[PATCH v2] pinctrl: mediatek: eint: Fix invalid pointer dereference for v1 platforms

[AngeloGioacchino Del Regno]

Il 20/05/25 23:15, Nícolas F. R. A. Prado ha scritto:
> Commit 3ef9f710efcb ("pinctrl: mediatek: Add EINT support for multiple
> addresses") introduced an access to the 'soc' field of struct
> mtk_pinctrl in mtk_eint_do_init() and for that an include of
> pinctrl-mtk-common-v2.h.
> 
> However, pinctrl drivers relying on the v1 common driver include
> pinctrl-mtk-common.h instead, which provides another definition of
> struct mtk_pinctrl that does not contain an 'soc' field.
> 
> Since mtk_eint_do_init() can be called both by v1 and v2 drivers, it
> will now try to dereference an invalid pointer when called on v1
> platforms. This has been observed on Genio 350 EVK (MT8365), which
> crashes very early in boot (the kernel trace can only be seen with
> earlycon).
> 
> In order to fix this, since 'struct mtk_pinctrl' was only needed to get
> a 'struct mtk_eint_pin', make 'struct mtk_eint_pin' a parameter
> of mtk_eint_do_init() so that callers need to supply it, removing
> mtk_eint_do_init()'s dependency on any particular 'struct mtk_pinctrl'.
> 
> Fixes: 3ef9f710efcb ("pinctrl: mediatek: Add EINT support for multiple addresses")
> Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
> Signed-off-by: Nícolas F. R. A. Prado <nfraprado at collabora.com>
> ---
> Changes in v2:
> - Completely changed approach to make mtk_eint_pin a parameter of
>    mtk_eint_do_init() as suggested by Angelo
> - Link to v1: https://lore.kernel.org/r/20250519-genio-350-eint-null-ptr-deref-fix-v1-1-07445d6d22c3@collabora.com
> ---
>   drivers/pinctrl/mediatek/mtk-eint.c              | 26 ++++++++++--------------
>   drivers/pinctrl/mediatek/mtk-eint.h              |  5 +++--
>   drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c |  2 +-
>   drivers/pinctrl/mediatek/pinctrl-mtk-common.c    |  2 +-
>   4 files changed, 16 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/pinctrl/mediatek/mtk-eint.c b/drivers/pinctrl/mediatek/mtk-eint.c
> index 16af6a47028e67bb53db4041a37ebbbb8b9a1e43..d906a5e4101fb10968035fc48e9cf4a444d063a9 100644
> --- a/drivers/pinctrl/mediatek/mtk-eint.c
> +++ b/drivers/pinctrl/mediatek/mtk-eint.c
> @@ -22,7 +22,6 @@
>   #include <linux/platform_device.h>
>   
>   #include "mtk-eint.h"
> -#include "pinctrl-mtk-common-v2.h"
>   
>   #define MTK_EINT_EDGE_SENSITIVE           0
>   #define MTK_EINT_LEVEL_SENSITIVE          1
> @@ -505,10 +504,9 @@ int mtk_eint_find_irq(struct mtk_eint *eint, unsigned long eint_n)
>   }
>   EXPORT_SYMBOL_GPL(mtk_eint_find_irq);
>   
> -int mtk_eint_do_init(struct mtk_eint *eint)
> +int mtk_eint_do_init(struct mtk_eint *eint, struct mtk_eint_pin *eint_pin)
>   {
>   	unsigned int size, i, port, virq, inst = 0;
> -	struct mtk_pinctrl *hw = (struct mtk_pinctrl *)eint->pctl;
>   
>   	/* If clients don't assign a specific regs, let's use generic one */
>   	if (!eint->regs)
> @@ -519,7 +517,15 @@ int mtk_eint_do_init(struct mtk_eint *eint)
>   	if (!eint->base_pin_num)
>   		return -ENOMEM;
>   
> -	if (eint->nbase == 1) {

Okay, dropping the nbase == 1 is sane, but that statement was actually documenting
the fact that *eint_pin is used only for multi-base EINT case, so please add those
comments:

> +	if (eint_pin) {

		/* EINT with multiple bases */

> +		eint->pins = eint_pin;
> +		for (i = 0; i < eint->hw->ap_num; i++) {
> +			inst = eint->pins[i].instance;
> +			if (inst >= eint->nbase)
> +				continue;
> +			eint->base_pin_num[inst]++;
> +		}
> +	} else {

		/* Single base EINT */

...after which:

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>

Thanks for fixing this!