Re: [PATCH 15/62] Input: synaptics-rmi4 - fix a locking bug in an error path

[Bart Van Assche <bart.vanassche@gmail.com>]

On 2/23/26 1:58 PM, Dmitry Torokhov wrote:
> Hi Bart,
> 
> On Mon, Feb 23, 2026 at 01:50:30PM -0800, Bart Van Assche wrote:
>> Lock f54->data_mutex before the first 'goto error' statement since
>> jumping to the 'error' label causes that mutex to be unlocked.
>>
>> This bug has been detected by the Clang thread-safety checker.
>>
>> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
>> Cc: Nick Dyer <nick@shmanahar.org>
>> Cc: linux-input@vger.kernel.org
>> Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
>> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
>> ---
>>   drivers/input/rmi4/rmi_f54.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
>> index ac4041a69fcd..fd57ebb1cb50 100644
>> --- a/drivers/input/rmi4/rmi_f54.c
>> +++ b/drivers/input/rmi4/rmi_f54.c
>> @@ -539,6 +539,9 @@ static void rmi_f54_work(struct work_struct *work)
>>   	int i;
>>   
>>   	report_size = rmi_f54_get_report_size(f54);
>> +
>> +	mutex_lock(&f54->data_mutex);
>> +
> 
> Thank you for the patch. Do you mind if I move mutex_lock() above the
> call to rmi_f54_get_report_size()? It does not extend critical section
> by much, and I think logically makes more sense.

That sounds good to me. Please keep in mind that I'm not familiar with
the rmi4 driver.

Thanks,

Bart.