From f4d26fb336f3c08066bffbe907d3104be4fb91a8 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 30 Jul 2006 20:20:28 -0700 Subject: [PATCH] [NET]: Fix ___pskb_trim when entire frag_list needs dropping When the trim point is within the head and there is no paged data, ___pskb_trim fails to drop the first element in the frag_list. This patch fixes this by moving the len <= offset case out of the page data loop. This patch also adds a missing kfree_skb on the frag that we just cloned. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/core/skbuff.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 476aa3978504..d236f02c6467 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -846,7 +846,11 @@ int ___pskb_trim(struct sk_buff *skb, unsigned int len) unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))) return err; - for (i = 0; i < nfrags; i++) { + i = 0; + if (offset >= len) + goto drop_pages; + + for (; i < nfrags; i++) { int end = offset + skb_shinfo(skb)->frags[i].size; if (end < len) { @@ -854,9 +858,9 @@ int ___pskb_trim(struct sk_buff *skb, unsigned int len) continue; } - if (len > offset) - skb_shinfo(skb)->frags[i++].size = len - offset; + skb_shinfo(skb)->frags[i++].size = len - offset; +drop_pages: skb_shinfo(skb)->nr_frags = i; for (; i < nfrags; i++) @@ -864,7 +868,7 @@ int ___pskb_trim(struct sk_buff *skb, unsigned int len) if (skb_shinfo(skb)->frag_list) skb_drop_fraglist(skb); - break; + goto done; } for (fragp = &skb_shinfo(skb)->frag_list; (frag = *fragp); @@ -879,6 +883,7 @@ int ___pskb_trim(struct sk_buff *skb, unsigned int len) return -ENOMEM; nfrag->next = frag->next; + kfree_skb(frag); frag = nfrag; *fragp = frag; } @@ -897,6 +902,7 @@ int ___pskb_trim(struct sk_buff *skb, unsigned int len) break; } +done: if (len > skb_headlen(skb)) { skb->data_len -= skb->len - len; skb->len = len; -- 2.39.2