Re: [PATCH net-next] net: ipv6: avoid accepting values greater than 2 for accept_untracked_na

[Nicolas Dichtel]

Le 20/07/2022 à 08:52, Jaehee Park a écrit :
> The accept_untracked_na sysctl changed from a boolean to an integer
> when a new knob '2' was added. This patch provides a safeguard to avoid
> accepting values that are not defined in the sysctl. When setting a
> value greater than 2, the user will get an 'invalid argument' warning.
> 
> Signed-off-by: Jaehee Park <jhpark1013@xxxxxxxxx>
> Suggested-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
> Suggested-by: Roopa Prabhu <roopa@xxxxxxxxxx>
> ---
>  net/ipv6/addrconf.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index 6ed807b6c647..d3e77ea24f05 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -7042,9 +7042,9 @@ static const struct ctl_table addrconf_sysctl[] = {
>  		.data		= &ipv6_devconf.accept_untracked_na,
>  		.maxlen		= sizeof(int),
>  		.mode		= 0644,
> -		.proc_handler	= proc_dointvec,
> +		.proc_handler	= proc_dointvec_minmax,
>  		.extra1		= (void *)SYSCTL_ZERO,
> -		.extra2		= (void *)SYSCTL_ONE,
> +		.extra2		= (void *)SYSCTL_TWO,
Nit: the cast is useless:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/sysctl.h#n40


Regards,
Nicolas