| Message ID | 20130623142658.GA21141@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 06/23/2013 10:26 PM, Michael S. Tsirkin wrote: > 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> > --- > > Same as the tun patch really. Also stable material. Acked-by: Jason Wang <jasowang@redhat.com> > > drivers/net/macvtap.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c > index 59e9605..4ddd108 100644 > --- a/drivers/net/macvtap.c > +++ b/drivers/net/macvtap.c > @@ -524,8 +524,9 @@ 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; -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Jason Wang <jasowang@redhat.com> Date: Mon, 24 Jun 2013 11:23:15 +0800 > On 06/23/2013 10:26 PM, Michael S. Tsirkin wrote: >> 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> >> --- >> >> Same as the tun patch really. Also stable material. > > Acked-by: Jason Wang <jasowang@redhat.com> Applied, also with the missing empty line added. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 59e9605..4ddd108 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -524,8 +524,9 @@ 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;
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> --- Same as the tun patch really. Also stable material. drivers/net/macvtap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)