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Date:   Tue, 24 Jul 2018 08:55:46 -0700
From:   Guenter Roeck <linux@roeck-us.net>
To:     Anton Vasilyev <vasilyev@ispras.ru>
Cc:     Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Samuel Holland <samuel@sholland.org>,
        Pan Bian <bianpan2016@163.com>, linux-kernel@vger.kernel.org,
        ldv-project@linuxtesting.org
Subject: Re: [PATCH v2] firmware: vpd: Fix section enabled flag on
 vpd_section_destroy
Message-ID: <20180724155546.GB917@roeck-us.net>
References: <20180723183927.GH100814@dtor-ws>
 <20180724151038.14838-1-vasilyev@ispras.ru>
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On Tue, Jul 24, 2018 at 06:10:38PM +0300, Anton Vasilyev wrote:
> static struct ro_vpd and rw_vpd are initialized by vpd_sections_init()
> in vpd_probe() based on header's ro and rw sizes.
> In vpd_remove() vpd_section_destroy() performs deinitialization based
> on enabled flag, which is set to true by vpd_sections_init().
> This leads to call of vpd_section_destroy() on already destroyed section
> for probe-release-probe-release sequence if first probe performs
> ro_vpd initialization and second probe does not initialize it.
> 
> The patch adds changing enabled flag on vpd_section_destroy and adds
> cleanup on the error path of vpd_sections_init.
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> v2: add cleanup on the error path of vpd_sections_init
> ---
>  drivers/firmware/google/vpd.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/google/vpd.c b/drivers/firmware/google/vpd.c
> index e9db895916c3..1aa67bb5d8c0 100644
> --- a/drivers/firmware/google/vpd.c
> +++ b/drivers/firmware/google/vpd.c
> @@ -246,6 +246,7 @@ static int vpd_section_destroy(struct vpd_section *sec)
>  		sysfs_remove_bin_file(vpd_kobj, &sec->bin_attr);
>  		kfree(sec->raw_name);
>  		memunmap(sec->baseaddr);
> +		sec->enabled = false;
>  	}
>  
>  	return 0;
> @@ -279,8 +280,10 @@ static int vpd_sections_init(phys_addr_t physaddr)
>  		ret = vpd_section_init("rw", &rw_vpd,
>  				       physaddr + sizeof(struct vpd_cbmem) +
>  				       header.ro_size, header.rw_size);
> -		if (ret)
> +		if (ret) {
> +			vpd_section_destroy(&ro_vpd);
>  			return ret;
> +		}
>  	}
>  
>  	return 0;
> -- 
> 2.18.0
>