Re: [PATCH] drm/i915: Allow NULL memory region

[Nirmoy Das]

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.carpen...@linaro.org>
Signed-off-by: Jonathan Cavitt <jonathan.cav...@intel.com>
---
  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().


Regards,

Nirmoy

+               if (mem) { /* Skip on non-fatal errors */
+                       mem->id = i;
+                       i915->mm.regions[i] = mem;
+               }
        }
  
  	for (i = 0; i < ARRAY_SIZE(i915->mm.regions); i++) {