Re: [PATCH 02/49] regmap-irq: Fix offset/index mismatch in read_sub_irq_data()

[Matti Vaittinen]

On 6/20/22 23:05, Aidan MacDonald wrote:
> We need to divide the sub-irq status register offset by register
> stride to get an index for the status buffer to avoid an out of
> bounds write when the register stride is greater than 1.
>
> Fixes: a2d21848d921 ("regmap: regmap-irq: Add main status register support")
> Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx>
> ---
>   drivers/base/regmap/regmap-irq.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
> index 4f785bc7981c..a6db605707b0 100644
> --- a/drivers/base/regmap/regmap-irq.c
> +++ b/drivers/base/regmap/regmap-irq.c
> @@ -387,6 +387,7 @@ static inline int read_sub_irq_data(struct regmap_irq_chip_data *data,
>   		subreg = &chip->sub_reg_offsets[b];
>   		for (i = 0; i < subreg->num_regs; i++) {
>   			unsigned int offset = subreg->offset[i];
> +			unsigned int index = offset / map->reg_stride;
>   
>   			if (chip->not_fixed_stride)
>   				ret = regmap_read(map,
> @@ -395,7 +396,7 @@ static inline int read_sub_irq_data(struct regmap_irq_chip_data *data,
>   			else
>   				ret = regmap_read(map,
>   						chip->status_base + offset,
> -						&data->status_buf[offset]);
> +						&data->status_buf[index]);
>   
>   			if (ret)
>   				break;

Reviewed-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>

--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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