net_sched: fix mirrored packets checksum

Similar to commit 9b368814b336 ("net: fix bridge multicast packet checksum validation")
we need to fixup the checksum for CHECKSUM_COMPLETE when
pushing skb on RX path. Otherwise we get similar splats.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 20 insertions, 19 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 24859d40acde..f39b37180c41 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2871,6 +2871,25 @@ static inline void skb_postpush_rcsum(struct sk_buff *skb,
 }
 
 /**
+ *      skb_push_rcsum - push skb and update receive checksum
+ *      @skb: buffer to update
+ *      @len: length of data pulled
+ *
+ *      This function performs an skb_push on the packet and updates
+ *      the CHECKSUM_COMPLETE checksum.  It should be used on
+ *      receive path processing instead of skb_push unless you know
+ *      that the checksum difference is zero (e.g., a valid IP header)
+ *      or you are setting ip_summed to CHECKSUM_NONE.
+ */
+static inline unsigned char *skb_push_rcsum(struct sk_buff *skb,
+                                            unsigned int len)
+{
+        skb_push(skb, len);
+        skb_postpush_rcsum(skb, skb->data, len);
+        return skb->data;
+}
+
+/**
  *      pskb_trim_rcsum - trim received skb and update checksum
  *      @skb: buffer to trim
  *      @len: new length
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f2b77e549c03..eb12d2161fb2 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3016,24 +3016,6 @@ int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
 EXPORT_SYMBOL_GPL(skb_append_pagefrags);
 
 /**
- *      skb_push_rcsum - push skb and update receive checksum
- *      @skb: buffer to update
- *      @len: length of data pulled
- *
- *      This function performs an skb_push on the packet and updates
- *      the CHECKSUM_COMPLETE checksum.  It should be used on
- *      receive path processing instead of skb_push unless you know
- *      that the checksum difference is zero (e.g., a valid IP header)
- *      or you are setting ip_summed to CHECKSUM_NONE.
- */
-static unsigned char *skb_push_rcsum(struct sk_buff *skb, unsigned len)
-{
-        skb_push(skb, len);
-        skb_postpush_rcsum(skb, skb->data, len);
-        return skb->data;
-}
-
-/**
  *      skb_pull_rcsum - pull skb and update receive checksum
  *      @skb: buffer to update
  *      @len: length of data pulled
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 128942bc9e42..1f5bd6ccbd2c 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -181,7 +181,7 @@ static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
 
         if (!(at & AT_EGRESS)) {
                 if (m->tcfm_ok_push)
-                        skb_push(skb2, skb->mac_len);
+                        skb_push_rcsum(skb2, skb->mac_len);
         }
 
         /* mirror is always swallowed */