diff mbox series

[5.4,48/62] genirq/timings: Prevent potential array overflow in __irq_timings_store()

Message ID 20210816125429.857450393@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH Aug. 16, 2021, 1:02 p.m. UTC 
From: Ben Dai <ben.dai@unisoc.com>

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 <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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 kernel/irq/timings.c |    5 +++++
 1 file changed, 5 insertions(+)
diff mbox series

Patch

--- a/kernel/irq/timings.c
+++ b/kernel/irq/timings.c
@@ -453,6 +453,11 @@  static __always_inline void __irq_timing
 	 */
 	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.