From: Dan Carpenter dan.carpenter@linaro.org

stable inclusion from stable-v4.19.315 commit a98ff250b5af87f92f17bb9725cb21de1931ee57 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4KN CVE: CVE-2023-52756

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v...

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[ 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 Signed-off-by: Wenyu Huang huangwenyu5@huawei.com --- 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 bd7d611d63e9..c6e981035c3f 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -44,8 +44,8 @@ struct pwm_args { };

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

/*