Commit 7e24bfbe authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by David S. Miller

tun: fix recovery from gup errors

get user pages might fail partially in tun 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: default avatarBrad Hubbard <bhubbard@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bd8a7036
......@@ -1010,8 +1010,10 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
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]);
return -EFAULT;
}
truesize = size * PAGE_SIZE;
......
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