Re: [PATCH 3/3] soc: mediatek: pwrap: add mt6572 support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Unconditional dereference and access of `wrp->slave->dew_regs` in MT6572 clock initialization can cause a NULL pointer dereference or unintended PMIC register overwrite.
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--- Patch [3]: [PATCH 3/3] soc: mediatek: pwrap: add mt6572 support ---
commit 27b1606815262a3356b161758ca5a4ebb413b4ab
Author: Roman Vivchar <rva333@protonmail.com>

soc: mediatek: pwrap: add mt6572 support

This commit adds mt6572 registers and platform data for the pmic wrapper.
It reuses the mt2701 SoC-specific initialization function since they share
the same GPS_INTF settings.

> diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
> index a4b10b0a97cbb..4b8a5dc80a36e 100644
> --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
> +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c

[ ... ]

> @@ -1733,6 +1824,11 @@ static void pwrap_init_chip_select_ext(struct pmic_wrapper *wrp, u8 hext_write,
>  static int pwrap_common_init_reg_clock(struct pmic_wrapper *wrp)
>  {
>  	switch (wrp->master->type) {
> +	case PWRAP_MT6572:
> +		pwrap_writel(wrp, 0x8, PWRAP_RDDMY);
> +		pwrap_write(wrp, wrp->slave->dew_regs[PWRAP_DEW_RDDMY_NO], 0x8);

[Severity: High]
Could this unconditionally dereference wrp->slave->dew_regs if the configured
slave PMIC doesn't populate it?

If the mediatek,mt6572-pwrap device node is configured with a PMIC that
doesn't populate dew_regs (like PMIC_MT6380), or leaves PWRAP_DEW_RDDMY_NO
uninitialized (like PMIC_MT6397), this array lookup could either
dereference a NULL pointer or evaluate to 0x0. 

This could lead to a kernel panic during driver probe or an unintended
SPI write of 0x8 to PMIC register 0x0.

Would it be safer to validate the slave PMIC type or check that dew_regs is
present before accessing it here, similar to how it is handled for
PWRAP_MT6795 below?

> +		pwrap_init_chip_select_ext(wrp, 5, 0, 0, 0);
> +		break;
>  	case PWRAP_MT6795:
>  		if (wrp->slave->type == PMIC_MT6331) {

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260714-6572-pwrap-v1-0-d8e5a39cf7ef@protonmail.com?part=3