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authorFlorian Westphal <fwestphal@astaro.com>2011-02-17 11:32:38 +0100
committerPatrick McHardy <kaber@trash.net>2011-02-17 11:32:38 +0100
commitd503b30bd648b3cb4e5f50b65d27e389960cc6d9 (patch)
treeebb3e2ad85f32cd95c767dda75d25873c384e78d /net/netfilter/xt_socket.c
parentde9963f0f2dfad128b26ae7bf6005f5948416a6d (diff)
netfilter: tproxy: do not assign timewait sockets to skb->sk
Assigning a socket in timewait state to skb->sk can trigger kernel oops, e.g. in nfnetlink_log, which does: if (skb->sk) { read_lock_bh(&skb->sk->sk_callback_lock); if (skb->sk->sk_socket && skb->sk->sk_socket->file) ... in the timewait case, accessing sk->sk_callback_lock and sk->sk_socket is invalid. Either all of these spots will need to add a test for sk->sk_state != TCP_TIME_WAIT, or xt_TPROXY must not assign a timewait socket to skb->sk. This does the latter. If a TW socket is found, assign the tproxy nfmark, but skip the skb->sk assignment, thus mimicking behaviour of a '-m socket .. -j MARK/ACCEPT' re-routing rule. The 'SYN to TW socket' case is left unchanged -- we try to redirect to the listener socket. Cc: Balazs Scheidler <bazsi@balabit.hu> Cc: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Florian Westphal <fwestphal@astaro.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter/xt_socket.c')
-rw-r--r--net/netfilter/xt_socket.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index 00d6ae838303..9cc46356b577 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -35,6 +35,15 @@
#include <net/netfilter/nf_conntrack.h>
#endif
+static void
+xt_socket_put_sk(struct sock *sk)
+{
+ if (sk->sk_state == TCP_TIME_WAIT)
+ inet_twsk_put(inet_twsk(sk));
+ else
+ sock_put(sk);
+}
+
static int
extract_icmp4_fields(const struct sk_buff *skb,
u8 *protocol,
@@ -164,7 +173,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
(sk->sk_state == TCP_TIME_WAIT &&
inet_twsk(sk)->tw_transparent));
- nf_tproxy_put_sock(sk);
+ xt_socket_put_sk(sk);
if (wildcard || !transparent)
sk = NULL;
@@ -298,7 +307,7 @@ socket_mt6_v1(const struct sk_buff *skb, struct xt_action_param *par)
(sk->sk_state == TCP_TIME_WAIT &&
inet_twsk(sk)->tw_transparent));
- nf_tproxy_put_sock(sk);
+ xt_socket_put_sk(sk);
if (wildcard || !transparent)
sk = NULL;