[patch 32/47] net: Fix frag_list handling in skb_seq_read

Greg KH
2009-02-14T01:13:33Z

[-- Attachment #1: net-fix-frag_list-handling-in-skb_seq_read.patch --]
[-- Type: text/plain, Size: 1417 bytes --]

2.6.27-stable review patch. If anyone has any objections, please let us know.

------------------

From: Herbert Xu <herbert@gondor.apana.org.au>

[ Upstream commit 95e3b24cfb4ec0479d2c42f7a1780d68063a542a ]

The frag_list handling was broken in skb_seq_read:

1) We didn't add the stepped offset when looking at the head
are of fragments other than the first.

2) We didn't take the stepped offset away when setting the data
pointer in the head area.

3) The frag index wasn't reset.

This patch fixes both issues.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
net/core/skbuff.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2001,10 +2001,10 @@ unsigned int skb_seq_read(unsigned int c
return 0;

next_skb:
- block_limit = skb_headlen(st->cur_skb);
+ block_limit = skb_headlen(st->cur_skb) + st->stepped_offset;

if (abs_offset < block_limit) {
- *data = st->cur_skb->data + abs_offset;
+ *data = st->cur_skb->data + (abs_offset - st->stepped_offset);
return block_limit - abs_offset;
}

@@ -2046,6 +2046,7 @@ next_skb:
} else if (st->root_skb == st->cur_skb &&
skb_shinfo(st->root_skb)->frag_list) {
st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
+ st->frag_idx = 0;
goto next_skb;
}