| | Date | Mon, 23 Jul 2012 02:07:09 +0100 | | From | Ben Hutchings <> | | Subject | [ 018/108] macvtap: zerocopy: put page when fail to get all requested user pages |
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3.2-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jason Wang <jasowang@redhat.com>
commit 02ce04bb3d28c3333231f43bca677228dbc686fe upstream. When get_user_pages_fast() fails to get all requested pages, we could not use kfree_skb() to free it as it has not been put in the skb fragments. So we need to call put_page() instead.
Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/net/macvtap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 7cb2684..9ab182a 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -531,9 +531,11 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT; num_pages = get_user_pages_fast(base, size, 0, &page[i]); if ((num_pages != size) || - (num_pages > MAX_SKB_FRAGS - skb_shinfo(skb)->nr_frags)) - /* put_page is in skb free */ + (num_pages > MAX_SKB_FRAGS - skb_shinfo(skb)->nr_frags)) { + for (i = 0; i < num_pages; i++) + put_page(page[i]); return -EFAULT; + } truesize = size * PAGE_SIZE; skb->data_len += len; skb->len += len;
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