path: root/drivers
diff options
authorMichael S. Tsirkin <mst@redhat.com>2013-06-23 17:19:03 +0300
committerDavid S. Miller <davem@davemloft.net>2013-06-25 16:16:45 -0700
commit7e24bfbe43b545b1689a5f134ed83645b9e34b86 (patch)
tree74dde1d00b2eb4c739dbe1375853e0e7383ac523 /drivers
parentbd8a7036c06cf15779b31a5397d4afcb12be81ea (diff)
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: Brad Hubbard <bhubbard@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index bfa9bb48e42..9c61f8734a4 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -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;