[PATCH net-next v2] net: bridge: replace simple_strtoul with kstrtoul

[PATCH net-next v2] net: bridge: replace simple_strtoul with kstrtoul

[Aadarsh Chandra]

The simple_strtoul() function is deprecated. It does not handle
errors or overflows correctly. Replace it with kstrtoul() in
brport_store() to ensure that invalid user input is caught and
returned as an error.

v2: target net-next and simplify by reusing the ret variable as
    suggested by Nikolay Aleksandrov.

Signed-off-by: Aadarsh Chandra <aadarsh.official.xz@gmail.com>
---
 net/bridge/br_sysfs_if.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index 1f57c36a7fc0..cdecc7d1260c 100644
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c
@@ -318,7 +318,6 @@ static ssize_t brport_store(struct kobject *kobj,
 	struct net_bridge_port *p = kobj_to_brport(kobj);
 	ssize_t ret = -EINVAL;
 	unsigned long val;
-	char *endp;
 
 	if (!ns_capable(dev_net(p->dev)->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
@@ -339,8 +338,8 @@ static ssize_t brport_store(struct kobject *kobj,
 		spin_unlock_bh(&p->br->lock);
 		kfree(buf_copy);
 	} else if (brport_attr->store) {
-		val = simple_strtoul(buf, &endp, 0);
-		if (endp == buf)
+		ret = kstrtoul(buf, 0, &val);
+		if (ret)
 			goto out_unlock;
 		spin_lock_bh(&p->br->lock);
 		ret = brport_attr->store(p, val);
-- 
2.54.0

Re: [PATCH net-next v2] net: bridge: replace simple_strtoul with kstrtoul

[Nikolay Aleksandrov]

On 05/05/2026 10:45, Aadarsh Chandra wrote:
> The simple_strtoul() function is deprecated. It does not handle
> errors or overflows correctly. Replace it with kstrtoul() in
> brport_store() to ensure that invalid user input is caught and
> returned as an error.
> 
> v2: target net-next and simplify by reusing the ret variable as
>      suggested by Nikolay Aleksandrov.
> 

Nice that you've given us the changes, but it should be below...


> Signed-off-by: Aadarsh Chandra <aadarsh.official.xz@gmail.com>
> ---

... here, so it's not included in the commit message.

>   net/bridge/br_sysfs_if.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
> index 1f57c36a7fc0..cdecc7d1260c 100644
> --- a/net/bridge/br_sysfs_if.c
> +++ b/net/bridge/br_sysfs_if.c
> @@ -318,7 +318,6 @@ static ssize_t brport_store(struct kobject *kobj,
>   	struct net_bridge_port *p = kobj_to_brport(kobj);
>   	ssize_t ret = -EINVAL;
>   	unsigned long val;
> -	char *endp;
>   
>   	if (!ns_capable(dev_net(p->dev)->user_ns, CAP_NET_ADMIN))
>   		return -EPERM;
> @@ -339,8 +338,8 @@ static ssize_t brport_store(struct kobject *kobj,
>   		spin_unlock_bh(&p->br->lock);
>   		kfree(buf_copy);
>   	} else if (brport_attr->store) {
> -		val = simple_strtoul(buf, &endp, 0);
> -		if (endp == buf)
> +		ret = kstrtoul(buf, 0, &val);
> +		if (ret)
>   			goto out_unlock;
>   		spin_lock_bh(&p->br->lock);
>   		ret = brport_attr->store(p, val);

You should wait 24 hours before posting a new version.
The patch looks good to me, if there's a need for v3
please add my:

Acked-by: Nikolay Aleksandrov <razor@blackwall.org>

Cheers,
  Nik