blob: 43df2859bd9579405240d1343a1fc27d2ac2100b [file] [log] [blame]
From 782d1637c80bc5265f4c6f24be64641cffb9107e Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Sat, 18 Jan 2020 11:27:25 +0100
Subject: [PATCH] netfilter: nft_osf: add missing check for DREG attribute
commit 7eaecf7963c1c8f62d62c6a8e7c439b0e7f2d365 upstream.
syzbot reports just another NULL deref crash because of missing test
for presence of the attribute.
Reported-by: syzbot+cf23983d697c26c34f60@syzkaller.appspotmail.com
Fixes: b96af92d6eaf9fadd ("netfilter: nf_tables: implement Passive OS fingerprint module in nft_osf")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c
index f54d6ae15bb1..b42247aa48a9 100644
--- a/net/netfilter/nft_osf.c
+++ b/net/netfilter/nft_osf.c
@@ -61,6 +61,9 @@ static int nft_osf_init(const struct nft_ctx *ctx,
int err;
u8 ttl;
+ if (!tb[NFTA_OSF_DREG])
+ return -EINVAL;
+
if (tb[NFTA_OSF_TTL]) {
ttl = nla_get_u8(tb[NFTA_OSF_TTL]);
if (ttl > 2)
--
2.7.4