[PATCH net 4/5] netfilter: xt_recent: fix (increase) ipv6 literal buffer length

From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org,
	pabeni@redhat.com, edumazet@google.com, fw@strlen.de,
	kadlec@netfilter.org
Subject: [PATCH net 4/5] netfilter: xt_recent: fix (increase) ipv6 literal buffer length
Date: Wed,  8 Nov 2023 16:58:01 +0100	[thread overview]
Message-ID: <20231108155802.84617-5-pablo@netfilter.org> (raw)
In-Reply-To: <20231108155802.84617-1-pablo@netfilter.org>

From: Maciej Żenczykowski <zenczykowski@gmail.com>

in6_pton() supports 'low-32-bit dot-decimal representation'
(this is useful with DNS64/NAT64 networks for example):

  # echo +aaaa:bbbb:cccc:dddd:eeee:ffff:1.2.3.4 > /proc/self/net/xt_recent/DEFAULT
  # cat /proc/self/net/xt_recent/DEFAULT
  src=aaaa:bbbb:cccc:dddd:eeee:ffff:0102:0304 ttl: 0 last_seen: 9733848829 oldest_pkt: 1 9733848829

but the provided buffer is too short:

  # echo +aaaa:bbbb:cccc:dddd:eeee:ffff:255.255.255.255 > /proc/self/net/xt_recent/DEFAULT
  -bash: echo: write error: Invalid argument

Fixes: 079aa88fe717 ("netfilter: xt_recent: IPv6 support")
Signed-off-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_recent.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
index 7ddb9a78e3fc..ef93e0d3bee0 100644
--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -561,7 +561,7 @@ recent_mt_proc_write(struct file *file, const char __user *input,
 {
 	struct recent_table *t = pde_data(file_inode(file));
 	struct recent_entry *e;
-	char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
+	char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:255.255.255.255")];
 	const char *c = buf;
 	union nf_inet_addr addr = {};
 	u_int16_t family;
-- 
2.30.2

