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Date:   Fri, 25 Feb 2022 09:19:33 +0000
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Jia-Ju Bai <baijiaju1990@gmail.com>
Cc:     andrew@lunn.ch, hkallweit1@gmail.com, davem@davemloft.net,
        kuba@kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: phy: phylink: check the return value of
 phylink_validate()
Message-ID: <YhifJcE98boImuHJ@shell.armlinux.org.uk>
References: <20220225091246.22085-1-baijiaju1990@gmail.com>
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In-Reply-To: <20220225091246.22085-1-baijiaju1990@gmail.com>
Sender: Russell King (Oracle) <linux@armlinux.org.uk>
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On Fri, Feb 25, 2022 at 01:12:46AM -0800, Jia-Ju Bai wrote:
> The function phylink_validate() can fail, so its return value should be
> checked.
> 
> Fixes: 9525ae83959b ("phylink: add phylink infrastructure")
> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
>  drivers/net/phy/phylink.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index 420201858564..597f7579b29f 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c
> @@ -584,7 +584,9 @@ static int phylink_parse_fixedlink(struct phylink *pl,
>  
>  	bitmap_fill(pl->supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
>  	linkmode_copy(pl->link_config.advertising, pl->supported);
> -	phylink_validate(pl, pl->supported, &pl->link_config);
> +	ret = phylink_validate(pl, pl->supported, &pl->link_config);
> +	if (ret)
> +		return ret;

Completely unnecessary. pl->supported will be zero, leading to
phy_lookup_setting() failing.

>  	s = phy_lookup_setting(pl->link_config.speed, pl->link_config.duplex,
>  			       pl->supported, true);
> @@ -1261,7 +1263,11 @@ struct phylink *phylink_create(struct phylink_config *config,
>  
>  	bitmap_fill(pl->supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
>  	linkmode_copy(pl->link_config.advertising, pl->supported);
> -	phylink_validate(pl, pl->supported, &pl->link_config);
> +	ret = phylink_validate(pl, pl->supported, &pl->link_config);
> +	if (ret < 0) {
> +		kfree(pl);
> +		return ERR_PTR(ret);
> +	}

Again, intentional not to be checking here.

-- 
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