[PATCH 4.14 42/61] netfilter: nf_tables: use WARN_ON_ONCE instead of BUG_ON in nft_do_chain()

From: Greg Kroah-Hartman
Date: Fri Jul 06 2018 - 01:57:11 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Taehee Yoo <ap420073@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx>
Acked-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/netfilter/nf_tables_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- 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;