3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Michael S. Tsirkin" <mst@xxxxxxxxxx> [ Upstream commit 4c7ab054ab4f5d63625508ed6f8a607184cae7c2 ] get user pages might fail partially in macvtap zero copy mode. To recover we need to put all pages that we got, but code used a wrong index resulting in double-free errors. Reported-by: Brad Hubbard <bhubbard@xxxxxxxxxx> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/macvtap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -534,8 +534,10 @@ static int zerocopy_sg_from_iovec(struct return -EMSGSIZE; num_pages = get_user_pages_fast(base, size, 0, &page[i]); if (num_pages != size) { - for (i = 0; i < num_pages; i++) - put_page(page[i]); + int j; + + for (j = 0; j < num_pages; j++) + put_page(page[i + j]); } truesize = size * PAGE_SIZE; skb->data_len += len; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html