3 files changed, 18 insertions, 3 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3573ba9a2555..755e9cddac47 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1040,6 +1040,21 @@ static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
 }
 
 /**
+ *      pskb_trim_unique - remove end from a paged unique (not cloned) buffer
+ *      @skb: buffer to alter
+ *      @len: new length
+ *
+ *      This is identical to pskb_trim except that the caller knows that
+ *      the skb is not cloned so we should never get an error due to out-
+ *      of-memory.
+ */
+static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
+{
+        int err = pskb_trim(skb, len);
+        BUG_ON(err);
+}
+
+/**
  *      skb_orphan - orphan a buffer
  *      @skb: buffer to orphan
  *
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 9bf307a29783..4c20f5546893 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -947,7 +947,7 @@ alloc_new_skb:
                                 skb_prev->csum = csum_sub(skb_prev->csum,
                                                           skb->csum);
                                 data += fraggap;
-                                skb_trim(skb_prev, maxfraglen);
+                                pskb_trim_unique(skb_prev, maxfraglen);
                         }
 
                         copy = datalen - transhdrlen - fraggap;
@@ -1142,7 +1142,7 @@ ssize_t	ip_append_page(struct sock *sk, struct page *page,
                                         data, fraggap, 0);
                                 skb_prev->csum = csum_sub(skb_prev->csum,
                                                           skb->csum);
-                                skb_trim(skb_prev, maxfraglen);
+                                pskb_trim_unique(skb_prev, maxfraglen);
                         }
 
                         /*
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 69451af6abe7..4fb47a252913 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1095,7 +1095,7 @@ alloc_new_skb:
                                 skb_prev->csum = csum_sub(skb_prev->csum,
                                                           skb->csum);
                                 data += fraggap;
-                                skb_trim(skb_prev, maxfraglen);
+                                pskb_trim_unique(skb_prev, maxfraglen);
                         }
                         copy = datalen - transhdrlen - fraggap;
                         if (copy < 0) {