[PATCH AUTOSEL 6.1 6/6] pwm: Fix double shift bug

Sasha Levin
2023-11-15T03:40:15Z

From: Dan Carpenter <dan.carpenter@linaro.org>

[ Upstream commit d27abbfd4888d79dd24baf50e774631046ac4732 ]

These enums are passed to set/test_bit(). The set/test_bit() functions
take a bit number instead of a shifted value. Passing a shifted value
is a double shift bug like doing BIT(BIT(1)). The double shift bug
doesn't cause a problem here because we are only checking 0 and 1 but
if the value was 5 or above then it can lead to a buffer overflow.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/pwm.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 161e91167b9c0..5e88f1b591832 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -41,8 +41,8 @@ struct pwm_args {
};

enum {
- PWMF_REQUESTED = 1 << 0,
- PWMF_EXPORTED = 1 << 1,
+ PWMF_REQUESTED = 0,
+ PWMF_EXPORTED = 1,
};

/*
--
2.42.0