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authorDan Carpenter <dan.carpenter@oracle.com>2019-04-06 08:26:52 +0300
committerPablo Neira Ayuso <pablo@netfilter.org>2019-04-15 07:31:50 +0200
commit33d1c018179d0a30c39cc5f1682b77867282694b (patch)
tree72c0d98f9a56f6ec1aa8d47d3ca311baa018b4f4 /net/netfilter
parent3c79107631db1f7fd32cf3f7368e4672004a3010 (diff)
downloadlinux-33d1c018179d0a30c39cc5f1682b77867282694b.tar.bz2
netfilter: nf_tables: prevent shift wrap in nft_chain_parse_hook()
I believe that "hook->num" can be up to UINT_MAX. Shifting more than 31 bits would is undefined in C but in practice it would lead to shift wrapping. That would lead to an array overflow in nf_tables_addchain(): ops->hook = hook.type->hooks[ops->hooknum]; Fixes: fe19c04ca137 ("netfilter: nf_tables: remove nhooks field from struct nft_af_info") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
-rw-r--r--net/netfilter/nf_tables_api.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ef7772e976cc..1606eaa5ae0d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1545,7 +1545,7 @@ static int nft_chain_parse_hook(struct net *net,
if (IS_ERR(type))
return PTR_ERR(type);
}
- if (!(type->hook_mask & (1 << hook->num)))
+ if (hook->num > NF_MAX_HOOKS || !(type->hook_mask & (1 << hook->num)))
return -EOPNOTSUPP;
if (type->type == NFT_CHAIN_T_NAT &&