[patch v2] drm/amdgpu: missing bounds check in amdgpu_set_pp_force_state()

Dan Carpenter
2016-06-16T08:30:23Z

There is no limit on high "idx" can go. It should be less than
ARRAY_SIZE(data.states) which is 16.

The "data" variable wasn't declared in that scope so I shifted the code
around a bit to make it work. Also I made "idx" unsigned.

Fixes: f3898ea12fc1 ('drm/amd/powerplay: add some sysfs interfaces for powerplay.')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: make idx unsigned

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
index 589b36e..0e13d80 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
@@ -270,30 +270,28 @@ static ssize_t amdgpu_set_pp_force_state(struct device *dev,
struct drm_device *ddev = dev_get_drvdata(dev);
struct amdgpu_device *adev = ddev->dev_private;
enum amd_pm_state_type state = 0;
- long idx;
+ unsigned long idx;
int ret;

if (strlen(buf) = 1)
adev->pp_force_state_enabled = false;
- else {
- ret = kstrtol(buf, 0, &idx);
+ else if (adev->pp_enabled) {
+ struct pp_states_info data;

- if (ret) {
+ ret = kstrtoul(buf, 0, &idx);
+ if (ret || idx >= ARRAY_SIZE(data.states)) {
count = -EINVAL;
goto fail;
}

- if (adev->pp_enabled) {
- struct pp_states_info data;
- amdgpu_dpm_get_pp_num_states(adev, &data);
- state = data.states[idx];
- /* only set user selected power states */
- if (state != POWER_STATE_TYPE_INTERNAL_BOOT &&
- state != POWER_STATE_TYPE_DEFAULT) {
- amdgpu_dpm_dispatch_task(adev,
- AMD_PP_EVENT_ENABLE_USER_STATE, &state, NULL);
- adev->pp_force_state_enabled = true;
- }
+ amdgpu_dpm_get_pp_num_states(adev, &data);
+ state = data.states[idx];
+ /* only set user selected power states */
+ if (state != POWER_STATE_TYPE_INTERNAL_BOOT &&
+ state != POWER_STATE_TYPE_DEFAULT) {
+ amdgpu_dpm_dispatch_task(adev,
+ AMD_PP_EVENT_ENABLE_USER_STATE, &state, NULL);
+ adev->pp_force_state_enabled = true;
}
}