Re: [PATCH] macvtap: fix the uninitialized var using inmacvtap_alloc_skb()

From: Michael S. Tsirkin
Date: Mon Sep 19 2011 - 05:53:13 EST


On Mon, Sep 19, 2011 at 05:48:31PM +0800, Jason Wang wrote:
> Commit d1b08284 use new frag API but would leave f to be used
> uninitialized, this patch fix it.
>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>

Good catch. Makes absolute sense.

Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>

> ---
> drivers/net/macvtap.c | 12 +++++-------
> 1 files changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
> index 7c3f84a..3da5578 100644
> --- a/drivers/net/macvtap.c
> +++ b/drivers/net/macvtap.c
> @@ -453,7 +453,6 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
> int copy = skb_headlen(skb);
> int size, offset1 = 0;
> int i = 0;
> - skb_frag_t *f;
>
> /* Skip over from offset */
> while (count && (offset >= from->iov_len)) {
> @@ -503,14 +502,13 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
> skb->truesize += len;
> atomic_add(len, &skb->sk->sk_wmem_alloc);
> while (len) {
> - __skb_fill_page_desc(
> - skb, i, page[i],
> - base & ~PAGE_MASK,
> - min_t(int, len, PAGE_SIZE - f->page_offset));
> + int off = base & ~PAGE_MASK;
> + int size = min_t(int, len, PAGE_SIZE - off);
> + __skb_fill_page_desc(skb, i, page[i], off, size);
> skb_shinfo(skb)->nr_frags++;
> /* increase sk_wmem_alloc */
> - base += f->size;
> - len -= f->size;
> + base += size;
> + len -= size;
> i++;
> }
> offset1 = 0;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/