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Message-ID: <3feb6514-de2c-4b95-b203-74362b3cc002@6wind.com>
Date:   Wed, 20 Jul 2022 10:26:03 +0200
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Reply-To: nicolas.dichtel@6wind.com
Subject: Re: [PATCH net-next] net: ipv6: avoid accepting values greater than 2
 for accept_untracked_na
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To:     Jaehee Park <jhpark1013@gmail.com>, netdev@vger.kernel.org
Cc:     davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org,
        dsahern@gmail.com, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, shuah@kernel.org, linux-kernel@vger.kernel.org,
        aajith@arista.com, roopa@nvidia.com, roopa.prabhu@gmail.com,
        aroulin@nvidia.com, sbrivio@redhat.com
References: <20220720065211.369241-1-jhpark1013@gmail.com>
From:   Nicolas Dichtel <nicolas.dichtel@6wind.com>
Organization: 6WIND
In-Reply-To: <20220720065211.369241-1-jhpark1013@gmail.com>
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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@gmail.com>
> Suggested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> Suggested-by: Roopa Prabhu <roopa@nvidia.com>
> ---
>  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