drm/amd: Fix NULL pointer dereference in device cleanup

When GPU initialization fails due to an unsupported HW block
IP blocks may have a NULL version pointer. During cleanup in
amdgpu_device_fini_hw, the code calls amdgpu_device_set_pg_state and
amdgpu_device_set_cg_state which iterate over all IP blocks and access
adev->ip_blocks[i].version without NULL checks, leading to a kernel
NULL pointer dereference.

Add NULL checks for adev->ip_blocks[i].version in both
amdgpu_device_set_cg_state and amdgpu_device_set_pg_state to prevent
dereferencing NULL pointers during GPU teardown when initialization has
failed.

Fixes: 39fc2bc4da00 ("drm/amdgpu: Protect GPU register accesses in powergated state in some paths")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit b7ac77468cda92eecae560b05f62f997a12fe2f2)
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 3e19b51a276380588951bee1a66c12d05b2393e0..10b10bac8b18ae41340792c23bf6b6dd3cddb7f9 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3247,6 +3247,8 @@ int amdgpu_device_set_cg_state(struct amdgpu_device *adev,
                i = state == AMD_CG_STATE_GATE ? j : adev->num_ip_blocks - j - 1;
                if (!adev->ip_blocks[i].status.late_initialized)
                        continue;
+               if (!adev->ip_blocks[i].version)
+                       continue;
                /* skip CG for GFX, SDMA on S0ix */
                if (adev->in_s0ix &&
                    (adev->ip_blocks[i].version->type == AMD_IP_BLOCK_TYPE_GFX ||
@@ -3286,6 +3288,8 @@ int amdgpu_device_set_pg_state(struct amdgpu_device *adev,
                i = state == AMD_PG_STATE_GATE ? j : adev->num_ip_blocks - j - 1;
                if (!adev->ip_blocks[i].status.late_initialized)
                        continue;
+               if (!adev->ip_blocks[i].version)
+                       continue;
                /* skip PG for GFX, SDMA on S0ix */
                if (adev->in_s0ix &&
                    (adev->ip_blocks[i].version->type == AMD_IP_BLOCK_TYPE_GFX ||