[PATCH net] rtnetlink: fix rtnl_vfinfo_size

[PATCH net] rtnetlink: fix rtnl_vfinfo_size

[Sabrina Dubroca]

The size reported by rtnl_vfinfo_size doesn't match the space used by
rtnl_fill_vfinfo.

rtnl_vfinfo_size currently doesn't account for the nest attributes
used by statistics (added in commit 3b766cd83232), nor for struct
ifla_vf_tx_rate (since commit ed616689a3d9, which added ifla_vf_rate
to the dump without removing ifla_vf_tx_rate, but replaced
ifla_vf_tx_rate with ifla_vf_rate in the size computation).

Fixes: 3b766cd83232 ("net/core: Add reading VF statistics through the PF netdevice")
Fixes: ed616689a3d9 ("net-next:v4: Add support to configure SR-IOV VF minimum and maximum Tx rate through ip tool")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
---
 net/core/rtnetlink.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index db313ec7af32..96f4bf274e30 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -840,18 +840,20 @@ static inline int rtnl_vfinfo_size(const struct net_device *dev,
 	if (dev->dev.parent && dev_is_pci(dev->dev.parent) &&
 	    (ext_filter_mask & RTEXT_FILTER_VF)) {
 		int num_vfs = dev_num_vf(dev->dev.parent);
-		size_t size = nla_total_size(sizeof(struct nlattr));
-		size += nla_total_size(num_vfs * sizeof(struct nlattr));
+		size_t size = nla_total_size(0);
 		size += num_vfs *
-			(nla_total_size(sizeof(struct ifla_vf_mac)) +
-			 nla_total_size(MAX_VLAN_LIST_LEN *
-					sizeof(struct nlattr)) +
+			(nla_total_size(0) +
+			 nla_total_size(sizeof(struct ifla_vf_mac)) +
+			 nla_total_size(sizeof(struct ifla_vf_vlan)) +
+			 nla_total_size(0) + /* nest IFLA_VF_VLAN_LIST */
 			 nla_total_size(MAX_VLAN_LIST_LEN *
 					sizeof(struct ifla_vf_vlan_info)) +
 			 nla_total_size(sizeof(struct ifla_vf_spoofchk)) +
+			 nla_total_size(sizeof(struct ifla_vf_tx_rate)) +
 			 nla_total_size(sizeof(struct ifla_vf_rate)) +
 			 nla_total_size(sizeof(struct ifla_vf_link_state)) +
 			 nla_total_size(sizeof(struct ifla_vf_rss_query_en)) +
+			 nla_total_size(0) + /* nest IFLA_VF_STATS */
 			 /* IFLA_VF_STATS_RX_PACKETS */
 			 nla_total_size_64bit(sizeof(__u64)) +
 			 /* IFLA_VF_STATS_TX_PACKETS */
-- 
2.10.2

Re: [PATCH net] rtnetlink: fix rtnl_vfinfo_size

[David Miller]

From: Sabrina Dubroca <sd@queasysnail.net>
Date: Tue, 15 Nov 2016 10:39:03 +0100

> The size reported by rtnl_vfinfo_size doesn't match the space used by
> rtnl_fill_vfinfo.
> 
> rtnl_vfinfo_size currently doesn't account for the nest attributes
> used by statistics (added in commit 3b766cd83232), nor for struct
> ifla_vf_tx_rate (since commit ed616689a3d9, which added ifla_vf_rate
> to the dump without removing ifla_vf_tx_rate, but replaced
> ifla_vf_tx_rate with ifla_vf_rate in the size computation).
> 
> Fixes: 3b766cd83232 ("net/core: Add reading VF statistics through the PF netdevice")
> Fixes: ed616689a3d9 ("net-next:v4: Add support to configure SR-IOV VF minimum and maximum Tx rate through ip tool")
> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>

Applied and queued up for -stable.