| Message ID | 20221120142737.17519-1-LinoSanfilippo@gmx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/vc4: Fix NULL pointer access in vc4_platform_drm_probe() | expand |
Hi Lino On Sun, 20 Nov 2022 at 15:26, Lino Sanfilippo <LinoSanfilippo@gmx.de> wrote: > > From: Lino Sanfilippo <l.sanfilippo@kunbus.com> > > In vc4_platform_drm_probe() function vc4_match_add_drivers() is called to > find component matches for the component drivers. If no such match is found > the passed variable "match" is still NULL after the function returns. This would imply a very strange device tree that has bothered to add the drm device but none of the devices that are required to run the DRM pipeline, but avoiding a NULL deref is certainly preferable. > Do not pass "match" to component_master_add_with_match() in this case since > this results in a NULL pointer access as soon as match->num is used to > allocate a component_match array. Instead return with -ENODEV from the > drivers probe function. > > Fixes: c8b75bca92cb ("drm/vc4: Add KMS support for Raspberry Pi.") > Cc: stable@vger.kernel.org > Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com> > --- > drivers/gpu/drm/vc4/vc4_drv.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c > index 2027063fdc30..2e53d7f8ad44 100644 > --- a/drivers/gpu/drm/vc4/vc4_drv.c > +++ b/drivers/gpu/drm/vc4/vc4_drv.c > @@ -437,6 +437,9 @@ static int vc4_platform_drm_probe(struct platform_device *pdev) > vc4_match_add_drivers(dev, &match, > component_drivers, ARRAY_SIZE(component_drivers)); > > + if (!match) > + return -ENODEV; > + > return component_master_add_with_match(dev, &vc4_drm_ops, match); > } > > > base-commit: 30a0b95b1335e12efef89dd78518ed3e4a71a763 > -- > 2.36.1 >
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c index 2027063fdc30..2e53d7f8ad44 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.c +++ b/drivers/gpu/drm/vc4/vc4_drv.c @@ -437,6 +437,9 @@ static int vc4_platform_drm_probe(struct platform_device *pdev) vc4_match_add_drivers(dev, &match, component_drivers, ARRAY_SIZE(component_drivers)); + if (!match) + return -ENODEV; + return component_master_add_with_match(dev, &vc4_drm_ops, match); }