linux-kernel - Re: [PATCH v2 3/4] ARM: amba: Don't read past the end of sysfs "driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 25 Apr 2018 08:56:54 -0700
From:   Todd Kjos <tkjos@...roid.com>
To:     Geert Uytterhoeven <geert+renesas@...der.be>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Russell King <linux@...linux.org.uk>,
        Adrian Salido <salidoa@...gle.com>,
        Nicolai Stange <nstange@...e.de>,
        Sasha Levin <Alexander.Levin@...rosoft.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 3/4] ARM: amba: Don't read past the end of sysfs
 "driver_override" buffer

Reviewed-by: Todd Kjos <tkjos@...roid.com>

On Tue, Apr 10, 2018 at 6:21 AM, Geert Uytterhoeven
<geert+renesas@...der.be> wrote:
> When printing the driver_override parameter when it is 4095 and 4094
> bytes long, the printing code would access invalid memory because we
> need count + 1 bytes for printing.
>
> Cfr. commits 4efe874aace57dba ("PCI: Don't read past the end of sysfs
> "driver_override" buffer") and bf563b01c2895a4b ("driver core: platform:
> Don't read past the end of "driver_override" buffer").
>
> Fixes: 3cf385713460eb2b ("ARM: 8256/1: driver coamba: add device binding path 'driver_override'")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
> ---
>  drivers/amba/bus.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
> index 36c5653ced5742b7..4a3ac31c07d0ee49 100644
> --- a/drivers/amba/bus.c
> +++ b/drivers/amba/bus.c
> @@ -84,7 +84,8 @@ static ssize_t driver_override_store(struct device *_dev,
>         struct amba_device *dev = to_amba_device(_dev);
>         char *driver_override, *old, *cp;
>
> -       if (count > PATH_MAX)
> +       /* We need to keep extra room for a newline */
> +       if (count >= (PAGE_SIZE - 1))
>                 return -EINVAL;
>
>         driver_override = kstrndup(buf, count, GFP_KERNEL);
> --
> 2.7.4
>