From: Eric Dumazet <edumazet@xxxxxxxxxx>
commit 681f130f39e10 ("netfilter: xt_socket: add XT_SOCKET_NOWILDCARD
flag") added a potential NULL dereference if an old iptables package
uses v0 of the match.
Fix this by removing the test on @info in fast path.
IPv6 can remove the test as well, as it uses v1 or v2.
Reported-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Patrick McHardy <kaber@xxxxxxxxx>
---
net/netfilter/xt_socket.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index f8b7191..20b1591 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -172,7 +172,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
/* Ignore non-transparent sockets,
if XT_SOCKET_TRANSPARENT is used */
- if (info && info->flags & XT_SOCKET_TRANSPARENT)
+ if (info->flags & XT_SOCKET_TRANSPARENT)
transparent = ((sk->sk_state != TCP_TIME_WAIT &&
inet_sk(sk)->transparent) ||
(sk->sk_state == TCP_TIME_WAIT &&
@@ -196,7 +196,11 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
static bool
socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par)
{
- return socket_match(skb, par, NULL);
+ static struct xt_socket_mtinfo1 xt_info_v0 = {
+ .flags = 0,
+ };
+
+ return socket_match(skb, par, &xt_info_v0);
}
static bool
@@ -314,7 +318,7 @@ socket_mt6_v1_v2(const struct sk_buff *skb, struct xt_action_param *par)
/* Ignore non-transparent sockets,
if XT_SOCKET_TRANSPARENT is used */
- if (info && info->flags & XT_SOCKET_TRANSPARENT)
+ if (info->flags & XT_SOCKET_TRANSPARENT)
transparent = ((sk->sk_state != TCP_TIME_WAIT &&
inet_sk(sk)->transparent) ||
(sk->sk_state == TCP_TIME_WAIT &&
--
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