From: Taehee Yoo <ap420073@gmail.com>
Date: Mon, 11 Jun 2018 13:16:33 +0000 (+0900)
Subject: netfilter: nf_tables: use WARN_ON_ONCE instead of BUG_ON in nft_do_chain()
X-Git-Tag: v4.17.5~4
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=012007a1dd19a437583a7b45018aaef14642093c;p=linux

netfilter: nf_tables: use WARN_ON_ONCE instead of BUG_ON in nft_do_chain()

commit adc972c5b88829d38ede08b1069718661c7330ae upstream.

When depth of chain is bigger than NFT_JUMP_STACK_SIZE, the nft_do_chain
crashes. But there is no need to crash hard here.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index 40e744572283..32b7896929f3 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -208,7 +208,8 @@ next_rule:
 
 	switch (regs.verdict.code) {
 	case NFT_JUMP:
-		BUG_ON(stackptr >= NFT_JUMP_STACK_SIZE);
+		if (WARN_ON_ONCE(stackptr >= NFT_JUMP_STACK_SIZE))
+			return NF_DROP;
 		jumpstack[stackptr].chain = chain;
 		jumpstack[stackptr].rule  = rule;
 		jumpstack[stackptr].rulenum = rulenum;