| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 482/639] PM: sleep: Fix possible overflow in pm_system_cancel_wakeup() | Date | Fri, 24 Jan 2020 10:30:52 +0100 |
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[ Upstream commit 2933954b71f10d392764f95eec0f0aa2d103054b ]
It is not actually guaranteed that pm_abort_suspend will be nonzero when pm_system_cancel_wakeup() is called which may lead to subtle issues, so make it use atomic_dec_if_positive() instead of atomic_dec() for the safety sake.
Fixes: 33e4f80ee69b ("ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/base/power/wakeup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 7c84f64c74f77..2dfa2e0487451 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -875,7 +875,7 @@ EXPORT_SYMBOL_GPL(pm_system_wakeup); void pm_system_cancel_wakeup(void) { - atomic_dec(&pm_abort_suspend); + atomic_dec_if_positive(&pm_abort_suspend); } void pm_wakeup_clear(bool reset) -- 2.20.1
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