| Message ID | 20180308115419.20356-1-fw@strlen.de |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | [nf] netfilter: ebtables: fix erroneous reject of last rule | expand |
On Thu, Mar 08, 2018 at 12:54:19PM +0100, Florian Westphal wrote: > 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. Also applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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])
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> --- net/bridge/netfilter/ebtables.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)