From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guido =?iso-8859-1?Q?G=FCnther?= Date: Fri, 18 Sep 2020 16:22:49 +0000 Subject: Re: [PATCH][next] drm/panel: fix null pointer dereference on pointer mode Message-Id: <20200918162249.GA292461@bogon.m.sigxcpu.org> List-Id: References: <20200918155136.28958-1-colin.king@canonical.com> In-Reply-To: <20200918155136.28958-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Colin King Cc: Purism Kernel Team , David Airlie , kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Thierry Reding , Sam Ravnborg Hi, On Fri, Sep 18, 2020 at 04:51:36PM +0100, Colin King wrote: > From: Colin Ian King > > Currently a null pointer check on pointer mode is passing mode to > function drm_mode_vrefresh and this causes a null pointer dereference > on mode. Fix this by not calling drm_mode_vrefresh since the call > is only required for error reporting. > > Addresses-Coverity: ("Dereference after null check") > Fixes: 72967d5616d3 ("drm/panel: Add panel driver for the Mantix MLAF057WE51-X DSI panel") > Signed-off-by: Colin Ian King > --- > drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c b/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c > index 3482e28e30fc..be4761a643f9 100644 > --- a/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c > +++ b/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c > @@ -202,9 +202,8 @@ static int mantix_get_modes(struct drm_panel *panel, > > mode = drm_mode_duplicate(connector->dev, &default_mode); > if (!mode) { > - dev_err(ctx->dev, "Failed to add mode %ux%u@%u\n", > - default_mode.hdisplay, default_mode.vdisplay, > - drm_mode_vrefresh(mode)); > + dev_err(ctx->dev, "Failed to add mode %ux%u\n", > + default_mode.hdisplay, default_mode.vdisplay); > return -ENOMEM; > } drm_mode_vrefresh(&default_mode) gives some more clue what's going on - I have had a fix queued up in my tree already but if you send a v2 that's fine. Thanks! -- Guido > > -- > 2.27.0 >