drm/amd/pm: fix variable dereferenced issue in amdgpu_device_attr_create()

From Yang Wang
f27dff881f0b8f1a5bc64d48a19802dd520bc482 in linux-6.1.y/6.1.53
25e6373a5b8efc623443f2699d2b929bf3067d76 in mainline linux

diff --git a/sys/dev/pci/drm/amd/pm/amdgpu_pm.c b/sys/dev/pci/drm/amd/pm/amdgpu_pm.c
index ef5f21e..134bdb4 100644 (file)
--- a/sys/dev/pci/drm/amd/pm/amdgpu_pm.c
+++ b/sys/dev/pci/drm/amd/pm/amdgpu_pm.c
@@ -2074,15 +2074,19 @@ static int amdgpu_device_attr_create(struct amdgpu_device *adev,
                                     uint32_t mask, struct list_head *attr_list)
 {
        int ret = 0;
-       struct device_attribute *dev_attr = &attr->dev_attr;
-       const char *name = dev_attr->attr.name;
        enum amdgpu_device_attr_states attr_states = ATTR_STATE_SUPPORTED;
        struct amdgpu_device_attr_entry *attr_entry;
+       struct device_attribute *dev_attr;
+       const char *name;
 
        int (*attr_update)(struct amdgpu_device *adev, struct amdgpu_device_attr *attr,
                           uint32_t mask, enum amdgpu_device_attr_states *states) = default_attr_update;
 
-       BUG_ON(!attr);
+       if (!attr)
+               return -EINVAL;
+
+       dev_attr = &attr->dev_attr;
+       name = dev_attr->attr.name;
 
        attr_update = attr->attr_update ? attr->attr_update : default_attr_update;