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 type of index variable to int. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Anton Vasilyev <[email protected]> --- drivers/tty/serial/mxs-auart.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 76aa289652f7..89b34bb09cde 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -1617,7 +1617,7 @@ static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s) static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s) { int *irq = s->gpio_irq; - enum mctrl_gpio_idx i; + int i; int err = 0; for (i = 0; (i < UART_GPIO_MAX) && !err; i++) { @@ -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); -- 2.18.0
