Re: [PATCH] drm/amdgpu: Fix NULL dereference in amdgpu_ualink_info_set_accel_state

[Lazar, Lijo]

On 15-Sep-26 12:11 PM, Srinivasan Shanmugam wrote:

Commit bb2545b351c3 ("drm/amdgpu: Improve ualink state transitions")
introduced an access to info->accel_state before checking whether info
is NULL.

Move the access after the NULL check to avoid a potential NULL pointer
dereference.

Fixes: bb2545b351c3 ("drm/amdgpu: Improve ualink state transitions")
Reported-by: Dan Carpenter <erro...@gmail.com>
Cc: Lijo Lazar <lijo.la...@amd.com>
Cc: Felix Kuehling <felix.kuehl...@amd.com>
Cc: Christian König <christian.koe...@amd.com>
Cc: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmu...@amd.com>

Reviewed-by: Lijo Lazar <lijo.la...@amd.com>

Thanks,
Lijo

---
  drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c | 4 +++-
  1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
index f4a4432c2c5d..3b0d5138a349 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
@@ -161,7 +161,7 @@ amdgpu_ualink_info_set_accel_state(struct amdgpu_device 
*adev,
                                   struct amdgpu_ualink_info *info,
                                   enum psp_gfx_ual_config_state cfg_state)
  {
-       enum amdgpu_ualink_accel_state cur = info->accel_state;
+       enum amdgpu_ualink_accel_state cur;
        enum amdgpu_ualink_accel_state target;
        bool ppod_validated;
        bool vpod_validated;
@@ -169,6 +169,8 @@ amdgpu_ualink_info_set_accel_state(struct amdgpu_device 
*adev,
        if (!info)
                return;

+ cur = info->accel_state;

+
        ppod_validated = cur >= AMDGPU_UALINK_ACCEL_STATE_PPOD_CONFIGURED &&
                         cur <= AMDGPU_UALINK_ACCEL_STATE_ACTIVE;
        vpod_validated = cur >= AMDGPU_UALINK_ACCEL_STATE_VPOD_CONFIGURED &&