On 7/17/2024 5:25 PM, Dan Carpenter wrote:
On Wed, Jul 17, 2024 at 05:05:55PM +0200, Nirmoy Das wrote:
On 7/12/2024 11:41 PM, Jonathan Cavitt wrote:
Prevent a NULL pointer access in intel_memory_regions_hw_probe.
Fixes: 05da7d9f717b ("drm/i915/gem: Downgrade stolen lmem setup warning")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_memory_region.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index 172dfa7c3588b..d40ee1b42110a 100644
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -368,8 +368,10 @@ int intel_memory_regions_hw_probe(struct drm_i915_private *i915)
goto out_cleanup;
}
- mem->id = i;
- i915->mm.regions[i] = mem;
There is a check for mem just before that. You could use IS_ERR_OR_NULL(mem)
instead of IS_ERR().
An error pointer return is normally completely different from a NULL
return in how it's handled.
intel_memory_regions_driver_release() skipped my eyes in the cleanup path.
Here NULL is a special kind of success. I
wrote a blog about this.
https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
I am the perfect target audience for this blog post :)
Thanks,
Nirmoy
regards,
dan carpenter
