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Patch "Input: matrix_keypad - fix race when disabling interrupts" has been added to the 3.18-stable tree

PATCH [email protected] 1 participant 1 message Mar 12, 2018

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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 3.18-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-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From ea4f7bd2aca9f68470e9aac0fc9432fd180b1fe7 Mon Sep 17 00:00:00 2001

From: Zhang Bo <[email protected]>
Date: Mon, 5 Feb 2018 14:56:21 -0800
Subject: Input: matrix_keypad - fix race when disabling interrupts

From: Zhang Bo <[email protected]>

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.

---
 drivers/input/keyboard/matrix_keypad.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
drivers/input/keyboard/matrix_keypad.c +3 -1
@@ -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 [email protected] are

queue-3.18/input-matrix_keypad-fix-race-when-disabling-interrupts.patch