diff options
| author | Florian Westphal <fw@strlen.de> | 2018-09-24 14:10:04 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-09-28 14:47:40 +0200 |
| commit | 421c119f558761556afca6a62ad183bc2d8659e0 (patch) | |
| tree | c18d4d3e8b6eae2c8ee7a78af297c163742d22f6 /include | |
| parent | a13f814a67b12a2f29d1decf4b4f4e700658a517 (diff) | |
netfilter: avoid erronous array bounds warning
Unfortunately some versions of gcc emit following warning:
$ make net/xfrm/xfrm_output.o
linux/compiler.h:252:20: warning: array subscript is above array bounds [-Warray-bounds]
hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
^~~~~~~~~~~~~~~~~~~~~
xfrm_output_resume passes skb_dst(skb)->ops->family as its 'pf' arg so compiler
can't know that we'll never access hooks_arp[].
(NFPROTO_IPV4 or NFPROTO_IPV6 are only possible cases).
Avoid this by adding an explicit WARN_ON_ONCE() check.
This patch has no effect if the family is a compile-time constant as gcc
will remove the switch() construct entirely.
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netfilter.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 07efffd0c759..bbe99d2b28b4 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -215,6 +215,8 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, break; case NFPROTO_ARP: #ifdef CONFIG_NETFILTER_FAMILY_ARP + if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp))) + break; hook_head = rcu_dereference(net->nf.hooks_arp[hook]); #endif break; |