Re: [PATCH net 1/4] net-sysfs: check device is present when showing carrier

[Shigeru Yoshida]

Hi Jamie,

On Wed, 24 Jul 2024 11:46:50 +1000, Jamie Bainbridge wrote:
> A sysfs reader can race with a device reset or removal.
> 
> This was fixed for speed_show with commit 4224cfd7fb65 ("net-sysfs: add
> check for netdevice being present to speed_show") so add the same check
> to carrier_show.
> 
> Fixes: facd15dfd691 ("net: core: synchronize link-watch when carrier is queried")
> 
> Signed-off-by: Jamie Bainbridge <jamie.bainbridge@xxxxxxxxx>

nit: When resubmitting your fix, there is no need for a blank line
     between the Fixes and SOB tags.

Thanks,
Shigeru

> ---
>  net/core/net-sysfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> index 0e2084ce7b7572bff458ed7e02358d9258c74628..7fabe5afa3012ecad6551e12f478b755952933b8 100644
> --- a/net/core/net-sysfs.c
> +++ b/net/core/net-sysfs.c
> @@ -206,7 +206,7 @@ static ssize_t carrier_show(struct device *dev,
>  	if (!rtnl_trylock())
>  		return restart_syscall();
>  
> -	if (netif_running(netdev)) {
> +	if (netif_running(netdev) && netif_device_present(netdev)) {
>  		/* Synchronize carrier state with link watch,
>  		 * see also rtnl_getlink().
>  		 */
> -- 
> 2.39.2
> 
>