Sasha Levin
2020-Jan-16 17:21 UTC
[Bridge] [PATCH AUTOSEL 4.14 197/371] netfilter: ebtables: CONFIG_COMPAT: reject trailing data after last rule
From: Florian Westphal <fw at strlen.de> [ Upstream commit 680f6af5337c98d116e4f127cea7845339dba8da ] If userspace provides a rule blob with trailing data after last target, we trigger a splat, then convert ruleset to 64bit format (with trailing data), then pass that to do_replace_finish() which then returns -EINVAL. Erroring out right away avoids the splat plus unneeded translation and error unwind. Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support") Reported-by: Tetsuo Handa <penguin-kernel at i-love.sakura.ne.jp> Signed-off-by: Florian Westphal <fw at strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org> Signed-off-by: Sasha Levin <sashal at kernel.org> --- net/bridge/netfilter/ebtables.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 35a670ec9077..a1834ad7422c 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -2164,7 +2164,9 @@ static int compat_copy_entries(unsigned char *data, unsigned int size_user, if (ret < 0) return ret; - WARN_ON(size_remaining); + if (size_remaining) + return -EINVAL; + return state->buf_kern_offset; } -- 2.20.1