3.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jason Wang <jasow...@redhat.com> commit 01d6657b388438def19c8baaea28e742b6ed32ec upstream. Current the SKBTX_DEV_ZEROCOPY is set unconditionally after zerocopy_sg_from_iovec(), this would lead NULL pointer when macvtap fails to build zerocopy skb because destructor_arg was not initialized. Solve this by set this flag after the skb were built successfully. Signed-off-by: Jason Wang <jasow...@redhat.com> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> Cc: Ben Hutchings <b...@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/net/macvtap.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -716,10 +716,9 @@ static ssize_t macvtap_get_user(struct m if (!skb) goto err; - if (zerocopy) { + if (zerocopy) err = zerocopy_sg_from_iovec(skb, iv, vnet_hdr_len, count); - skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; - } else + else err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len, len); if (err) @@ -738,8 +737,10 @@ static ssize_t macvtap_get_user(struct m rcu_read_lock_bh(); vlan = rcu_dereference_bh(q->vlan); /* copy skb_ubuf_info for callback when skb has no error */ - if (zerocopy) + if (zerocopy) { skb_shinfo(skb)->destructor_arg = m->msg_control; + skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + } if (vlan) macvlan_start_xmit(skb, vlan->dev); else -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/