net: protect NAPI config fields with netdev_lock()

Protect the following members of netdev and napi by netdev_lock:
 - defer_hard_irqs,
 - gro_flush_timeout,
 - irq_suspend_timeout.

The first two are written via sysfs (which this patch switches
to new lock), and netdev genl which holds both netdev and rtnl locks.

irq_suspend_timeout is only written by netdev genl.

Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115035319.559603-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 9365a7185a1d..07cb99b114bd 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -450,7 +450,7 @@ static ssize_t gro_flush_timeout_store(struct device *dev,
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
-	return netdev_store(dev, attr, buf, len, change_gro_flush_timeout);
+	return netdev_lock_store(dev, attr, buf, len, change_gro_flush_timeout);
 }
 NETDEVICE_SHOW_RW(gro_flush_timeout, fmt_ulong);
 
@@ -470,7 +470,8 @@ static ssize_t napi_defer_hard_irqs_store(struct device *dev,
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
-	return netdev_store(dev, attr, buf, len, change_napi_defer_hard_irqs);
+	return netdev_lock_store(dev, attr, buf, len,
+				 change_napi_defer_hard_irqs);
 }
 NETDEVICE_SHOW_RW(napi_defer_hard_irqs, fmt_uint);