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

[AngeloGioacchino Del Regno]

Il 21/05/25 15:53, AngeloGioacchino Del Regno ha scritto:
> 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 at 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!
> 

Just acknowledged that Linus already picked this one.

It's fine either way, no worries.

Cheers,
Angelo