2023-12-14 16:57:58

by Zhipeng Lu

Subject: [PATCH] drivers/amd/pm: fix a use-after-free in kv_parse_power_table

When ps allocated by kzalloc equals to NULL, kv_parse_power_table
frees adev->pm.dpm.ps that allocated before. However, after the control
flow goes through the following call chains:

kv_parse_power_table
|-> kv_dpm_init
|-> kv_dpm_sw_init
|-> kv_dpm_fini

The adev->pm.dpm.ps is used in the for loop of kv_dpm_fini after its
first free in kv_parse_power_table and causes a use-after-free bug.

Fixes: a2e73f56fa62 ("drm/amdgpu: Add support for CIK parts")
Signed-off-by: Zhipeng Lu <[email protected]>
---
drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
index 5d28c951a319..5cb4725c773f 100644
--- a/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
+++ b/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
@@ -2735,10 +2735,8 @@ static int kv_parse_power_table(struct amdgpu_device *adev)
non_clock_info = (struct _ATOM_PPLIB_NONCLOCK_INFO *)
&non_clock_info_array->nonClockInfo[non_clock_array_index];
ps = kzalloc(sizeof(struct kv_ps), GFP_KERNEL);
- if (ps == NULL) {
- kfree(adev->pm.dpm.ps);
+ if (ps == NULL)
return -ENOMEM;
- }
adev->pm.dpm.ps[i].ps_priv = ps;
k = 0;
idx = (u8 *)&power_state->v2.clockInfoIndex[0];
--
2.34.1

2023-12-14 17:06:56

by Alex Deucher

Subject: Re: [PATCH] drivers/amd/pm: fix a use-after-free in kv_parse_power_table

Applied. Thanks!

On Thu, Dec 14, 2023 at 11:57 AM Zhipeng Lu <[email protected]> wrote:
>
> When ps allocated by kzalloc equals to NULL, kv_parse_power_table
> frees adev->pm.dpm.ps that allocated before. However, after the control
> flow goes through the following call chains:
>
> kv_parse_power_table
> |-> kv_dpm_init
> |-> kv_dpm_sw_init
> |-> kv_dpm_fini
>
> The adev->pm.dpm.ps is used in the for loop of kv_dpm_fini after its
> first free in kv_parse_power_table and causes a use-after-free bug.
>
> Fixes: a2e73f56fa62 ("drm/amdgpu: Add support for CIK parts")
> Signed-off-by: Zhipeng Lu <[email protected]>
> ---
> drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
> index 5d28c951a319..5cb4725c773f 100644
> --- a/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
> +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
> @@ -2735,10 +2735,8 @@ static int kv_parse_power_table(struct amdgpu_device *adev)
> non_clock_info = (struct _ATOM_PPLIB_NONCLOCK_INFO *)
> &non_clock_info_array->nonClockInfo[non_clock_array_index];
> ps = kzalloc(sizeof(struct kv_ps), GFP_KERNEL);
> - if (ps == NULL) {
> - kfree(adev->pm.dpm.ps);
> + if (ps == NULL)
> return -ENOMEM;
> - }
> adev->pm.dpm.ps[i].ps_priv = ps;
> k = 0;
> idx = (u8 *)&power_state->v2.clockInfoIndex[0];
> --
> 2.34.1
>