2023-12-14 15:59:49

by Zhipeng Lu

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

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 <[email protected]>
---
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

2023-12-14 17:03:50

by Alex Deucher

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

Applied. Thanks!

On Thu, Dec 14, 2023 at 10:59 AM Zhipeng Lu <[email protected]> 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 <[email protected]>
> ---
> 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
>