Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Fix endianness issue in flowtable TCP flags dissector,
   from Arnd Bergmann.

2) Extend flowtable test script with dnat rules, from Florian Westphal.

3) Reject padding in ebtables user entries and validate computed user
   offset, reported by syzbot, from Florian Westphal.

4) Fix endianness in nft_tproxy, from Phil Sutter.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 17 deletions

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 4096d8a74a2b..e1256e03a9a8 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1867,7 +1867,7 @@ static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
 }
 
 static int ebt_buf_add(struct ebt_entries_buf_state *state,
-		       void *data, unsigned int sz)
+		       const void *data, unsigned int sz)
 {
 	if (state->buf_kern_start == NULL)
 		goto count_only;
@@ -1901,7 +1901,7 @@ enum compat_mwt {
 	EBT_COMPAT_TARGET,
 };
 
-static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
+static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt,
 				enum compat_mwt compat_mwt,
 				struct ebt_entries_buf_state *state,
 				const unsigned char *base)
@@ -1979,22 +1979,23 @@ static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
 /* return size of all matches, watchers or target, including necessary
  * alignment and padding.
  */
-static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
+static int ebt_size_mwt(const struct compat_ebt_entry_mwt *match32,
 			unsigned int size_left, enum compat_mwt type,
 			struct ebt_entries_buf_state *state, const void *base)
 {
+	const char *buf = (const char *)match32;
 	int growth = 0;
-	char *buf;
 
 	if (size_left == 0)
 		return 0;
 
-	buf = (char *) match32;
-
-	while (size_left >= sizeof(*match32)) {
+	do {
 		struct ebt_entry_match *match_kern;
 		int ret;
 
+		if (size_left < sizeof(*match32))
+			return -EINVAL;
+
 		match_kern = (struct ebt_entry_match *) state->buf_kern_start;
 		if (match_kern) {
 			char *tmp;
@@ -2031,22 +2032,18 @@ static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
 		if (match_kern)
 			match_kern->match_size = ret;
 
-		/* rule should have no remaining data after target */
-		if (type == EBT_COMPAT_TARGET && size_left)
-			return -EINVAL;
-
 		match32 = (struct compat_ebt_entry_mwt *) buf;
-	}
+	} while (size_left);
 
 	return growth;
 }
 
 /* called for all ebt_entry structures. */
-static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
+static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *base,
 			  unsigned int *total,
 			  struct ebt_entries_buf_state *state)
 {
-	unsigned int i, j, startoff, new_offset = 0;
+	unsigned int i, j, startoff, next_expected_off, new_offset = 0;
 	/* stores match/watchers/targets & offset of next struct ebt_entry: */
 	unsigned int offsets[4];
 	unsigned int *offsets_update = NULL;
@@ -2132,11 +2129,13 @@ static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
 			return ret;
 	}
 
-	startoff = state->buf_user_offset - startoff;
+	next_expected_off = state->buf_user_offset - startoff;
+	if (next_expected_off != entry->next_offset)
+		return -EINVAL;
 
-	if (WARN_ON(*total < startoff))
+	if (*total < entry->next_offset)
 		return -EINVAL;
-	*total -= startoff;
+	*total -= entry->next_offset;
 	return 0;
 }