Re: [PATCH 1/2] drm/amd: Fix more cases of NULL pointer deref at fini

[Lazar, Lijo]

On 06-Mar-26 3:35 AM, Mario Limonciello wrote:
I found more case that a NULL version causes problems.
Add NULL checks as applicable.

Fixes: 39fc2bc4da00 ("drm/amdgpu: Protect GPU register accesses in powergated state 
in some paths")
Signed-off-by: Mario Limonciello <mario.limoncie...@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 5 +++++
  1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index bc6f714e8763a..74cbe58484fe2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3463,6 +3463,9 @@ static void amdgpu_ip_block_hw_fini(struct 
amdgpu_ip_block *ip_block)
        struct amdgpu_device *adev = ip_block->adev;
        int r;
  
+	if (!ip_block->version)
+               return;
+

ip block versions are set during discovery phase itself. This is a very 
early init failure and ideally the fix should be not to call any fini 
for such an early failure.

Thanks,
Lijo

        if (!ip_block->version->funcs->hw_fini) {
                dev_err(adev->dev, "hw_fini of IP block <%s> not defined\n",
                        ip_block->version->funcs->name);
@@ -3496,6 +3499,8 @@ static void amdgpu_device_smu_fini_early(struct 
amdgpu_device *adev)
        for (i = 0; i < adev->num_ip_blocks; i++) {
                if (!adev->ip_blocks[i].status.hw)
                        continue;
+               if (!adev->ip_blocks[i].version)
+                       continue;
                if (adev->ip_blocks[i].version->type == AMD_IP_BLOCK_TYPE_SMC) {
                        amdgpu_ip_block_hw_fini(&adev->ip_blocks[i]);
                        break;