Applied. Thanks!
On Tue, Apr 19, 2022 at 8:49 AM Keita Suzuki
<keitasuzuki.park@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> In function si_parse_power_table(), array adev->pm.dpm.ps and its member
> is allocated. If the allocation of each member fails, the array itself
> is freed and returned with an error code. However, the array is later
> freed again in si_dpm_fini() function which is called when the function
> returns an error.
>
> This leads to potential double free of the array adev->pm.dpm.ps, as
> well as leak of its array members, since the members are not freed in
> the allocation function and the array is not nulled when freed.
> In addition adev->pm.dpm.num_ps, which keeps track of the allocated
> array member, is not updated until the member allocation is
> successfully finished, this could also lead to either use after free,
> or uninitialized variable access in si_dpm_fini().
>
> Fix this by postponing the free of the array until si_dpm_fini() and
> increment adev->pm.dpm.num_ps everytime the array member is allocated.
>
> Signed-off-by: Keita Suzuki <keitasuzuki.park@xxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 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 caae54487f9c..079888229485 100644
> --- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
> @@ -7331,17 +7331,15 @@ static int si_parse_power_table(struct amdgpu_device *adev)
> if (!adev->pm.dpm.ps)
> return -ENOMEM;
> power_state_offset = (u8 *)state_array->states;
> - for (i = 0; i < state_array->ucNumEntries; i++) {
> + for (adev->pm.dpm.num_ps = 0, i = 0; i < state_array->ucNumEntries; i++) {
> u8 *idx;
> power_state = (union pplib_power_state *)power_state_offset;
> non_clock_array_index = power_state->v2.nonClockInfoIndex;
> non_clock_info = (struct _ATOM_PPLIB_NONCLOCK_INFO *)
> &non_clock_info_array->nonClockInfo[non_clock_array_index];
> ps = kzalloc(sizeof(struct si_ps), GFP_KERNEL);
> - if (ps == NULL) {
> - kfree(adev->pm.dpm.ps);
> + if (ps == NULL)
> return -ENOMEM;
> - }
> adev->pm.dpm.ps[i].ps_priv = ps;
> si_parse_pplib_non_clock_info(adev, &adev->pm.dpm.ps[i],
> non_clock_info,
> @@ -7363,8 +7361,8 @@ static int si_parse_power_table(struct amdgpu_device *adev)
> k++;
> }
> power_state_offset += 2 + power_state->v2.ucNumDPMLevels;
> + adev->pm.dpm.num_ps++;
> }
> - adev->pm.dpm.num_ps = state_array->ucNumEntries;
>
> /* fill in the vce power states */
> for (i = 0; i < adev->pm.dpm.num_of_vce_states; i++) {
> --
> 2.25.1
>
