[PATCH] drm/amd/pm: fix a double-free in si_dpm_init

[Alex Deucher]

Applied.  Thanks!

On Thu, Dec 14, 2023 at 10:59 AM Zhipeng Lu <alexious at zju.edu.cn> wrote:
>
> When the allocation of
> adev->pm.dpm.dyn_state.vddc_dependency_on_dispclk.entries fails,
> amdgpu_free_extended_power_table is called to free some fields of adev.
> However, when the control flow returns to si_dpm_sw_init, it goes to
> label dpm_failed and calls si_dpm_fini, which calls
> amdgpu_free_extended_power_table again and free those fields again. Thus
> a double-free is triggered.
>
> Fixes: 841686df9f7d ("drm/amdgpu: add SI DPM support (v4)")
> Signed-off-by: Zhipeng Lu <alexious at zju.edu.cn>
> ---
>  drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> index fc8e4ac6c8e7..df4f20293c16 100644
> --- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> @@ -7379,10 +7379,9 @@ static int si_dpm_init(struct amdgpu_device *adev)
>                 kcalloc(4,
>                         sizeof(struct amdgpu_clock_voltage_dependency_entry),
>                         GFP_KERNEL);
> -       if (!adev->pm.dpm.dyn_state.vddc_dependency_on_dispclk.entries) {
> -               amdgpu_free_extended_power_table(adev);
> +       if (!adev->pm.dpm.dyn_state.vddc_dependency_on_dispclk.entries)
>                 return -ENOMEM;
> -       }
> +
>         adev->pm.dpm.dyn_state.vddc_dependency_on_dispclk.count = 4;
>         adev->pm.dpm.dyn_state.vddc_dependency_on_dispclk.entries[0].clk = 0;
>         adev->pm.dpm.dyn_state.vddc_dependency_on_dispclk.entries[0].v = 0;
> --
> 2.34.1
>