Date:   Mon, 20 Dec 2021 10:40:47 +0100
From:   Daniel Vetter <daniel@ffwll.ch>
To:     Brian Starkey <brian.starkey@arm.com>
Cc:     Jiasheng Jiang <jiasheng@iscas.ac.cn>, liviu.dudau@arm.com,
        airlied@linux.ie, daniel@ffwll.ch, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, nd@arm.com
Subject: Re: [PATCH] drm: mali-dp: potential dereference of null pointer
Message-ID: <YcBPn6ZTLbobErXj@phenom.ffwll.local>
Mail-Followup-To: Brian Starkey <brian.starkey@arm.com>,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>, liviu.dudau@arm.com,
        airlied@linux.ie, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, nd@arm.com
References: <20211214100837.46912-1-jiasheng@iscas.ac.cn>
 <20211214110202.unexcdiya3qhsvzc@000377403353>
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In-Reply-To: <20211214110202.unexcdiya3qhsvzc@000377403353>
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On Tue, Dec 14, 2021 at 11:02:02AM +0000, Brian Starkey wrote:
> Hi,
> 
> On Tue, Dec 14, 2021 at 06:08:37PM +0800, Jiasheng Jiang wrote:
> > The return value of kzalloc() needs to be checked.
> > To avoid use of null pointer '&state->base' in case of the
> > failure of alloc.
> > 
> > Fixes: 99665d072183 ("drm: mali-dp: add malidp_crtc_state struct")
> > Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> > ---
> 
> You can add my r-b to this one too. Thanks!

Are you (or someone else from arm) also pushing these? Otherwise they'll
get lost.
-Daniel

> 
> >  drivers/gpu/drm/arm/malidp_crtc.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
> > index 494075ddbef6..b5928b52e279 100644
> > --- a/drivers/gpu/drm/arm/malidp_crtc.c
> > +++ b/drivers/gpu/drm/arm/malidp_crtc.c
> > @@ -487,7 +487,10 @@ static void malidp_crtc_reset(struct drm_crtc *crtc)
> >  	if (crtc->state)
> >  		malidp_crtc_destroy_state(crtc, crtc->state);
> >  
> > -	__drm_atomic_helper_crtc_reset(crtc, &state->base);
> > +	if (state)
> > +		__drm_atomic_helper_crtc_reset(crtc, &state->base);
> > +	else
> > +		__drm_atomic_helper_crtc_reset(crtc, NULL);
> >  }
> >  
> >  static int malidp_crtc_enable_vblank(struct drm_crtc *crtc)
> > -- 
> > 2.25.1
> > 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch