linux-kernel - Re: [PATCH] drm/panel: fix null pointer dereference in hx83102_get

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]

Message-ID: <CAHwB_N+1a9pWTVZmWb6tDTR0S1G5tCj7zJx9xaOL_tBTS5oTtQ@mail.gmail.com>
Date: Thu, 22 Aug 2024 18:01:59 +0800
From: cong yang <yangcong5@...qin.corp-partner.google.com>
To: Charles Han <hanchunchao@...pur.com>
Cc: neil.armstrong@...aro.org, quic_jesszhan@...cinc.com, 
	maarten.lankhorst@...ux.intel.com, mripard@...nel.org, tzimmermann@...e.de, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
	liuyanming@...system.com, Douglas Anderson <dianders@...omium.org>
Subject: Re: [PATCH] drm/panel: fix null pointer dereference in hx83102_get_modes

Hi,

Charles Han <hanchunchao@...pur.com> 于2024年8月22日周四 17:34写道：
>
> In hx83102_get_modes(), the return value of drm_mode_duplicate()
> is assigned to mode, which will lead to a possible NULL
> pointer dereference on failure of drm_mode_duplicate(). Add a
> check to avoid npd.
>
> Fixes: 0ef94554dc40 ("drm/panel: himax-hx83102: Break out as separate driver")
>
> Signed-off-by: Charles Han <hanchunchao@...pur.com>
> ---
>  drivers/gpu/drm/panel/panel-himax-hx83102.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/panel/panel-himax-hx83102.c b/drivers/gpu/drm/panel/panel-himax-hx83102.c
> index 6e4b7e4644ce..7c2a5e9b7fb3 100644
> --- a/drivers/gpu/drm/panel/panel-himax-hx83102.c
> +++ b/drivers/gpu/drm/panel/panel-himax-hx83102.c
> @@ -565,6 +565,10 @@ static int hx83102_get_modes(struct drm_panel *panel,
>         struct drm_display_mode *mode;
>
>         mode = drm_mode_duplicate(connector->dev, m);
> +       if (!mode) {
> +               dev_err(&ctx->dsi->dev, "bad mode or failed to add mode\n");
> +               return -EINVAL;
> +       }

 In my V2 series, Doug suggested:
"nit: no need for an error message when drm_mode_duplicate() fails.
It is incredibly unlikely that the allocation will fail and the Linux"

https://lore.kernel.org/all/CAD=FV=V2O2aFDVn5CjbXfgcOLkmNp-G3ChVqQKouB2mDB+NZug@mail.gmail.com/

>
>         mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
>         drm_mode_set_name(mode);
> --
> 2.31.1
>