Re: [PATCH v3] i2c: i801: Avoid potential double call to gpiod_remove_lookup_table

[Heiner Kallweit <hkallweit1@gmail.com>]

On 05.03.2024 00:04, Andi Shyti wrote:
> Hi Heiner,
> 
> On Mon, Mar 04, 2024 at 09:31:06PM +0100, Heiner Kallweit wrote:
>> If registering the platform device fails, the lookup table is
>> removed in the error path. On module removal we would try to
>> remove the lookup table again. Fix this by setting priv->lookup
>> only if registering the platform device was successful.
>> In addition free the memory allocated for the lookup table in
>> the error path.
>>
>> Fixes: d308dfbf62ef ("i2c: mux/i801: Switch to use descriptor passing")
>> Cc: stable@vger.kernel.org
>> Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>> ---
>> v2:
>> - cc stable
>> - free memory allocated for the lookup table
>> v3:
>> - cc'ed Linus
> 
> this patch is a resend...
> 
Right, it's effectively a resend.

>> ---
>>  drivers/i2c/busses/i2c-i801.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
>> index 291c609d1..9c624f31c 100644
>> --- a/drivers/i2c/busses/i2c-i801.c
>> +++ b/drivers/i2c/busses/i2c-i801.c
>> @@ -1428,7 +1428,6 @@ static void i801_add_mux(struct i801_priv *priv)
>>  		lookup->table[i] = GPIO_LOOKUP(mux_config->gpio_chip,
>>  					       mux_config->gpios[i], "mux", 0);
>>  	gpiod_add_lookup_table(lookup);
>> -	priv->lookup = lookup;
> 
> if I miss something obvious in my reviews, please let me know...
> I spend most of my time reviewing patches and it happens quite
> often :-)
> 
> Andi
> 
>>  	/*
>>  	 * Register the mux device, we use PLATFORM_DEVID_NONE here
>> @@ -1442,7 +1441,10 @@ static void i801_add_mux(struct i801_priv *priv)
>>  				sizeof(struct i2c_mux_gpio_platform_data));
>>  	if (IS_ERR(priv->mux_pdev)) {
>>  		gpiod_remove_lookup_table(lookup);
>> +		devm_kfree(dev, lookup);
>>  		dev_err(dev, "Failed to register i2c-mux-gpio device\n");
>> +	} else {
>> +		priv->lookup = lookup;
>>  	}
>>  }
>>  
>> -- 
>> 2.44.0
>>