ebtables: arpreply: Add the standard target sanity check
authorGao Feng <gfree.wind@vip.163.com>
Tue, 16 May 2017 01:30:18 +0000 (09:30 +0800)
committerPablo Neira Ayuso <pablo@netfilter.org>
Tue, 16 May 2017 08:24:27 +0000 (10:24 +0200)
commitc953d63548207a085abcb12a15fefc8a11ffdf0a
tree9c1ef86d8bff6836bfb73e25af1f606f96f9044f
parent591054469b3eef34bc097c30fae8ededddf8d796
ebtables: arpreply: Add the standard target sanity check

The info->target comes from userspace and it would be used directly.
So we need to add the sanity check to make sure it is a valid standard
target, although the ebtables tool has already checked it. Kernel needs
to validate anything coming from userspace.

If the target is set as an evil value, it would break the ebtables
and cause a panic. Because the non-standard target is treated as one
offset.

Now add one helper function ebt_invalid_target, and we would replace
the macro INVALID_TARGET later.

Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
include/linux/netfilter_bridge/ebtables.h
net/bridge/netfilter/ebt_arpreply.c