Commit 5b5a60da authored Jun 23, 2007 by Olaf Kirch Committed by David S. Miller Jun 23, 2007

[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>

parent 515e06c4

net/core/skbuff.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1706,6 +1706,11 @@ unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
		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;