genirq/timings: Prevent potential array overflow in __irq_timings_store()

When the interrupt interval is greater than 2 ^ PREDICTION_BUFFER_SIZE *
PREDICTION_FACTOR us and less than 1s, the calculated index will be greater
than the length of irqs->ema_time[]. Check the calculated index before
using it to prevent array overflow.

Fixes: 23aa3b9a6b ("genirq/timings: Encapsulate storing function")
Signed-off-by: Ben Dai <ben.dai@unisoc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210425150903.25456-1-ben.dai9703@gmail.com
This commit is contained in:
Ben Dai 2021-04-25 23:09:03 +08:00 committed by Thomas Gleixner
parent ff363f480e
commit b9cc7d8a46
1 changed files with 5 additions and 0 deletions

View File

@ -453,6 +453,11 @@ static __always_inline void __irq_timings_store(int irq, struct irqt_stat *irqs,
*/
index = irq_timings_interval_index(interval);
if (index > PREDICTION_BUFFER_SIZE - 1) {
irqs->count = 0;
return;
}
/*
* Store the index as an element of the pattern in another
* circular array.