[PATCH net v2 0/2] rtnetlink: add missing attributes in if_nlmsg_size

[PATCH net v2 0/2] rtnetlink: add missing attributes in if_nlmsg_size

[Sabrina Dubroca]

Once again we have some attributes added by rtnl_fill_ifinfo() that
aren't counted in if_nlmsg_size().

v2: add missing nla_total_size in patch 1, spotted by Sergey Ryazanov
    patch 2 unchanged, keep Jiri Pirko's Reviewed-by

Sabrina Dubroca (2):
  rtnetlink: count IFLA_PARENT_DEV_{NAME,BUS_NAME} in if_nlmsg_size
  rtnetlink: count IFLA_INFO_SLAVE_KIND in if_nlmsg_size

 net/core/rtnetlink.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

-- 
2.51.2

[PATCH net v2 1/2] rtnetlink: count IFLA_PARENT_DEV_{NAME,BUS_NAME} in if_nlmsg_size

[Sabrina Dubroca]

Commit 00e77ed8e64d ("rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME")
added those attributes to rtnl_fill_ifinfo, but forgot to extend
if_nlmsg_size.

Fixes: 00e77ed8e64d ("rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
---
 net/core/rtnetlink.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

v2: add nla_total_size, spotted by Sergey Ryazanov
    fix Loic Poulain's email address in the CC list

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index dad4b1054955..0fe279432d82 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1267,6 +1267,21 @@ static size_t rtnl_dpll_pin_size(const struct net_device *dev)
 	return size;
 }
 
+static size_t rtnl_dev_parent_size(const struct net_device *dev)
+{
+	size_t size = 0;
+
+	/* IFLA_PARENT_DEV_NAME */
+	if (dev->dev.parent)
+		size += nla_total_size(strlen(dev_name(dev->dev.parent)) + 1);
+
+	/* IFLA_PARENT_DEV_BUS_NAME */
+	if (dev->dev.parent && dev->dev.parent->bus)
+		size += nla_total_size(strlen(dev->dev.parent->bus->name) + 1);
+
+	return size;
+}
+
 static noinline size_t if_nlmsg_size(const struct net_device *dev,
 				     u32 ext_filter_mask)
 {
@@ -1328,6 +1343,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + nla_total_size(8)  /* IFLA_MAX_PACING_OFFLOAD_HORIZON */
 	       + nla_total_size(2)  /* IFLA_HEADROOM */
 	       + nla_total_size(2)  /* IFLA_TAILROOM */
+	       + rtnl_dev_parent_size(dev)
 	       + 0;
 
 	if (!(ext_filter_mask & RTEXT_FILTER_SKIP_STATS))
-- 
2.51.2

Re: [PATCH net v2 1/2] rtnetlink: count IFLA_PARENT_DEV_{NAME,BUS_NAME} in if_nlmsg_size

[Sergey Ryazanov]

On 3/20/26 01:02, Sabrina Dubroca wrote:
> Commit 00e77ed8e64d ("rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME")
> added those attributes to rtnl_fill_ifinfo, but forgot to extend
> if_nlmsg_size.
> 
> Fixes: 00e77ed8e64d ("rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME")
> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>

Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>

[PATCH net v2 2/2] rtnetlink: count IFLA_INFO_SLAVE_KIND in if_nlmsg_size

[Sabrina Dubroca]

rtnl_link_get_slave_info_data_size counts IFLA_INFO_SLAVE_DATA, but
rtnl_link_slave_info_fill adds both IFLA_INFO_SLAVE_DATA and
IFLA_INFO_SLAVE_KIND.

Fixes: ba7d49b1f0f8 ("rtnetlink: provide api for getting and setting slave info")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
---
 net/core/rtnetlink.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

v2: unchanged, keep Reviewed-by from v1

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 0fe279432d82..4a2278614250 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -707,11 +707,14 @@ static size_t rtnl_link_get_slave_info_data_size(const struct net_device *dev)
 		goto out;
 
 	ops = master_dev->rtnl_link_ops;
-	if (!ops || !ops->get_slave_size)
+	if (!ops)
+		goto out;
+	size += nla_total_size(strlen(ops->kind) + 1);  /* IFLA_INFO_SLAVE_KIND */
+	if (!ops->get_slave_size)
 		goto out;
 	/* IFLA_INFO_SLAVE_DATA + nested data */
-	size = nla_total_size(sizeof(struct nlattr)) +
-	       ops->get_slave_size(master_dev, dev);
+	size += nla_total_size(sizeof(struct nlattr)) +
+		ops->get_slave_size(master_dev, dev);
 
 out:
 	rcu_read_unlock();
-- 
2.51.2

Re: [PATCH net v2 0/2] rtnetlink: add missing attributes in if_nlmsg_size

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 20 Mar 2026 00:02:51 +0100 you wrote:
> Once again we have some attributes added by rtnl_fill_ifinfo() that
> aren't counted in if_nlmsg_size().
> 
> v2: add missing nla_total_size in patch 1, spotted by Sergey Ryazanov
>     patch 2 unchanged, keep Jiri Pirko's Reviewed-by
> 
> Sabrina Dubroca (2):
>   rtnetlink: count IFLA_PARENT_DEV_{NAME,BUS_NAME} in if_nlmsg_size
>   rtnetlink: count IFLA_INFO_SLAVE_KIND in if_nlmsg_size
> 
> [...]

Here is the summary with links:
  - [net,v2,1/2] rtnetlink: count IFLA_PARENT_DEV_{NAME,BUS_NAME} in if_nlmsg_size
    https://git.kernel.org/netdev/net/c/52501989c762
  - [net,v2,2/2] rtnetlink: count IFLA_INFO_SLAVE_KIND in if_nlmsg_size
    https://git.kernel.org/netdev/net/c/ee00a12593ff

You are awesome, thank you!
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