From 2d2c668480278dffcd0167b012d196e30d953b09 Mon Sep 17 00:00:00 2001 From: Ben Dai Date: Sun, 25 Apr 2021 23:09:03 +0800 Subject: [PATCH] genirq/timings: Prevent potential array overflow in __irq_timings_store() commit b9cc7d8a4656a6e815852c27ab50365009cb69c1 upstream. 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: 23aa3b9a6b7d ("genirq/timings: Encapsulate storing function") Signed-off-by: Ben Dai Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210425150903.25456-1-ben.dai9703@gmail.com Signed-off-by: Greg Kroah-Hartman --- kernel/irq/timings.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/irq/timings.c b/kernel/irq/timings.c index 773b6105c4ae..6990490fa67b 100644 --- a/kernel/irq/timings.c +++ b/kernel/irq/timings.c @@ -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.