Message ID | 1405624192-21722-3-git-send-email-zoltan.kiss@citrix.com |
---|---|
State | Superseded, archived |
Delegated to: | David Miller |
Headers | show |
On Thu, Jul 17, 2014 at 08:09:50PM +0100, Zoltan Kiss wrote: > When the grant operations failed, the skb is freed up eventually, and it tries > to release the frags, if there is any. For the main skb nr_frags is set to 0 to > avoid this, but on the frag_list it iterates through the frags array, and tries > to call put_page on the page pointer which contains garbage at that time. > > Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> > Reported-by: Armin Zentai <armin.zentai@ezit.hu> > Cc: netdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: xen-devel@lists.xenproject.org > --- > diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c > index 604ff71..e9ffb05 100644 > --- a/drivers/net/xen-netback/netback.c > +++ b/drivers/net/xen-netback/netback.c > @@ -1522,6 +1522,11 @@ static int xenvif_tx_submit(struct xenvif_queue *queue) > /* Check the remap error code. */ > if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) { It's worth adding a comment here saying that all those pages have been freed in xenvif_tx_check_gop so that we don't leak any page even if we manually set nr_frags to 0. Wei. > skb_shinfo(skb)->nr_frags = 0; > + if (skb_has_frag_list(skb)) { > + struct sk_buff *nskb = > + skb_shinfo(skb)->frag_list; > + skb_shinfo(nskb)->nr_frags = 0; > + } > kfree_skb(skb); > continue; > } -- 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/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 604ff71..e9ffb05 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1522,6 +1522,11 @@ static int xenvif_tx_submit(struct xenvif_queue *queue) /* Check the remap error code. */ if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) { skb_shinfo(skb)->nr_frags = 0; + if (skb_has_frag_list(skb)) { + struct sk_buff *nskb = + skb_shinfo(skb)->frag_list; + skb_shinfo(nskb)->nr_frags = 0; + } kfree_skb(skb); continue; }
When the grant operations failed, the skb is freed up eventually, and it tries to release the frags, if there is any. For the main skb nr_frags is set to 0 to avoid this, but on the frag_list it iterates through the frags array, and tries to call put_page on the page pointer which contains garbage at that time. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Reported-by: Armin Zentai <armin.zentai@ezit.hu> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xenproject.org --- -- 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