1 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index c10e4435e3b1..b018e31b6530 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -435,6 +435,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
         int nsize, old_factor;
         u16 flags;
 
+        BUG_ON(len >= skb->len);
+
         nsize = skb_headlen(skb) - len;
         if (nsize < 0)
                 nsize = 0;