tree c01504c4f71f0701226566f0ab859e5c9bd56097
parent 30c66fc30ee7a98c4f3adf5fb7e213b61884474f
author Frederic Weisbecker <frederic@kernel.org> 1594994740 +0200
committer Thomas Gleixner <tglx@linutronix.de> 1595015045 +0200

timer: Fix wheel index calculation on last level

When an expiration delta falls into the last level of the wheel, that delta
has be compared against the maximum possible delay and reduced to fit in if
necessary.

However instead of comparing the delta against the maximum, the code
compares the actual expiry against the maximum. Then instead of fixing the
delta to fit in, it sets the maximum delta as the expiry value.

This can result in various undesired outcomes, the worst possible one
being a timer expiring 15 days ahead to fire immediately.

Fixes: 500462a9de65 ("timers: Switch to a non-cascading wheel")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200717140551.29076-2-frederic@kernel.org