark_source_chains: bad " "negative verdict (%i)\n", t->verdict); -- 2.11.4.GIT