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

[Bart Van Assche]

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@xxxxxxxxx>
> > Cc: Nick Dyer <nick@xxxxxxxxxxxxx>
> > Cc: linux-input@xxxxxxxxxxxxxxx
> > Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
> > Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> > ---
> >   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.