Re: Potential NULL pointer deference in drm/amdgpu

From: Koenig, Christian
Date: Thu Oct 10 2019 - 02:52:34 EST

Hi Yizhuo,

Am 10.10.19 um 07:09 schrieb Yizhuo Zhai:
> Hi All:
> drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c:
> The function to_amdgpu_fence() could return NULL, but callers
> in this file does not check the return value but directly dereference it,
> which seems potentially unsafe.
> Such callers include amdgpu_fence_get_timeline_name(),
> amdgpu_fence_enable_signaling() and amdgpu_fence_free().

That is expected behavior and no need to worry.

The functions in amdgpu_fence.c are the callbacks to implement
amdgpu_fence_ops. The function to_amdgpu_fence() checks if the ops of
the fence are amdgpu_fence_ops, so it is guaranteed that the functions
are called with an amdgpu_fence structure.