From: Chuck Lever Date: Sun, 11 Nov 2007 05:53:30 +0000 (-0800) Subject: [NET]: Fix skb_truesize_check() assertion X-Git-Tag: v2.6.24-rc3~155^2~24 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=78608ba0326f1448f9a10dbb402a38192559f639;p=linux-2.6 [NET]: Fix skb_truesize_check() assertion The intent of the assertion in skb_truesize_check() is to check for skb->truesize being decremented too much by other code, resulting in a wraparound below zero. The type of the right side of the comparison causes the compiler to promote the left side to an unsigned type, despite the presence of an explicit type cast. This defeats the check for negativity. Ensure both sides of the comparison are a signed type to prevent the implicit type conversion. Signed-off-by: Chuck Lever Signed-off-by: David S. Miller --- diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 94e49915a8..91140fe8c1 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -387,7 +387,9 @@ extern void skb_truesize_bug(struct sk_buff *skb); static inline void skb_truesize_check(struct sk_buff *skb) { - if (unlikely((int)skb->truesize < sizeof(struct sk_buff) + skb->len)) + int len = sizeof(struct sk_buff) + skb->len; + + if (unlikely((int)skb->truesize < len)) skb_truesize_bug(skb); }