Re: [PATCH 2/2] gpio: fix gpio-device list corruption
From: Saravana Kannan
Date: Fri Feb 26 2021 - 16:00:37 EST
On Fri, Feb 26, 2021 at 6:55 AM Johan Hovold <johan@xxxxxxxxxx> wrote:
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Make sure to hold the gpio_lock when removing the gpio device from the
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gpio_devices list (when dropping the last reference) to avoid corrupting
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the list when there are concurrent accesses.
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Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
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Cc: stable@xxxxxxxxxxxxxxx # 4.6
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Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
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---
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drivers/gpio/gpiolib.c | 4 ++++
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1 file changed, 4 insertions(+)
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diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
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index e1016bc8cf14..42bdc55a15f9 100644
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--- a/drivers/gpio/gpiolib.c
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+++ b/drivers/gpio/gpiolib.c
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@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
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static void gpiodevice_release(struct device *dev)
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{
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struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
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+ unsigned long flags;
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+ spin_lock_irqsave(&gpio_lock, flags);
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list_del(&gdev->list);
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+ spin_unlock_irqrestore(&gpio_lock, flags);
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+
Reviewed-by: Saravana Kannan <saravanak@xxxxxxxxxx>
-Saravana
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ida_free(&gpio_ida, gdev->id);
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kfree_const(gdev->label);
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kfree(gdev->descs);
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--
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2.26.2
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