From: Dan Carpenter <dan.carpenter@oracle.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>,
Florian Westphal <fw@strlen.de>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
netdev@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH net-next] netfilter: nfnetlink_hook: fix check for snprintf() overflow
Date: Sat, 19 Jun 2021 16:55:46 +0300 [thread overview]
Message-ID: <YM33YmacZTH820Cv@mwanda> (raw)
The kernel version of snprintf() can't return negatives. The
"ret > (int)sizeof(sym)" check is off by one because and it should be
>=. Finally, we need to set a negative error code.
Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
net/netfilter/nfnetlink_hook.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nfnetlink_hook.c b/net/netfilter/nfnetlink_hook.c
index 58fda6ac663b..50b4e3c9347a 100644
--- a/net/netfilter/nfnetlink_hook.c
+++ b/net/netfilter/nfnetlink_hook.c
@@ -126,8 +126,10 @@ static int nfnl_hook_dump_one(struct sk_buff *nlskb,
#ifdef CONFIG_KALLSYMS
ret = snprintf(sym, sizeof(sym), "%ps", ops->hook);
- if (ret < 0 || ret > (int)sizeof(sym))
+ if (ret >= sizeof(sym)) {
+ ret = -EINVAL;
goto nla_put_failure;
+ }
module_name = strstr(sym, " [");
if (module_name) {
--
2.30.2
next reply other threads:[~2021-06-19 13:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-19 13:55 Dan Carpenter [this message]
2021-06-20 20:45 ` [PATCH net-next] netfilter: nfnetlink_hook: fix check for snprintf() overflow Florian Westphal
2021-06-21 20:06 ` Pablo Neira Ayuso
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