From f24e230d257af1ad7476c6e81a8dc3127a74204e Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:21 +0200
Subject: netfilter: x_tables: don't move to non-existent next rule

Ben Hawkes says:

 In the mark_source_chains function (net/ipv4/netfilter/ip_tables.c) it
 is possible for a user-supplied ipt_entry structure to have a large
 next_offset field. This field is not bounds checked prior to writing a
 counter value at the supplied offset.

Base chains enforce absolute verdict.

User defined chains are supposed to end with an unconditional return,
xtables userspace adds them automatically.

But if such return is missing we will move to non-existent next rule.

Reported-by: Ben Hawkes <hawkes@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 8 +++++---
 net/ipv4/netfilter/ip_tables.c  | 4 ++++
 2 files changed, 9 insertions(+), 3 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 4133b0f..82a434b 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -439,6 +439,8 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
 				size = e->next_offset;
 				e = (struct arpt_entry *)
 					(entry0 + pos + size);
+				if (pos + size >= newinfo->size)
+					return 0;
 				e->counters.pcnt = pos;
 				pos += size;
 			} else {
@@ -461,6 +463,8 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
 				} else {
 					/* ... this is a fallthru */
 					newpos = pos + e->next_offset;
+					if (newpos >= newinfo->size)
+						return 0;
 				}
 				e = (struct arpt_entry *)
 					(entry0 + newpos);
@@ -691,10 +695,8 @@ static int translate_table(struct xt_table_info *newinfo, void *entry0,
 		}
 	}
 
-	if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
-		duprintf("Looping hook\n");
+	if (!mark_source_chains(newinfo, repl->valid_hooks, entry0))
 		return -ELOOP;
-	}
 
 	/* Finally, each sanity check must pass */
 	i = 0;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 631c100..e301a3d 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -520,6 +520,8 @@ mark_source_chains(const struct xt_table_info *newinfo,
 				size = e->next_offset;
 				e = (struct ipt_entry *)
 					(entry0 + pos + size);
+				if (pos + size >= newinfo->size)
+					return 0;
 				e->counters.pcnt = pos;
 				pos += size;
 			} else {
@@ -541,6 +543,8 @@ mark_source_chains(const struct xt_table_info *newinfo,
 				} else {
 					/* ... this is a fallthru */
 					newpos = pos + e->next_offset;
+					if (newpos >= newinfo->size)
+						return 0;
 				}
 				e = (struct ipt_entry *)
 					(entry0 + newpos);
-- 
cgit v1.1


From 36472341017529e2b12573093cc0f68719300997 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:22 +0200
Subject: netfilter: x_tables: validate targets of jumps

When we see a jump also check that the offset gets us to beginning of
a rule (an ipt_entry).

The extra overhead is negible, even with absurd cases.

300k custom rules, 300k jumps to 'next' user chain:
[ plus one jump from INPUT to first userchain ]:

Before:
real    0m24.874s
user    0m7.532s
sys     0m16.076s

After:
real    0m27.464s
user    0m7.436s
sys     0m18.840s

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 16 ++++++++++++++++
 net/ipv4/netfilter/ip_tables.c  | 16 ++++++++++++++++
 2 files changed, 32 insertions(+)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 82a434b..ec37f7c 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -367,6 +367,18 @@ static inline bool unconditional(const struct arpt_entry *e)
 	       memcmp(&e->arp, &uncond, sizeof(uncond)) == 0;
 }
 
+static bool find_jump_target(const struct xt_table_info *t,
+			     const struct arpt_entry *target)
+{
+	struct arpt_entry *iter;
+
+	xt_entry_foreach(iter, t->entries, t->size) {
+		 if (iter == target)
+			return true;
+	}
+	return false;
+}
+
 /* Figures out from what hook each rule can be called: returns 0 if
  * there are loops.  Puts hook bitmask in comefrom.
  */
@@ -460,6 +472,10 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
 					/* This a jump; chase it. */
 					duprintf("Jump rule %u -> %u\n",
 						 pos, newpos);
+					e = (struct arpt_entry *)
+						(entry0 + newpos);
+					if (!find_jump_target(newinfo, e))
+						return 0;
 				} else {
 					/* ... this is a fallthru */
 					newpos = pos + e->next_offset;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index e301a3d..503038e 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -443,6 +443,18 @@ ipt_do_table(struct sk_buff *skb,
 #endif
 }
 
+static bool find_jump_target(const struct xt_table_info *t,
+			     const struct ipt_entry *target)
+{
+	struct ipt_entry *iter;
+
+	xt_entry_foreach(iter, t->entries, t->size) {
+		 if (iter == target)
+			return true;
+	}
+	return false;
+}
+
 /* Figures out from what hook each rule can be called: returns 0 if
    there are loops.  Puts hook bitmask in comefrom. */
 static int
@@ -540,6 +552,10 @@ mark_source_chains(const struct xt_table_info *newinfo,
 					/* This a jump; chase it. */
 					duprintf("Jump rule %u -> %u\n",
 						 pos, newpos);
+					e = (struct ipt_entry *)
+						(entry0 + newpos);
+					if (!find_jump_target(newinfo, e))
+						return 0;
 				} else {
 					/* ... this is a fallthru */
 					newpos = pos + e->next_offset;
-- 
cgit v1.1


From 7d35812c3214afa5b37a675113555259cfd67b98 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:23 +0200
Subject: netfilter: x_tables: add and use xt_check_entry_offsets

Currently arp/ip and ip6tables each implement a short helper to check that
the target offset is large enough to hold one xt_entry_target struct and
that t->u.target_size fits within the current rule.

Unfortunately these checks are not sufficient.

To avoid adding new tests to all of ip/ip6/arptables move the current
checks into a helper, then extend this helper in followup patches.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 11 +----------
 net/ipv4/netfilter/ip_tables.c  | 12 +-----------
 2 files changed, 2 insertions(+), 21 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index ec37f7c..74668c1 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -496,19 +496,10 @@ next:
 
 static inline int check_entry(const struct arpt_entry *e)
 {
-	const struct xt_entry_target *t;
-
 	if (!arp_checkentry(&e->arp))
 		return -EINVAL;
 
-	if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
-		return -EINVAL;
-
-	t = arpt_get_target_c(e);
-	if (e->target_offset + t->u.target_size > e->next_offset)
-		return -EINVAL;
-
-	return 0;
+	return xt_check_entry_offsets(e, e->target_offset, e->next_offset);
 }
 
 static inline int check_target(struct arpt_entry *e, const char *name)
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 503038e..71c204d 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -590,20 +590,10 @@ static void cleanup_match(struct xt_entry_match *m, struct net *net)
 static int
 check_entry(const struct ipt_entry *e)
 {
-	const struct xt_entry_target *t;
-
 	if (!ip_checkentry(&e->ip))
 		return -EINVAL;
 
-	if (e->target_offset + sizeof(struct xt_entry_target) >
-	    e->next_offset)
-		return -EINVAL;
-
-	t = ipt_get_target_c(e);
-	if (e->target_offset + t->u.target_size > e->next_offset)
-		return -EINVAL;
-
-	return 0;
+	return xt_check_entry_offsets(e, e->target_offset, e->next_offset);
 }
 
 static int
-- 
cgit v1.1


From aa412ba225dd3bc36d404c28cdc3d674850d80d0 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:24 +0200
Subject: netfilter: x_tables: kill check_entry helper

Once we add more sanity testing to xt_check_entry_offsets it
becomes relvant if we're expecting a 32bit 'config_compat' blob
or a normal one.

Since we already have a lot of similar-named functions (check_entry,
compat_check_entry, find_and_check_entry, etc.) and the current
incarnation is short just fold its contents into the callers.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 19 ++++++++-----------
 net/ipv4/netfilter/ip_tables.c  | 20 ++++++++------------
 2 files changed, 16 insertions(+), 23 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 74668c1..24ad92a 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -494,14 +494,6 @@ next:
 	return 1;
 }
 
-static inline int check_entry(const struct arpt_entry *e)
-{
-	if (!arp_checkentry(&e->arp))
-		return -EINVAL;
-
-	return xt_check_entry_offsets(e, e->target_offset, e->next_offset);
-}
-
 static inline int check_target(struct arpt_entry *e, const char *name)
 {
 	struct xt_entry_target *t = arpt_get_target(e);
@@ -597,7 +589,10 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e,
 		return -EINVAL;
 	}
 
-	err = check_entry(e);
+	if (!arp_checkentry(&e->arp))
+		return -EINVAL;
+
+	err = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
 	if (err)
 		return err;
 
@@ -1256,8 +1251,10 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
 		return -EINVAL;
 	}
 
-	/* For purposes of check_entry casting the compat entry is fine */
-	ret = check_entry((struct arpt_entry *)e);
+	if (!arp_checkentry(&e->arp))
+		return -EINVAL;
+
+	ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
 	if (ret)
 		return ret;
 
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 71c204d..cdf1850 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -588,15 +588,6 @@ static void cleanup_match(struct xt_entry_match *m, struct net *net)
 }
 
 static int
-check_entry(const struct ipt_entry *e)
-{
-	if (!ip_checkentry(&e->ip))
-		return -EINVAL;
-
-	return xt_check_entry_offsets(e, e->target_offset, e->next_offset);
-}
-
-static int
 check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 {
 	const struct ipt_ip *ip = par->entryinfo;
@@ -760,7 +751,10 @@ check_entry_size_and_hooks(struct ipt_entry *e,
 		return -EINVAL;
 	}
 
-	err = check_entry(e);
+	if (!ip_checkentry(&e->ip))
+		return -EINVAL;
+
+	err = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
 	if (err)
 		return err;
 
@@ -1516,8 +1510,10 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 		return -EINVAL;
 	}
 
-	/* For purposes of check_entry casting the compat entry is fine */
-	ret = check_entry((struct ipt_entry *)e);
+	if (!ip_checkentry(&e->ip))
+		return -EINVAL;
+
+	ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
 	if (ret)
 		return ret;
 
-- 
cgit v1.1


From fc1221b3a163d1386d1052184202d5dc50d302d1 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:26 +0200
Subject: netfilter: x_tables: add compat version of xt_check_entry_offsets

32bit rulesets have different layout and alignment requirements, so once
more integrity checks get added to xt_check_entry_offsets it will reject
well-formed 32bit rulesets.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 3 ++-
 net/ipv4/netfilter/ip_tables.c  | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 24ad92a..ab8952a 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1254,7 +1254,8 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
 	if (!arp_checkentry(&e->arp))
 		return -EINVAL;
 
-	ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
+	ret = xt_compat_check_entry_offsets(e, e->target_offset,
+					    e->next_offset);
 	if (ret)
 		return ret;
 
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index cdf1850..7d24c87 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1513,7 +1513,8 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 	if (!ip_checkentry(&e->ip))
 		return -EINVAL;
 
-	ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
+	ret = xt_compat_check_entry_offsets(e,
+					    e->target_offset, e->next_offset);
 	if (ret)
 		return ret;
 
-- 
cgit v1.1


From ce683e5f9d045e5d67d1312a42b359cb2ab2a13c Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:28 +0200
Subject: netfilter: x_tables: check for bogus target offset

We're currently asserting that targetoff + targetsize <= nextoff.

Extend it to also check that targetoff is >= sizeof(xt_entry).
Since this is generic code, add an argument pointing to the start of the
match/target, we can then derive the base structure size from the delta.

We also need the e->elems pointer in a followup change to validate matches.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 5 +++--
 net/ipv4/netfilter/ip_tables.c  | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index ab8952a..95ed4e4 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -592,7 +592,8 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e,
 	if (!arp_checkentry(&e->arp))
 		return -EINVAL;
 
-	err = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
+	err = xt_check_entry_offsets(e, e->elems, e->target_offset,
+				     e->next_offset);
 	if (err)
 		return err;
 
@@ -1254,7 +1255,7 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
 	if (!arp_checkentry(&e->arp))
 		return -EINVAL;
 
-	ret = xt_compat_check_entry_offsets(e, e->target_offset,
+	ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset,
 					    e->next_offset);
 	if (ret)
 		return ret;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 7d24c87..baab033d 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -754,7 +754,8 @@ check_entry_size_and_hooks(struct ipt_entry *e,
 	if (!ip_checkentry(&e->ip))
 		return -EINVAL;
 
-	err = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
+	err = xt_check_entry_offsets(e, e->elems, e->target_offset,
+				     e->next_offset);
 	if (err)
 		return err;
 
@@ -1513,7 +1514,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 	if (!ip_checkentry(&e->ip))
 		return -EINVAL;
 
-	ret = xt_compat_check_entry_offsets(e,
+	ret = xt_compat_check_entry_offsets(e, e->elems,
 					    e->target_offset, e->next_offset);
 	if (ret)
 		return ret;
-- 
cgit v1.1


From 7d3f843eed29222254c9feab481f55175a1afcc9 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:30 +0200
Subject: netfilter: ip_tables: simplify translate_compat_table args

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/ip_tables.c | 59 +++++++++++++++++-------------------------
 1 file changed, 24 insertions(+), 35 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index baab033d..d7041860 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1449,7 +1449,6 @@ compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
 
 static int
 compat_find_calc_match(struct xt_entry_match *m,
-		       const char *name,
 		       const struct ipt_ip *ip,
 		       int *size)
 {
@@ -1486,8 +1485,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 				  const unsigned char *base,
 				  const unsigned char *limit,
 				  const unsigned int *hook_entries,
-				  const unsigned int *underflows,
-				  const char *name)
+				  const unsigned int *underflows)
 {
 	struct xt_entry_match *ematch;
 	struct xt_entry_target *t;
@@ -1523,7 +1521,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 	entry_offset = (void *)e - (void *)base;
 	j = 0;
 	xt_ematch_foreach(ematch, e) {
-		ret = compat_find_calc_match(ematch, name, &e->ip, &off);
+		ret = compat_find_calc_match(ematch, &e->ip, &off);
 		if (ret != 0)
 			goto release_matches;
 		++j;
@@ -1572,7 +1570,7 @@ release_matches:
 
 static int
 compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
-			    unsigned int *size, const char *name,
+			    unsigned int *size,
 			    struct xt_table_info *newinfo, unsigned char *base)
 {
 	struct xt_entry_target *t;
@@ -1655,14 +1653,9 @@ compat_check_entry(struct ipt_entry *e, struct net *net, const char *name)
 
 static int
 translate_compat_table(struct net *net,
-		       const char *name,
-		       unsigned int valid_hooks,
 		       struct xt_table_info **pinfo,
 		       void **pentry0,
-		       unsigned int total_size,
-		       unsigned int number,
-		       unsigned int *hook_entries,
-		       unsigned int *underflows)
+		       const struct compat_ipt_replace *compatr)
 {
 	unsigned int i, j;
 	struct xt_table_info *newinfo, *info;
@@ -1674,8 +1667,8 @@ translate_compat_table(struct net *net,
 
 	info = *pinfo;
 	entry0 = *pentry0;
-	size = total_size;
-	info->number = number;
+	size = compatr->size;
+	info->number = compatr->num_entries;
 
 	/* Init all hooks to impossible value. */
 	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
@@ -1686,40 +1679,39 @@ translate_compat_table(struct net *net,
 	duprintf("translate_compat_table: size %u\n", info->size);
 	j = 0;
 	xt_compat_lock(AF_INET);
-	xt_compat_init_offsets(AF_INET, number);
+	xt_compat_init_offsets(AF_INET, compatr->num_entries);
 	/* Walk through entries, checking offsets. */
-	xt_entry_foreach(iter0, entry0, total_size) {
+	xt_entry_foreach(iter0, entry0, compatr->size) {
 		ret = check_compat_entry_size_and_hooks(iter0, info, &size,
 							entry0,
-							entry0 + total_size,
-							hook_entries,
-							underflows,
-							name);
+							entry0 + compatr->size,
+							compatr->hook_entry,
+							compatr->underflow);
 		if (ret != 0)
 			goto out_unlock;
 		++j;
 	}
 
 	ret = -EINVAL;
-	if (j != number) {
+	if (j != compatr->num_entries) {
 		duprintf("translate_compat_table: %u not %u entries\n",
-			 j, number);
+			 j, compatr->num_entries);
 		goto out_unlock;
 	}
 
 	/* Check hooks all assigned */
 	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 		/* Only hooks which are valid */
-		if (!(valid_hooks & (1 << i)))
+		if (!(compatr->valid_hooks & (1 << i)))
 			continue;
 		if (info->hook_entry[i] == 0xFFFFFFFF) {
 			duprintf("Invalid hook entry %u %u\n",
-				 i, hook_entries[i]);
+				 i, info->hook_entry[i]);
 			goto out_unlock;
 		}
 		if (info->underflow[i] == 0xFFFFFFFF) {
 			duprintf("Invalid underflow %u %u\n",
-				 i, underflows[i]);
+				 i, info->underflow[i]);
 			goto out_unlock;
 		}
 	}
@@ -1729,17 +1721,17 @@ translate_compat_table(struct net *net,
 	if (!newinfo)
 		goto out_unlock;
 
-	newinfo->number = number;
+	newinfo->number = compatr->num_entries;
 	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 		newinfo->hook_entry[i] = info->hook_entry[i];
 		newinfo->underflow[i] = info->underflow[i];
 	}
 	entry1 = newinfo->entries;
 	pos = entry1;
-	size = total_size;
-	xt_entry_foreach(iter0, entry0, total_size) {
+	size = compatr->size;
+	xt_entry_foreach(iter0, entry0, compatr->size) {
 		ret = compat_copy_entry_from_user(iter0, &pos, &size,
-						  name, newinfo, entry1);
+						  newinfo, entry1);
 		if (ret != 0)
 			break;
 	}
@@ -1749,12 +1741,12 @@ translate_compat_table(struct net *net,
 		goto free_newinfo;
 
 	ret = -ELOOP;
-	if (!mark_source_chains(newinfo, valid_hooks, entry1))
+	if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1))
 		goto free_newinfo;
 
 	i = 0;
 	xt_entry_foreach(iter1, entry1, newinfo->size) {
-		ret = compat_check_entry(iter1, net, name);
+		ret = compat_check_entry(iter1, net, compatr->name);
 		if (ret != 0)
 			break;
 		++i;
@@ -1794,7 +1786,7 @@ translate_compat_table(struct net *net,
 free_newinfo:
 	xt_free_table_info(newinfo);
 out:
-	xt_entry_foreach(iter0, entry0, total_size) {
+	xt_entry_foreach(iter0, entry0, compatr->size) {
 		if (j-- == 0)
 			break;
 		compat_release_entry(iter0);
@@ -1839,10 +1831,7 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
 		goto free_newinfo;
 	}
 
-	ret = translate_compat_table(net, tmp.name, tmp.valid_hooks,
-				     &newinfo, &loc_cpu_entry, tmp.size,
-				     tmp.num_entries, tmp.hook_entry,
-				     tmp.underflow);
+	ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
 	if (ret != 0)
 		goto free_newinfo;
 
-- 
cgit v1.1


From 8dddd32756f6fe8e4e82a63361119b7e2384e02f Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:32 +0200
Subject: netfilter: arp_tables: simplify translate_compat_table args

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 82 ++++++++++++++++++-----------------------
 1 file changed, 36 insertions(+), 46 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 95ed4e4..1d1386d 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1214,6 +1214,18 @@ static int do_add_counters(struct net *net, const void __user *user,
 }
 
 #ifdef CONFIG_COMPAT
+struct compat_arpt_replace {
+	char				name[XT_TABLE_MAXNAMELEN];
+	u32				valid_hooks;
+	u32				num_entries;
+	u32				size;
+	u32				hook_entry[NF_ARP_NUMHOOKS];
+	u32				underflow[NF_ARP_NUMHOOKS];
+	u32				num_counters;
+	compat_uptr_t			counters;
+	struct compat_arpt_entry	entries[0];
+};
+
 static inline void compat_release_entry(struct compat_arpt_entry *e)
 {
 	struct xt_entry_target *t;
@@ -1229,8 +1241,7 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
 				  const unsigned char *base,
 				  const unsigned char *limit,
 				  const unsigned int *hook_entries,
-				  const unsigned int *underflows,
-				  const char *name)
+				  const unsigned int *underflows)
 {
 	struct xt_entry_target *t;
 	struct xt_target *target;
@@ -1301,7 +1312,7 @@ out:
 
 static int
 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
-			    unsigned int *size, const char *name,
+			    unsigned int *size,
 			    struct xt_table_info *newinfo, unsigned char *base)
 {
 	struct xt_entry_target *t;
@@ -1334,14 +1345,9 @@ compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
 	return ret;
 }
 
-static int translate_compat_table(const char *name,
-				  unsigned int valid_hooks,
-				  struct xt_table_info **pinfo,
+static int translate_compat_table(struct xt_table_info **pinfo,
 				  void **pentry0,
-				  unsigned int total_size,
-				  unsigned int number,
-				  unsigned int *hook_entries,
-				  unsigned int *underflows)
+				  const struct compat_arpt_replace *compatr)
 {
 	unsigned int i, j;
 	struct xt_table_info *newinfo, *info;
@@ -1353,8 +1359,8 @@ static int translate_compat_table(const char *name,
 
 	info = *pinfo;
 	entry0 = *pentry0;
-	size = total_size;
-	info->number = number;
+	size = compatr->size;
+	info->number = compatr->num_entries;
 
 	/* Init all hooks to impossible value. */
 	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
@@ -1365,40 +1371,39 @@ static int translate_compat_table(const char *name,
 	duprintf("translate_compat_table: size %u\n", info->size);
 	j = 0;
 	xt_compat_lock(NFPROTO_ARP);
-	xt_compat_init_offsets(NFPROTO_ARP, number);
+	xt_compat_init_offsets(NFPROTO_ARP, compatr->num_entries);
 	/* Walk through entries, checking offsets. */
-	xt_entry_foreach(iter0, entry0, total_size) {
+	xt_entry_foreach(iter0, entry0, compatr->size) {
 		ret = check_compat_entry_size_and_hooks(iter0, info, &size,
 							entry0,
-							entry0 + total_size,
-							hook_entries,
-							underflows,
-							name);
+							entry0 + compatr->size,
+							compatr->hook_entry,
+							compatr->underflow);
 		if (ret != 0)
 			goto out_unlock;
 		++j;
 	}
 
 	ret = -EINVAL;
-	if (j != number) {
+	if (j != compatr->num_entries) {
 		duprintf("translate_compat_table: %u not %u entries\n",
-			 j, number);
+			 j, compatr->num_entries);
 		goto out_unlock;
 	}
 
 	/* Check hooks all assigned */
 	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 		/* Only hooks which are valid */
-		if (!(valid_hooks & (1 << i)))
+		if (!(compatr->valid_hooks & (1 << i)))
 			continue;
 		if (info->hook_entry[i] == 0xFFFFFFFF) {
 			duprintf("Invalid hook entry %u %u\n",
-				 i, hook_entries[i]);
+				 i, info->hook_entry[i]);
 			goto out_unlock;
 		}
 		if (info->underflow[i] == 0xFFFFFFFF) {
 			duprintf("Invalid underflow %u %u\n",
-				 i, underflows[i]);
+				 i, info->underflow[i]);
 			goto out_unlock;
 		}
 	}
@@ -1408,17 +1413,17 @@ static int translate_compat_table(const char *name,
 	if (!newinfo)
 		goto out_unlock;
 
-	newinfo->number = number;
+	newinfo->number = compatr->num_entries;
 	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 		newinfo->hook_entry[i] = info->hook_entry[i];
 		newinfo->underflow[i] = info->underflow[i];
 	}
 	entry1 = newinfo->entries;
 	pos = entry1;
-	size = total_size;
-	xt_entry_foreach(iter0, entry0, total_size) {
+	size = compatr->size;
+	xt_entry_foreach(iter0, entry0, compatr->size) {
 		ret = compat_copy_entry_from_user(iter0, &pos, &size,
-						  name, newinfo, entry1);
+						  newinfo, entry1);
 		if (ret != 0)
 			break;
 	}
@@ -1428,7 +1433,7 @@ static int translate_compat_table(const char *name,
 		goto free_newinfo;
 
 	ret = -ELOOP;
-	if (!mark_source_chains(newinfo, valid_hooks, entry1))
+	if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1))
 		goto free_newinfo;
 
 	i = 0;
@@ -1439,7 +1444,7 @@ static int translate_compat_table(const char *name,
 			break;
 		}
 
-		ret = check_target(iter1, name);
+		ret = check_target(iter1, compatr->name);
 		if (ret != 0) {
 			xt_percpu_counter_free(iter1->counters.pcnt);
 			break;
@@ -1481,7 +1486,7 @@ static int translate_compat_table(const char *name,
 free_newinfo:
 	xt_free_table_info(newinfo);
 out:
-	xt_entry_foreach(iter0, entry0, total_size) {
+	xt_entry_foreach(iter0, entry0, compatr->size) {
 		if (j-- == 0)
 			break;
 		compat_release_entry(iter0);
@@ -1493,18 +1498,6 @@ out_unlock:
 	goto out;
 }
 
-struct compat_arpt_replace {
-	char				name[XT_TABLE_MAXNAMELEN];
-	u32				valid_hooks;
-	u32				num_entries;
-	u32				size;
-	u32				hook_entry[NF_ARP_NUMHOOKS];
-	u32				underflow[NF_ARP_NUMHOOKS];
-	u32				num_counters;
-	compat_uptr_t			counters;
-	struct compat_arpt_entry	entries[0];
-};
-
 static int compat_do_replace(struct net *net, void __user *user,
 			     unsigned int len)
 {
@@ -1537,10 +1530,7 @@ static int compat_do_replace(struct net *net, void __user *user,
 		goto free_newinfo;
 	}
 
-	ret = translate_compat_table(tmp.name, tmp.valid_hooks,
-				     &newinfo, &loc_cpu_entry, tmp.size,
-				     tmp.num_entries, tmp.hook_entry,
-				     tmp.underflow);
+	ret = translate_compat_table(&newinfo, &loc_cpu_entry, &tmp);
 	if (ret != 0)
 		goto free_newinfo;
 
-- 
cgit v1.1


From 0188346f21e6546498c2a0f84888797ad4063fc5 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:33 +0200
Subject: netfilter: x_tables: xt_compat_match_from_user doesn't need a retval

Always returned 0.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 17 +++++------------
 net/ipv4/netfilter/ip_tables.c  | 26 +++++++++-----------------
 2 files changed, 14 insertions(+), 29 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 1d1386d..be514c6 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1310,7 +1310,7 @@ out:
 	return ret;
 }
 
-static int
+static void
 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
 			    unsigned int *size,
 			    struct xt_table_info *newinfo, unsigned char *base)
@@ -1319,9 +1319,8 @@ compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
 	struct xt_target *target;
 	struct arpt_entry *de;
 	unsigned int origsize;
-	int ret, h;
+	int h;
 
-	ret = 0;
 	origsize = *size;
 	de = (struct arpt_entry *)*dstptr;
 	memcpy(de, e, sizeof(struct arpt_entry));
@@ -1342,7 +1341,6 @@ compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
 		if ((unsigned char *)de - base < newinfo->underflow[h])
 			newinfo->underflow[h] -= origsize - *size;
 	}
-	return ret;
 }
 
 static int translate_compat_table(struct xt_table_info **pinfo,
@@ -1421,16 +1419,11 @@ static int translate_compat_table(struct xt_table_info **pinfo,
 	entry1 = newinfo->entries;
 	pos = entry1;
 	size = compatr->size;
-	xt_entry_foreach(iter0, entry0, compatr->size) {
-		ret = compat_copy_entry_from_user(iter0, &pos, &size,
-						  newinfo, entry1);
-		if (ret != 0)
-			break;
-	}
+	xt_entry_foreach(iter0, entry0, compatr->size)
+		compat_copy_entry_from_user(iter0, &pos, &size,
+					    newinfo, entry1);
 	xt_compat_flush_offsets(NFPROTO_ARP);
 	xt_compat_unlock(NFPROTO_ARP);
-	if (ret)
-		goto free_newinfo;
 
 	ret = -ELOOP;
 	if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1))
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index d7041860..5c20eef 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1568,7 +1568,7 @@ release_matches:
 	return ret;
 }
 
-static int
+static void
 compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
 			    unsigned int *size,
 			    struct xt_table_info *newinfo, unsigned char *base)
@@ -1577,10 +1577,9 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
 	struct xt_target *target;
 	struct ipt_entry *de;
 	unsigned int origsize;
-	int ret, h;
+	int h;
 	struct xt_entry_match *ematch;
 
-	ret = 0;
 	origsize = *size;
 	de = (struct ipt_entry *)*dstptr;
 	memcpy(de, e, sizeof(struct ipt_entry));
@@ -1589,11 +1588,9 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
 	*dstptr += sizeof(struct ipt_entry);
 	*size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
 
-	xt_ematch_foreach(ematch, e) {
-		ret = xt_compat_match_from_user(ematch, dstptr, size);
-		if (ret != 0)
-			return ret;
-	}
+	xt_ematch_foreach(ematch, e)
+		xt_compat_match_from_user(ematch, dstptr, size);
+
 	de->target_offset = e->target_offset - (origsize - *size);
 	t = compat_ipt_get_target(e);
 	target = t->u.kernel.target;
@@ -1606,7 +1603,6 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
 		if ((unsigned char *)de - base < newinfo->underflow[h])
 			newinfo->underflow[h] -= origsize - *size;
 	}
-	return ret;
 }
 
 static int
@@ -1729,16 +1725,12 @@ translate_compat_table(struct net *net,
 	entry1 = newinfo->entries;
 	pos = entry1;
 	size = compatr->size;
-	xt_entry_foreach(iter0, entry0, compatr->size) {
-		ret = compat_copy_entry_from_user(iter0, &pos, &size,
-						  newinfo, entry1);
-		if (ret != 0)
-			break;
-	}
+	xt_entry_foreach(iter0, entry0, compatr->size)
+		compat_copy_entry_from_user(iter0, &pos, &size,
+					    newinfo, entry1);
+
 	xt_compat_flush_offsets(AF_INET);
 	xt_compat_unlock(AF_INET);
-	if (ret)
-		goto free_newinfo;
 
 	ret = -ELOOP;
 	if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1))
-- 
cgit v1.1


From 09d9686047dbbe1cf4faa558d3ecc4aae2046054 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:34 +0200
Subject: netfilter: x_tables: do compat validation via translate_table

This looks like refactoring, but its also a bug fix.

Problem is that the compat path (32bit iptables, 64bit kernel) lacks a few
sanity tests that are done in the normal path.

For example, we do not check for underflows and the base chain policies.

While its possible to also add such checks to the compat path, its more
copy&pastry, for instance we cannot reuse check_underflow() helper as
e->target_offset differs in the compat case.

Other problem is that it makes auditing for validation errors harder; two
places need to be checked and kept in sync.

At a high level 32 bit compat works like this:
1- initial pass over blob:
   validate match/entry offsets, bounds checking
   lookup all matches and targets
   do bookkeeping wrt. size delta of 32/64bit structures
   assign match/target.u.kernel pointer (points at kernel
   implementation, needed to access ->compatsize etc.)

2- allocate memory according to the total bookkeeping size to
   contain the translated ruleset

3- second pass over original blob:
   for each entry, copy the 32bit representation to the newly allocated
   memory.  This also does any special match translations (e.g.
   adjust 32bit to 64bit longs, etc).

4- check if ruleset is free of loops (chase all jumps)

5-first pass over translated blob:
   call the checkentry function of all matches and targets.

The alternative implemented by this patch is to drop steps 3&4 from the
compat process, the translation is changed into an intermediate step
rather than a full 1:1 translate_table replacement.

In the 2nd pass (step #3), change the 64bit ruleset back to a kernel
representation, i.e. put() the kernel pointer and restore ->u.user.name .

This gets us a 64bit ruleset that is in the format generated by a 64bit
iptables userspace -- we can then use translate_table() to get the
'native' sanity checks.

This has two drawbacks:

1. we re-validate all the match and target entry structure sizes even
though compat translation is supposed to never generate bogus offsets.
2. we put and then re-lookup each match and target.

THe upside is that we get all sanity tests and ruleset validations
provided by the normal path and can remove some duplicated compat code.

iptables-restore time of autogenerated ruleset with 300k chains of form
-A CHAIN0001 -m limit --limit 1/s -j CHAIN0002
-A CHAIN0002 -m limit --limit 1/s -j CHAIN0003

shows no noticeable differences in restore times:
old:   0m30.796s
new:   0m31.521s
64bit: 0m25.674s

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 114 ++++++-----------------------
 net/ipv4/netfilter/ip_tables.c  | 155 ++++++++--------------------------------
 2 files changed, 52 insertions(+), 217 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index be514c6..705179b 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1234,19 +1234,17 @@ static inline void compat_release_entry(struct compat_arpt_entry *e)
 	module_put(t->u.kernel.target->me);
 }
 
-static inline int
+static int
 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
 				  struct xt_table_info *newinfo,
 				  unsigned int *size,
 				  const unsigned char *base,
-				  const unsigned char *limit,
-				  const unsigned int *hook_entries,
-				  const unsigned int *underflows)
+				  const unsigned char *limit)
 {
 	struct xt_entry_target *t;
 	struct xt_target *target;
 	unsigned int entry_offset;
-	int ret, off, h;
+	int ret, off;
 
 	duprintf("check_compat_entry_size_and_hooks %p\n", e);
 	if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
@@ -1291,17 +1289,6 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
 	if (ret)
 		goto release_target;
 
-	/* Check hooks & underflows */
-	for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
-		if ((unsigned char *)e - base == hook_entries[h])
-			newinfo->hook_entry[h] = hook_entries[h];
-		if ((unsigned char *)e - base == underflows[h])
-			newinfo->underflow[h] = underflows[h];
-	}
-
-	/* Clear counters and comefrom */
-	memset(&e->counters, 0, sizeof(e->counters));
-	e->comefrom = 0;
 	return 0;
 
 release_target:
@@ -1351,7 +1338,7 @@ static int translate_compat_table(struct xt_table_info **pinfo,
 	struct xt_table_info *newinfo, *info;
 	void *pos, *entry0, *entry1;
 	struct compat_arpt_entry *iter0;
-	struct arpt_entry *iter1;
+	struct arpt_replace repl;
 	unsigned int size;
 	int ret = 0;
 
@@ -1360,12 +1347,6 @@ static int translate_compat_table(struct xt_table_info **pinfo,
 	size = compatr->size;
 	info->number = compatr->num_entries;
 
-	/* Init all hooks to impossible value. */
-	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
-		info->hook_entry[i] = 0xFFFFFFFF;
-		info->underflow[i] = 0xFFFFFFFF;
-	}
-
 	duprintf("translate_compat_table: size %u\n", info->size);
 	j = 0;
 	xt_compat_lock(NFPROTO_ARP);
@@ -1374,9 +1355,7 @@ static int translate_compat_table(struct xt_table_info **pinfo,
 	xt_entry_foreach(iter0, entry0, compatr->size) {
 		ret = check_compat_entry_size_and_hooks(iter0, info, &size,
 							entry0,
-							entry0 + compatr->size,
-							compatr->hook_entry,
-							compatr->underflow);
+							entry0 + compatr->size);
 		if (ret != 0)
 			goto out_unlock;
 		++j;
@@ -1389,23 +1368,6 @@ static int translate_compat_table(struct xt_table_info **pinfo,
 		goto out_unlock;
 	}
 
-	/* Check hooks all assigned */
-	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
-		/* Only hooks which are valid */
-		if (!(compatr->valid_hooks & (1 << i)))
-			continue;
-		if (info->hook_entry[i] == 0xFFFFFFFF) {
-			duprintf("Invalid hook entry %u %u\n",
-				 i, info->hook_entry[i]);
-			goto out_unlock;
-		}
-		if (info->underflow[i] == 0xFFFFFFFF) {
-			duprintf("Invalid underflow %u %u\n",
-				 i, info->underflow[i]);
-			goto out_unlock;
-		}
-	}
-
 	ret = -ENOMEM;
 	newinfo = xt_alloc_table_info(size);
 	if (!newinfo)
@@ -1422,55 +1384,26 @@ static int translate_compat_table(struct xt_table_info **pinfo,
 	xt_entry_foreach(iter0, entry0, compatr->size)
 		compat_copy_entry_from_user(iter0, &pos, &size,
 					    newinfo, entry1);
+
+	/* all module references in entry0 are now gone */
+
 	xt_compat_flush_offsets(NFPROTO_ARP);
 	xt_compat_unlock(NFPROTO_ARP);
 
-	ret = -ELOOP;
-	if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1))
-		goto free_newinfo;
-
-	i = 0;
-	xt_entry_foreach(iter1, entry1, newinfo->size) {
-		iter1->counters.pcnt = xt_percpu_counter_alloc();
-		if (IS_ERR_VALUE(iter1->counters.pcnt)) {
-			ret = -ENOMEM;
-			break;
-		}
+	memcpy(&repl, compatr, sizeof(*compatr));
 
-		ret = check_target(iter1, compatr->name);
-		if (ret != 0) {
-			xt_percpu_counter_free(iter1->counters.pcnt);
-			break;
-		}
-		++i;
-		if (strcmp(arpt_get_target(iter1)->u.user.name,
-		    XT_ERROR_TARGET) == 0)
-			++newinfo->stacksize;
-	}
-	if (ret) {
-		/*
-		 * The first i matches need cleanup_entry (calls ->destroy)
-		 * because they had called ->check already. The other j-i
-		 * entries need only release.
-		 */
-		int skip = i;
-		j -= i;
-		xt_entry_foreach(iter0, entry0, newinfo->size) {
-			if (skip-- > 0)
-				continue;
-			if (j-- == 0)
-				break;
-			compat_release_entry(iter0);
-		}
-		xt_entry_foreach(iter1, entry1, newinfo->size) {
-			if (i-- == 0)
-				break;
-			cleanup_entry(iter1);
-		}
-		xt_free_table_info(newinfo);
-		return ret;
+	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+		repl.hook_entry[i] = newinfo->hook_entry[i];
+		repl.underflow[i] = newinfo->underflow[i];
 	}
 
+	repl.num_counters = 0;
+	repl.counters = NULL;
+	repl.size = newinfo->size;
+	ret = translate_table(newinfo, entry1, &repl);
+	if (ret)
+		goto free_newinfo;
+
 	*pinfo = newinfo;
 	*pentry0 = entry1;
 	xt_free_table_info(info);
@@ -1478,17 +1411,16 @@ static int translate_compat_table(struct xt_table_info **pinfo,
 
 free_newinfo:
 	xt_free_table_info(newinfo);
-out:
+	return ret;
+out_unlock:
+	xt_compat_flush_offsets(NFPROTO_ARP);
+	xt_compat_unlock(NFPROTO_ARP);
 	xt_entry_foreach(iter0, entry0, compatr->size) {
 		if (j-- == 0)
 			break;
 		compat_release_entry(iter0);
 	}
 	return ret;
-out_unlock:
-	xt_compat_flush_offsets(NFPROTO_ARP);
-	xt_compat_unlock(NFPROTO_ARP);
-	goto out;
 }
 
 static int compat_do_replace(struct net *net, void __user *user,
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 5c20eef..c26ccd8 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1483,16 +1483,14 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 				  struct xt_table_info *newinfo,
 				  unsigned int *size,
 				  const unsigned char *base,
-				  const unsigned char *limit,
-				  const unsigned int *hook_entries,
-				  const unsigned int *underflows)
+				  const unsigned char *limit)
 {
 	struct xt_entry_match *ematch;
 	struct xt_entry_target *t;
 	struct xt_target *target;
 	unsigned int entry_offset;
 	unsigned int j;
-	int ret, off, h;
+	int ret, off;
 
 	duprintf("check_compat_entry_size_and_hooks %p\n", e);
 	if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
@@ -1544,17 +1542,6 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 	if (ret)
 		goto out;
 
-	/* Check hooks & underflows */
-	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
-		if ((unsigned char *)e - base == hook_entries[h])
-			newinfo->hook_entry[h] = hook_entries[h];
-		if ((unsigned char *)e - base == underflows[h])
-			newinfo->underflow[h] = underflows[h];
-	}
-
-	/* Clear counters and comefrom */
-	memset(&e->counters, 0, sizeof(e->counters));
-	e->comefrom = 0;
 	return 0;
 
 out:
@@ -1597,6 +1584,7 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
 	xt_compat_target_from_user(t, dstptr, size);
 
 	de->next_offset = e->next_offset - (origsize - *size);
+
 	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
 		if ((unsigned char *)de - base < newinfo->hook_entry[h])
 			newinfo->hook_entry[h] -= origsize - *size;
@@ -1606,48 +1594,6 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
 }
 
 static int
-compat_check_entry(struct ipt_entry *e, struct net *net, const char *name)
-{
-	struct xt_entry_match *ematch;
-	struct xt_mtchk_param mtpar;
-	unsigned int j;
-	int ret = 0;
-
-	e->counters.pcnt = xt_percpu_counter_alloc();
-	if (IS_ERR_VALUE(e->counters.pcnt))
-		return -ENOMEM;
-
-	j = 0;
-	mtpar.net	= net;
-	mtpar.table     = name;
-	mtpar.entryinfo = &e->ip;
-	mtpar.hook_mask = e->comefrom;
-	mtpar.family    = NFPROTO_IPV4;
-	xt_ematch_foreach(ematch, e) {
-		ret = check_match(ematch, &mtpar);
-		if (ret != 0)
-			goto cleanup_matches;
-		++j;
-	}
-
-	ret = check_target(e, net, name);
-	if (ret)
-		goto cleanup_matches;
-	return 0;
-
- cleanup_matches:
-	xt_ematch_foreach(ematch, e) {
-		if (j-- == 0)
-			break;
-		cleanup_match(ematch, net);
-	}
-
-	xt_percpu_counter_free(e->counters.pcnt);
-
-	return ret;
-}
-
-static int
 translate_compat_table(struct net *net,
 		       struct xt_table_info **pinfo,
 		       void **pentry0,
@@ -1657,7 +1603,7 @@ translate_compat_table(struct net *net,
 	struct xt_table_info *newinfo, *info;
 	void *pos, *entry0, *entry1;
 	struct compat_ipt_entry *iter0;
-	struct ipt_entry *iter1;
+	struct ipt_replace repl;
 	unsigned int size;
 	int ret;
 
@@ -1666,12 +1612,6 @@ translate_compat_table(struct net *net,
 	size = compatr->size;
 	info->number = compatr->num_entries;
 
-	/* Init all hooks to impossible value. */
-	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
-		info->hook_entry[i] = 0xFFFFFFFF;
-		info->underflow[i] = 0xFFFFFFFF;
-	}
-
 	duprintf("translate_compat_table: size %u\n", info->size);
 	j = 0;
 	xt_compat_lock(AF_INET);
@@ -1680,9 +1620,7 @@ translate_compat_table(struct net *net,
 	xt_entry_foreach(iter0, entry0, compatr->size) {
 		ret = check_compat_entry_size_and_hooks(iter0, info, &size,
 							entry0,
-							entry0 + compatr->size,
-							compatr->hook_entry,
-							compatr->underflow);
+							entry0 + compatr->size);
 		if (ret != 0)
 			goto out_unlock;
 		++j;
@@ -1695,23 +1633,6 @@ translate_compat_table(struct net *net,
 		goto out_unlock;
 	}
 
-	/* Check hooks all assigned */
-	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
-		/* Only hooks which are valid */
-		if (!(compatr->valid_hooks & (1 << i)))
-			continue;
-		if (info->hook_entry[i] == 0xFFFFFFFF) {
-			duprintf("Invalid hook entry %u %u\n",
-				 i, info->hook_entry[i]);
-			goto out_unlock;
-		}
-		if (info->underflow[i] == 0xFFFFFFFF) {
-			duprintf("Invalid underflow %u %u\n",
-				 i, info->underflow[i]);
-			goto out_unlock;
-		}
-	}
-
 	ret = -ENOMEM;
 	newinfo = xt_alloc_table_info(size);
 	if (!newinfo)
@@ -1719,8 +1640,8 @@ translate_compat_table(struct net *net,
 
 	newinfo->number = compatr->num_entries;
 	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
-		newinfo->hook_entry[i] = info->hook_entry[i];
-		newinfo->underflow[i] = info->underflow[i];
+		newinfo->hook_entry[i] = compatr->hook_entry[i];
+		newinfo->underflow[i] = compatr->underflow[i];
 	}
 	entry1 = newinfo->entries;
 	pos = entry1;
@@ -1729,47 +1650,30 @@ translate_compat_table(struct net *net,
 		compat_copy_entry_from_user(iter0, &pos, &size,
 					    newinfo, entry1);
 
+	/* all module references in entry0 are now gone.
+	 * entry1/newinfo contains a 64bit ruleset that looks exactly as
+	 * generated by 64bit userspace.
+	 *
+	 * Call standard translate_table() to validate all hook_entrys,
+	 * underflows, check for loops, etc.
+	 */
 	xt_compat_flush_offsets(AF_INET);
 	xt_compat_unlock(AF_INET);
 
-	ret = -ELOOP;
-	if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1))
-		goto free_newinfo;
+	memcpy(&repl, compatr, sizeof(*compatr));
 
-	i = 0;
-	xt_entry_foreach(iter1, entry1, newinfo->size) {
-		ret = compat_check_entry(iter1, net, compatr->name);
-		if (ret != 0)
-			break;
-		++i;
-		if (strcmp(ipt_get_target(iter1)->u.user.name,
-		    XT_ERROR_TARGET) == 0)
-			++newinfo->stacksize;
-	}
-	if (ret) {
-		/*
-		 * The first i matches need cleanup_entry (calls ->destroy)
-		 * because they had called ->check already. The other j-i
-		 * entries need only release.
-		 */
-		int skip = i;
-		j -= i;
-		xt_entry_foreach(iter0, entry0, newinfo->size) {
-			if (skip-- > 0)
-				continue;
-			if (j-- == 0)
-				break;
-			compat_release_entry(iter0);
-		}
-		xt_entry_foreach(iter1, entry1, newinfo->size) {
-			if (i-- == 0)
-				break;
-			cleanup_entry(iter1, net);
-		}
-		xt_free_table_info(newinfo);
-		return ret;
+	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
+		repl.hook_entry[i] = newinfo->hook_entry[i];
+		repl.underflow[i] = newinfo->underflow[i];
 	}
 
+	repl.num_counters = 0;
+	repl.counters = NULL;
+	repl.size = newinfo->size;
+	ret = translate_table(net, newinfo, entry1, &repl);
+	if (ret)
+		goto free_newinfo;
+
 	*pinfo = newinfo;
 	*pentry0 = entry1;
 	xt_free_table_info(info);
@@ -1777,17 +1681,16 @@ translate_compat_table(struct net *net,
 
 free_newinfo:
 	xt_free_table_info(newinfo);
-out:
+	return ret;
+out_unlock:
+	xt_compat_flush_offsets(AF_INET);
+	xt_compat_unlock(AF_INET);
 	xt_entry_foreach(iter0, entry0, compatr->size) {
 		if (j-- == 0)
 			break;
 		compat_release_entry(iter0);
 	}
 	return ret;
-out_unlock:
-	xt_compat_flush_offsets(AF_INET);
-	xt_compat_unlock(AF_INET);
-	goto out;
 }
 
 static int
-- 
cgit v1.1


From 95609155d7fa08cc2e71d494acad39f72f0b4495 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:35 +0200
Subject: netfilter: x_tables: remove obsolete overflow check for compat case
 too

commit 9e67d5a739327c44885adebb4f3a538050be73e4
("[NETFILTER]: x_tables: remove obsolete overflow check") left the
compat parts alone, but we can kill it there as well.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 2 --
 net/ipv4/netfilter/ip_tables.c  | 2 --
 2 files changed, 4 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 705179b..668c5dc 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1436,8 +1436,6 @@ static int compat_do_replace(struct net *net, void __user *user,
 		return -EFAULT;
 
 	/* overflow check */
-	if (tmp.size >= INT_MAX / num_possible_cpus())
-		return -ENOMEM;
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
 	if (tmp.num_counters == 0)
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index c26ccd8..4585aa7 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1706,8 +1706,6 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
 		return -EFAULT;
 
 	/* overflow check */
-	if (tmp.size >= INT_MAX / num_possible_cpus())
-		return -ENOMEM;
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
 	if (tmp.num_counters == 0)
-- 
cgit v1.1


From aded9f3e9fa8db559c5b7661bbb497754270e754 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 14:17:36 +0200
Subject: netfilter: x_tables: remove obsolete check

Since 'netfilter: x_tables: validate targets of jumps' change we
validate that the target aligns exactly with beginning of a rule,
so offset test is now redundant.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 8 --------
 net/ipv4/netfilter/ip_tables.c  | 7 -------
 2 files changed, 15 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 668c5dc..8cefb7a 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -461,14 +461,6 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
 				if (strcmp(t->target.u.user.name,
 					   XT_STANDARD_TARGET) == 0 &&
 				    newpos >= 0) {
-					if (newpos > newinfo->size -
-						sizeof(struct arpt_entry)) {
-						duprintf("mark_source_chains: "
-							"bad verdict (%i)\n",
-								newpos);
-						return 0;
-					}
-
 					/* This a jump; chase it. */
 					duprintf("Jump rule %u -> %u\n",
 						 pos, newpos);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 4585aa7..9340ce0 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -542,13 +542,6 @@ mark_source_chains(const struct xt_table_info *newinfo,
 				if (strcmp(t->target.u.user.name,
 					   XT_STANDARD_TARGET) == 0 &&
 				    newpos >= 0) {
-					if (newpos > newinfo->size -
-						sizeof(struct ipt_entry)) {
-						duprintf("mark_source_chains: "
-							"bad verdict (%i)\n",
-								newpos);
-						return 0;
-					}
 					/* This a jump; chase it. */
 					duprintf("Jump rule %u -> %u\n",
 						 pos, newpos);
-- 
cgit v1.1


From d7591f0c41ce3e67600a982bab6989ef0f07b3ce Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 15:37:59 +0200
Subject: netfilter: x_tables: introduce and use xt_copy_counters_from_user

The three variants use same copy&pasted code, condense this into a
helper and use that.

Make sure info.name is 0-terminated.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/arp_tables.c | 48 +++++------------------------------------
 net/ipv4/netfilter/ip_tables.c  | 48 +++++------------------------------------
 2 files changed, 10 insertions(+), 86 deletions(-)

(limited to 'net/ipv4')

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 8cefb7a..60f5161 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1123,55 +1123,17 @@ static int do_add_counters(struct net *net, const void __user *user,
 	unsigned int i;
 	struct xt_counters_info tmp;
 	struct xt_counters *paddc;
-	unsigned int num_counters;
-	const char *name;
-	int size;
-	void *ptmp;
 	struct xt_table *t;
 	const struct xt_table_info *private;
 	int ret = 0;
 	struct arpt_entry *iter;
 	unsigned int addend;
-#ifdef CONFIG_COMPAT
-	struct compat_xt_counters_info compat_tmp;
-
-	if (compat) {
-		ptmp = &compat_tmp;
-		size = sizeof(struct compat_xt_counters_info);
-	} else
-#endif
-	{
-		ptmp = &tmp;
-		size = sizeof(struct xt_counters_info);
-	}
 
-	if (copy_from_user(ptmp, user, size) != 0)
-		return -EFAULT;
-
-#ifdef CONFIG_COMPAT
-	if (compat) {
-		num_counters = compat_tmp.num_counters;
-		name = compat_tmp.name;
-	} else
-#endif
-	{
-		num_counters = tmp.num_counters;
-		name = tmp.name;
-	}
-
-	if (len != size + num_counters * sizeof(struct xt_counters))
-		return -EINVAL;
-
-	paddc = vmalloc(len - size);
-	if (!paddc)
-		return -ENOMEM;
-
-	if (copy_from_user(paddc, user + size, len - size) != 0) {
-		ret = -EFAULT;
-		goto free;
-	}
+	paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
+	if (IS_ERR(paddc))
+		return PTR_ERR(paddc);
 
-	t = xt_find_table_lock(net, NFPROTO_ARP, name);
+	t = xt_find_table_lock(net, NFPROTO_ARP, tmp.name);
 	if (IS_ERR_OR_NULL(t)) {
 		ret = t ? PTR_ERR(t) : -ENOENT;
 		goto free;
@@ -1179,7 +1141,7 @@ static int do_add_counters(struct net *net, const void __user *user,
 
 	local_bh_disable();
 	private = t->private;
-	if (private->number != num_counters) {
+	if (private->number != tmp.num_counters) {
 		ret = -EINVAL;
 		goto unlock_up_free;
 	}
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 9340ce0..735d1ee 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1307,55 +1307,17 @@ do_add_counters(struct net *net, const void __user *user,
 	unsigned int i;
 	struct xt_counters_info tmp;
 	struct xt_counters *paddc;
-	unsigned int num_counters;
-	const char *name;
-	int size;
-	void *ptmp;
 	struct xt_table *t;
 	const struct xt_table_info *private;
 	int ret = 0;
 	struct ipt_entry *iter;
 	unsigned int addend;
-#ifdef CONFIG_COMPAT
-	struct compat_xt_counters_info compat_tmp;
-
-	if (compat) {
-		ptmp = &compat_tmp;
-		size = sizeof(struct compat_xt_counters_info);
-	} else
-#endif
-	{
-		ptmp = &tmp;
-		size = sizeof(struct xt_counters_info);
-	}
 
-	if (copy_from_user(ptmp, user, size) != 0)
-		return -EFAULT;
-
-#ifdef CONFIG_COMPAT
-	if (compat) {
-		num_counters = compat_tmp.num_counters;
-		name = compat_tmp.name;
-	} else
-#endif
-	{
-		num_counters = tmp.num_counters;
-		name = tmp.name;
-	}
-
-	if (len != size + num_counters * sizeof(struct xt_counters))
-		return -EINVAL;
-
-	paddc = vmalloc(len - size);
-	if (!paddc)
-		return -ENOMEM;
-
-	if (copy_from_user(paddc, user + size, len - size) != 0) {
-		ret = -EFAULT;
-		goto free;
-	}
+	paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
+	if (IS_ERR(paddc))
+		return PTR_ERR(paddc);
 
-	t = xt_find_table_lock(net, AF_INET, name);
+	t = xt_find_table_lock(net, AF_INET, tmp.name);
 	if (IS_ERR_OR_NULL(t)) {
 		ret = t ? PTR_ERR(t) : -ENOENT;
 		goto free;
@@ -1363,7 +1325,7 @@ do_add_counters(struct net *net, const void __user *user,
 
 	local_bh_disable();
 	private = t->private;
-	if (private->number != num_counters) {
+	if (private->number != tmp.num_counters) {
 		ret = -EINVAL;
 		goto unlock_up_free;
 	}
-- 
cgit v1.1