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Date: Fri, 30 Mar 2018 13:46:18 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 46/47] Revert "netfilter: x_tables: ensure last rule in base chain matches underflow/policy"
From: Florian Westphal <fw@...len.de>
This reverts commit 0d7df906a0e78079a02108b06d32c3ef2238ad25.
Valdis Kletnieks reported that xtables is broken in linux-next since
0d7df906a0e78 ("netfilter: x_tables: ensure last rule in base chain
matches underflow/policy"), as kernel rejects the (well-formed) ruleset:
[ 64.402790] ip6_tables: last base chain position 1136 doesn't match underflow 1344 (hook 1)
mark_source_chains is not the correct place for such a check, as it
terminates evaluation of a chain once it sees an unconditional verdict
(following rules are known to be unreachable). It seems preferrable to
fix libiptc instead, so remove this check again.
Fixes: 0d7df906a0e78 ("netfilter: x_tables: ensure last rule in base chain matches underflow/policy")
Reported-by: Valdis Kletnieks <valdis.kletnieks@...edu>
Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
net/ipv4/netfilter/arp_tables.c | 17 +----------------
net/ipv4/netfilter/ip_tables.c | 17 +----------------
net/ipv6/netfilter/ip6_tables.c | 17 +----------------
3 files changed, 3 insertions(+), 48 deletions(-)
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index f366ff1cfc19..aaafdbd15ad3 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -309,13 +309,10 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
unsigned int pos = newinfo->hook_entry[hook];
struct arpt_entry *e = entry0 + pos;
- unsigned int last_pos, depth;
if (!(valid_hooks & (1 << hook)))
continue;
- depth = 0;
- last_pos = pos;
/* Set initial back pointer. */
e->counters.pcnt = pos;
@@ -346,8 +343,6 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
pos = e->counters.pcnt;
e->counters.pcnt = 0;
- if (depth)
- --depth;
/* We're at the start. */
if (pos == oldpos)
goto next;
@@ -372,9 +367,6 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
if (!xt_find_jump_offset(offsets, newpos,
newinfo->number))
return 0;
-
- if (entry0 + newpos != arpt_next_entry(e))
- ++depth;
} else {
/* ... this is a fallthru */
newpos = pos + e->next_offset;
@@ -385,15 +377,8 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
e->counters.pcnt = pos;
pos = newpos;
}
- if (depth == 0)
- last_pos = pos;
- }
-next:
- if (last_pos != newinfo->underflow[hook]) {
- pr_err_ratelimited("last base chain position %u doesn't match underflow %u (hook %u)\n",
- last_pos, newinfo->underflow[hook], hook);
- return 0;
}
+next: ;
}
return 1;
}
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 2362ca2c9e0c..f9063513f9d1 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -378,13 +378,10 @@ mark_source_chains(const struct xt_table_info *newinfo,
for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
unsigned int pos = newinfo->hook_entry[hook];
struct ipt_entry *e = entry0 + pos;
- unsigned int last_pos, depth;
if (!(valid_hooks & (1 << hook)))
continue;
- depth = 0;
- last_pos = pos;
/* Set initial back pointer. */
e->counters.pcnt = pos;
@@ -413,8 +410,6 @@ mark_source_chains(const struct xt_table_info *newinfo,
pos = e->counters.pcnt;
e->counters.pcnt = 0;
- if (depth)
- --depth;
/* We're at the start. */
if (pos == oldpos)
goto next;
@@ -439,9 +434,6 @@ mark_source_chains(const struct xt_table_info *newinfo,
if (!xt_find_jump_offset(offsets, newpos,
newinfo->number))
return 0;
-
- if (entry0 + newpos != ipt_next_entry(e))
- ++depth;
} else {
/* ... this is a fallthru */
newpos = pos + e->next_offset;
@@ -452,15 +444,8 @@ mark_source_chains(const struct xt_table_info *newinfo,
e->counters.pcnt = pos;
pos = newpos;
}
- if (depth == 0)
- last_pos = pos;
- }
-next:
- if (last_pos != newinfo->underflow[hook]) {
- pr_err_ratelimited("last base chain position %u doesn't match underflow %u (hook %u)\n",
- last_pos, newinfo->underflow[hook], hook);
- return 0;
}
+next: ;
}
return 1;
}
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 004508753abc..3c36a4c77f29 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -396,13 +396,10 @@ mark_source_chains(const struct xt_table_info *newinfo,
for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
unsigned int pos = newinfo->hook_entry[hook];
struct ip6t_entry *e = entry0 + pos;
- unsigned int last_pos, depth;
if (!(valid_hooks & (1 << hook)))
continue;
- depth = 0;
- last_pos = pos;
/* Set initial back pointer. */
e->counters.pcnt = pos;
@@ -431,8 +428,6 @@ mark_source_chains(const struct xt_table_info *newinfo,
pos = e->counters.pcnt;
e->counters.pcnt = 0;
- if (depth)
- --depth;
/* We're at the start. */
if (pos == oldpos)
goto next;
@@ -457,9 +452,6 @@ mark_source_chains(const struct xt_table_info *newinfo,
if (!xt_find_jump_offset(offsets, newpos,
newinfo->number))
return 0;
-
- if (entry0 + newpos != ip6t_next_entry(e))
- ++depth;
} else {
/* ... this is a fallthru */
newpos = pos + e->next_offset;
@@ -470,15 +462,8 @@ mark_source_chains(const struct xt_table_info *newinfo,
e->counters.pcnt = pos;
pos = newpos;
}
- if (depth == 0)
- last_pos = pos;
- }
-next:
- if (last_pos != newinfo->underflow[hook]) {
- pr_err_ratelimited("last base chain position %u doesn't match underflow %u (hook %u)\n",
- last_pos, newinfo->underflow[hook], hook);
- return 0;
}
+next: ;
}
return 1;
}
--
2.11.0
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