Patch "Input: matrix_keypad - fix race when disabling interrupts" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    Input: matrix_keypad - fix race when disabling interrupts

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     input-matrix_keypad-fix-race-when-disabling-interrupts.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From ea4f7bd2aca9f68470e9aac0fc9432fd180b1fe7 Mon Sep 17 00:00:00 2001
From: Zhang Bo <zbsdta@126.com>
Date: Mon, 5 Feb 2018 14:56:21 -0800
Subject: Input: matrix_keypad - fix race when disabling interrupts

From: Zhang Bo <zbsdta@126.com>

commit ea4f7bd2aca9f68470e9aac0fc9432fd180b1fe7 upstream.

If matrix_keypad_stop() is executing and the keypad interrupt is triggered,
disable_row_irqs() may be called by both matrix_keypad_interrupt() and
matrix_keypad_stop() at the same time, causing interrupts to be disabled
twice and the keypad being "stuck" after resuming.

Take lock when setting keypad->stopped to ensure that ISR will not race
with matrix_keypad_stop() disabling interrupts.

Signed-off-by: Zhang Bo <zbsdta@126.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/input/keyboard/matrix_keypad.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/input/keyboard/matrix_keypad.c
+++ b/drivers/input/keyboard/matrix_keypad.c
@@ -216,8 +216,10 @@ static void matrix_keypad_stop(struct in
 {
 	struct matrix_keypad *keypad = input_get_drvdata(dev);
 
+	spin_lock_irq(&keypad->lock);
 	keypad->stopped = true;
-	mb();
+	spin_unlock_irq(&keypad->lock);
+
 	flush_work(&keypad->work.work);
 	/*
 	 * matrix_keypad_scan() will leave IRQs enabled;


Patches currently in stable-queue which might be from zbsdta@126.com are

queue-4.4/input-matrix_keypad-fix-race-when-disabling-interrupts.patch