Re: [PATCH v2] firmware: vpd: Fix section enabled flag on vpd_section_destroy

[Guenter Roeck <linux@roeck-us.net>]

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
>