Re: [PATCH] power: supply: max17040: fix null-ptr-deref in max17040_probe()

[Krzysztof Kozlowski]

On 08/10/2021 08:31, Yang Yingliang wrote:
> Add check the return value of devm_regmap_init_i2c(), otherwise
> later access may cause null-ptr-deref as follows:
> 
> KASAN: null-ptr-deref in range [0x0000000000000360-0x0000000000000367]
> RIP: 0010:regmap_read+0x33/0x170
> Call Trace:
>   max17040_probe+0x61b/0xff0 [max17040_battery]
>  ? write_comp_data+0x2a/0x90
>  ? max17040_set_property+0x1d0/0x1d0 [max17040_battery]
>  ? tracer_hardirqs_on+0x33/0x520
>  ? __sanitizer_cov_trace_pc+0x1d/0x50
>  ? _raw_spin_unlock_irqrestore+0x4b/0x60
>  ? trace_hardirqs_on+0x63/0x2d0
>  ? write_comp_data+0x2a/0x90
>  ? __sanitizer_cov_trace_pc+0x1d/0x50
>  ? max17040_set_property+0x1d0/0x1d0 [max17040_battery]
>  i2c_device_probe+0xa31/0xbe0
> 
> Fixes: 6455a8a84bdf ("power: supply: max17040: Use regmap i2c")
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> ---
>  drivers/power/supply/max17040_battery.c | 2 ++
>  1 file changed, 2 insertions(+)


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>


Best regards,
Krzysztof