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