From: Anton Vasilyev <vasilyev@xxxxxxxxx> [ Upstream commit 5963e8a3122471cadfe0eba41c4ceaeaa5c8bb4d ] 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> Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 673c8fd7e34f6..e83750831f15e 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -1638,8 +1638,9 @@ 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); -- 2.20.1
