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Date:   Thu, 23 Jun 2022 12:03:43 +0300
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Subject: Re: [PATCH 02/49] regmap-irq: Fix offset/index mismatch in
 read_sub_irq_data()
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To:     Aidan MacDonald <aidanmacdonald.0x0@gmail.com>, broonie@kernel.org
Cc:     agross@kernel.org, bjorn.andersson@linaro.org,
        srinivas.kandagatla@linaro.org, bgoswami@codeaurora.org,
        gregkh@linuxfoundation.org, rafael@kernel.org,
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        tglx@linutronix.de, maz@kernel.org, lee.jones@linaro.org,
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References: <20220620200644.1961936-1-aidanmacdonald.0x0@gmail.com>
 <20220620200644.1961936-3-aidanmacdonald.0x0@gmail.com>
From:   Matti Vaittinen <mazziesaccount@gmail.com>
In-Reply-To: <20220620200644.1961936-3-aidanmacdonald.0x0@gmail.com>
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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@gmail.com>
> ---
>   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@gmail.com>

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

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