From: Daniel Vetter <daniel@ffwll.ch>
To: Kangjie Lu <kjlu@umn.edu>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] gma/gma500: fix a memory disclosure bug due to uninitialized bytes
Date: Tue, 22 Oct 2019 10:56:30 +0200 [thread overview]
Message-ID: <20191022085630.GZ11828@phenom.ffwll.local> (raw)
In-Reply-To: <20191018042953.31099-1-kjlu@umn.edu>
On Thu, Oct 17, 2019 at 11:29:53PM -0500, Kangjie Lu wrote:
> `best_clock` is an object that may be sent out. Object `clock`
> contains uninitialized bytes that are copied to `best_clock`,
> which leads to memory disclosure and information leak.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
> drivers/gpu/drm/gma500/cdv_intel_display.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/gma500/cdv_intel_display.c b/drivers/gpu/drm/gma500/cdv_intel_display.c
> index f56852a503e8..8b784947ed3b 100644
> --- a/drivers/gpu/drm/gma500/cdv_intel_display.c
> +++ b/drivers/gpu/drm/gma500/cdv_intel_display.c
> @@ -405,6 +405,8 @@ static bool cdv_intel_find_dp_pll(const struct gma_limit_t *limit,
> struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
> struct gma_clock_t clock;
>
> + memset(&clock, 0, sizeof(clock));
I guess whatever analyzer you use for this doesn't see past the ->clock
vfunc call, so shouldn't be a real issue. Also, it's not an information
disclosure since we only ever leak this to other kernel code, never
userspace.
But I guess doesn't hurt, so applied.
-Daniel
> +
> switch (refclk) {
> case 27000:
> if (target < 200000) {
> --
> 2.17.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
prev parent reply other threads:[~2019-10-22 8:56 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-18 4:29 [PATCH] gma/gma500: fix a memory disclosure bug due to uninitialized bytes Kangjie Lu
2019-10-22 8:56 ` Daniel Vetter [this message]
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