[NET]: Make skb_seq_read unmap the last fragment

Having walked through the entire skbuff, skb_seq_read would leave the
last fragment mapped.  As a consequence, the unwary caller would leak
kmaps, and proceed with preempt_count off by one. The only (kind of
non-intuitive) workaround is to use skb_seq_read_abort.

This patch makes sure skb_seq_read always unmaps frag_data after
having cycled through the skb's paged part.

Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Olaf Kirch 2007-06-23 23:11:52 -07:00 коммит произвёл David S. Miller
Родитель 515e06c455
Коммит 5b5a60da28
1 изменённых файлов: 5 добавлений и 0 удалений

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@ -1706,6 +1706,11 @@ next_skb:
st->stepped_offset += frag->size;
}
if (st->frag_data) {
kunmap_skb_frag(st->frag_data);
st->frag_data = NULL;
}
if (st->cur_skb->next) {
st->cur_skb = st->cur_skb->next;
st->frag_idx = 0;