RE: [PATCH] drm/amdgpu: fix null ptr access

["Quan, Evan" <Evan.Quan@amd.com>]

[AMD Official Use Only]



> -----Original Message-----
> From: Cui, Flora <Flora.Cui@amd.com>
> Sent: Thursday, January 13, 2022 2:58 PM
> To: amd-gfx@lists.freedesktop.org; Quan, Evan <Evan.Quan@amd.com>
> Cc: Cui, Flora <Flora.Cui@amd.com>
> Subject: [PATCH] drm/amdgpu: fix null ptr access
> 
> check null ptr first before access its element
> 
> Signed-off-by: Flora Cui <flora.cui@amd.com>
> ---
>  drivers/gpu/drm/amd/pm/amdgpu_dpm.c       | 2 +-
>  drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> index f0daa66f5b3d..5fc33893a68c 100644
> --- a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> +++ b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> @@ -463,7 +463,7 @@ int amdgpu_pm_load_smu_firmware(struct
> amdgpu_device *adev, uint32_t *smu_versio
>  	const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;
>  	int r = 0;
> 
> -	if (!pp_funcs->load_firmware)
> +	if (!pp_funcs || !pp_funcs->load_firmware)
>  		return 0;
[Quan, Evan] This seems fine to me.
> 
>  	mutex_lock(&adev->pm.mutex);
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> index 828cb932f6a9..aa640a9c6137 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> @@ -3281,7 +3281,7 @@ void amdgpu_smu_stb_debug_fs_init(struct
> amdgpu_device *adev)
> 
>  	struct smu_context *smu = adev->powerplay.pp_handle;
> 
> -	if (!smu->stb_context.stb_buf_size)
> +	if (!smu || !smu->stb_context.stb_buf_size)
>  		return;
[Quan, Evan] For this one, maybe as Lijo suggested, a check for "!adev->pm.dpm_enabled" in amdgpu_debugfs_pm_init() is better.

BR
Evan
> 
>  	debugfs_create_file_size("amdgpu_smu_stb_dump",
> --
> 2.25.1