On Tue, Aug 07, 2018 at 01:59:05PM +0300, Anton Vasilyev wrote: > On the error path of mxs_auart_request_gpio_irq() is performed > backward iterating with index i of enum type. Underline enum type > may be unsigned char. In this case check (--i >= 0) will be always > true and error handling goes into infinite loop. > > The patch changes the check so that it is valid for signed and unsigned > types. > > Found by Linux Driver Verification project (linuxtesting.org). > > Signed-off-by: Anton Vasilyev <vasilyev@xxxxxxxxx> > --- > v2: mistype in patch as result of combination of different fixes. > Change comment and leave enum type. > --- > drivers/tty/serial/mxs-auart.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c > index 76aa289652f7..27235a526cce 100644 > --- a/drivers/tty/serial/mxs-auart.c > +++ b/drivers/tty/serial/mxs-auart.c > @@ -1634,8 +1634,9 @@ static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s) > > /* > * If something went wrong, rollback. > + * Be careful: i may be unsigned. > */ > - while (err && (--i >= 0)) > + while (err && (i-- > 0)) > if (irq[i] >= 0) > free_irq(irq[i], s); I wouldn't have added the comment, but the code change is correct. Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> Thanks Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
