netfilter: don't reset nf_trace in nf_reset()

[ Upstream commit 124dff01afbdbff251f0385beca84ba1b9adda68 ]

Commit 130549fe ("netfilter: reset nf_trace in nf_reset") added code
to reset nf_trace in nf_reset(). This is wrong and unnecessary.

nf_reset() is used in the following cases:

- when passing packets up the the socket layer, at which point we want to
  release all netfilter references that might keep modules pinned while
  the packet is queued. nf_trace doesn't matter anymore at this point.

- when encapsulating or decapsulating IPsec packets. We want to continue
  tracing these packets after IPsec processing.

- when passing packets through virtual network devices. Only devices on
  that encapsulate in IPv4/v6 matter since otherwise nf_trace is not
  used anymore. Its not entirely clear whether those packets should
  be traced after that, however we've always done that.

- when passing packets through virtual network devices that make the
  packet cross network namespace boundaries. This is the only cases
  where we clearly want to reset nf_trace and is also what the
  original patch intended to fix.

Add a new function nf_reset_trace() and use it in dev_forward_skb() to
fix this properly.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 4aea870cc1ada0f3282526055ee278cad2d05611..dc4d49a0c07dd8772b64dffe3132aece431fa8b5 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2392,6 +2392,13 @@ static inline void nf_reset(struct sk_buff *skb)
 #endif
 }
 
+static inline void nf_reset_trace(struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
+       skb->nf_trace = 0;
+#endif
+}
+
 /* Note: This doesn't put any conntrack and bridge info in dst. */
 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
 {

diff --git a/net/core/dev.c b/net/core/dev.c
index 9e2e29bee65d930623d2d48adb86300c1e457cdb..a8cffb43e90c1b711c6c08148189be27e0987903 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1628,6 +1628,7 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
        skb->mark = 0;
        secpath_reset(skb);
        nf_reset(skb);
+       nf_reset_trace(skb);
        return netif_rx(skb);
 }
 EXPORT_SYMBOL_GPL(dev_forward_skb);