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authorMichael S. Tsirkin <mst@redhat.com>2013-06-23 17:26:58 +0300
committerDavid S. Miller <davem@davemloft.net>2013-06-25 16:17:10 -0700
commit4c7ab054ab4f5d63625508ed6f8a607184cae7c2 (patch)
tree63273346588712553b8bece014b124cd2b6196e4
parent7e24bfbe43b545b1689a5f134ed83645b9e34b86 (diff)
downloadlinux-linaro-stable-4c7ab054ab4f5d63625508ed6f8a607184cae7c2.tar.gz
macvtap: fix recovery from gup errors
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@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/macvtap.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 59e9605de316..b6dd6a75919a 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -524,8 +524,10 @@ 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;