[PATCH 6.18 095/309] rtnetlink: count IFLA_PARENT_DEV_{NAME,BUS_NAME} in if_nlmsg_size

Greg Kroah-Hartman
2026-03-31T17:01:56Z

From: Sabrina Dubroca <sd@queasysnail.net>

[ Upstream commit 52501989c76206462d9b11a8485beef40ef41821 ]

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>
Link: https://patch.msgid.link/0b849da95562af45487080528d60f578636aba5c.1773919462.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/rtnetlink.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 576d5ec3bb364..1960b59961cb8 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;
}

--
2.51.0