diff mbox series

[2/5] netfilter: ebtables: fix erroneous reject of last rule

Message ID 20180312161604.3060-3-pablo@netfilter.org
State Accepted, archived
Delegated to: David Miller
Headers show
Series [1/5] netfilter: nft_set_hash: skip fixed hash if timeout is specified | expand

Commit Message

Pablo Neira Ayuso March 12, 2018, 4:16 p.m. UTC 
From: Florian Westphal <fw@strlen.de>

The last rule in the blob has next_entry offset that is same as total size.
This made "ebtables32 -A OUTPUT -d de:ad:be:ef:01:02" fail on 64 bit kernel.

Fixes: b71812168571fa ("netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/bridge/netfilter/ebtables.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 254ef9f49567..a94d23b0a9af 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -2119,8 +2119,12 @@  static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
 	 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
 	 */
 	for (i = 0; i < 4 ; ++i) {
-		if (offsets[i] >= *total)
+		if (offsets[i] > *total)
 			return -EINVAL;
+
+		if (i < 3 && offsets[i] == *total)
+			return -EINVAL;
+
 		if (i == 0)
 			continue;
 		if (offsets[i-1] > offsets[i])