| Message ID | 1373364651-10474-2-git-send-email-jasowang@redhat.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Jul 09, 2013 at 06:10:51PM +0800, Jason Wang wrote: > Userspace may produce vectors greater than MAX_SKB_FRAGS. When we try to > linearize parts of the skb to let the rest of iov to be fit in > the frags, we need count copylen into linear when calling macvtap_alloc_skb() > instead of partly counting it into data_len. Since this breaks > zerocopy_sg_from_iovec() since its inner counter assumes nr_frags should > be zero at beginning. This cause nr_frags to be increased wrongly without > setting the correct frags. > > This bug were introduced from b92946e2919134ebe2a4083e4302236295ea2a73 > (macvtap: zerocopy: validate vectors before building skb). > > Cc: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > This patch is needed for stable. > --- > drivers/net/macvtap.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c > index f2c4a3b..b213020 100644 > --- a/drivers/net/macvtap.c > +++ b/drivers/net/macvtap.c > @@ -770,7 +770,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, > copylen = len; > > skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen, > - vnet_hdr.hdr_len, noblock, &err); > + zerocopy ? copylen : vnet_hdr.hdr_len, > + noblock, &err); > if (!skb) > goto err; Same comment as for tun - let's add code for the if statement above. Thanks! > -- > 1.7.1 -- 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
On 07/09/2013 06:35 PM, Michael S. Tsirkin wrote: > On Tue, Jul 09, 2013 at 06:10:51PM +0800, Jason Wang wrote: >> Userspace may produce vectors greater than MAX_SKB_FRAGS. When we try to >> linearize parts of the skb to let the rest of iov to be fit in >> the frags, we need count copylen into linear when calling macvtap_alloc_skb() >> instead of partly counting it into data_len. Since this breaks >> zerocopy_sg_from_iovec() since its inner counter assumes nr_frags should >> be zero at beginning. This cause nr_frags to be increased wrongly without >> setting the correct frags. >> >> This bug were introduced from b92946e2919134ebe2a4083e4302236295ea2a73 >> (macvtap: zerocopy: validate vectors before building skb). >> >> Cc: Michael S. Tsirkin <mst@redhat.com> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> This patch is needed for stable. >> --- >> drivers/net/macvtap.c | 3 ++- >> 1 files changed, 2 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c >> index f2c4a3b..b213020 100644 >> --- a/drivers/net/macvtap.c >> +++ b/drivers/net/macvtap.c >> @@ -770,7 +770,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, >> copylen = len; >> >> skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen, >> - vnet_hdr.hdr_len, noblock, &err); >> + zerocopy ? copylen : vnet_hdr.hdr_len, >> + noblock, &err); >> if (!skb) >> goto err; > Same comment as for tun - let's add code for the if statement above. > Thanks! > Sure, I will post v2. Thanks >> -- >> 1.7.1 > -- > 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 -- 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 f2c4a3b..b213020 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -770,7 +770,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, copylen = len; skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen, - vnet_hdr.hdr_len, noblock, &err); + zerocopy ? copylen : vnet_hdr.hdr_len, + noblock, &err); if (!skb) goto err;
Userspace may produce vectors greater than MAX_SKB_FRAGS. When we try to linearize parts of the skb to let the rest of iov to be fit in the frags, we need count copylen into linear when calling macvtap_alloc_skb() instead of partly counting it into data_len. Since this breaks zerocopy_sg_from_iovec() since its inner counter assumes nr_frags should be zero at beginning. This cause nr_frags to be increased wrongly without setting the correct frags. This bug were introduced from b92946e2919134ebe2a4083e4302236295ea2a73 (macvtap: zerocopy: validate vectors before building skb). Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- This patch is needed for stable. --- drivers/net/macvtap.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)