diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2006-06-09 16:13:38 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-06-17 21:30:22 -0700 |
| commit | 3cc0e873986fe594d0e96d07259b11f755325cb2 (patch) | |
| tree | 5d3e9a57333a2d7088a6a63c09bc97db98f480af | |
| parent | b38dfee3d616ffadb58d4215e3ff9d1d7921031e (diff) | |
[NET]: Warn in __skb_trim if skb is paged
It's better to warn and fail rather than rarely triggering BUG on paths
that incorrectly call skb_trim/__skb_trim on a non-linear skb.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/skbuff.h | 24 | ||||
| -rw-r--r-- | net/core/skbuff.c | 7 |
2 files changed, 14 insertions, 17 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 830f58fa03a2..93e4db221585 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -975,15 +975,16 @@ static inline void skb_reserve(struct sk_buff *skb, int len) #define NET_SKB_PAD 16 #endif -extern int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc); +extern int ___pskb_trim(struct sk_buff *skb, unsigned int len); static inline void __skb_trim(struct sk_buff *skb, unsigned int len) { - if (!skb->data_len) { - skb->len = len; - skb->tail = skb->data + len; - } else - ___pskb_trim(skb, len, 0); + if (unlikely(skb->data_len)) { + WARN_ON(1); + return; + } + skb->len = len; + skb->tail = skb->data + len; } /** @@ -993,6 +994,7 @@ static inline void __skb_trim(struct sk_buff *skb, unsigned int len) * * Cut the length of a buffer down by removing data from the tail. If * the buffer is already under the length specified it is not modified. + * The skb must be linear. */ static inline void skb_trim(struct sk_buff *skb, unsigned int len) { @@ -1003,12 +1005,10 @@ static inline void skb_trim(struct sk_buff *skb, unsigned int len) static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) { - if (!skb->data_len) { - skb->len = len; - skb->tail = skb->data+len; - return 0; - } - return ___pskb_trim(skb, len, 1); + if (skb->data_len) + return ___pskb_trim(skb, len); + __skb_trim(skb, len); + return 0; } static inline int pskb_trim(struct sk_buff *skb, unsigned int len) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 96cdcbe24ba2..bb7210f4005e 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -801,12 +801,10 @@ struct sk_buff *skb_pad(struct sk_buff *skb, int pad) return nskb; } -/* Trims skb to length len. It can change skb pointers, if "realloc" is 1. - * If realloc==0 and trimming is impossible without change of data, - * it is BUG(). +/* Trims skb to length len. It can change skb pointers. */ -int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc) +int ___pskb_trim(struct sk_buff *skb, unsigned int len) { int offset = skb_headlen(skb); int nfrags = skb_shinfo(skb)->nr_frags; @@ -816,7 +814,6 @@ int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc) int end = offset + skb_shinfo(skb)->frags[i].size; if (end > len) { if (skb_cloned(skb)) { - BUG_ON(!realloc); if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) return -ENOMEM; } |