Skip to contentSkip to conversation

FAILED: patch "[PATCH] gpio: fix gpio-device list corruption" failed to apply to 5.11-stable tree

PATCH [email protected] 2 participants 3 messages Mar 11, 2021 – Mar 12, 2021

Subsystems (2)
Stable branch GPIO
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 5.11-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From cf25ef6b631c6fc6c0435fc91eba8734cca20511 Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption

Make sure to hold the gpio_lock when removing the gpio device from the gpio_devices list (when dropping the last reference) to avoid corrupting the list when there are concurrent accesses.

Fixes ff2b13592299 ("gpio: make the gpiochip a real device")
Cc [email protected] # 4.6
Reviewed-by Saravana Kannan <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
Signed-off-by Bartosz Golaszewski <[email protected]>
drivers/gpio/gpiolib.c +4 -0
index 6e0572515d02..4253837f870b 100644
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
 static void gpiodevice_release(struct device *dev)
 {
 	struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+	unsigned long flags;
 
+	spin_lock_irqsave(&gpio_lock, flags);
 	list_del(&gdev->list);
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
 	ida_free(&gpio_ida, gdev->id);
 	kfree_const(gdev->label);
 	kfree(gdev->descs);
Reviewed-by Saravana Kannan
#1 lore raw
Quoted 31 lines · Greg Kroah-Hartman

The patch below does not apply to the 5.11-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

------------------ original commit in Linus's tree ------------------

From cf25ef6b631c6fc6c0435fc91eba8734cca20511 Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption

Make sure to hold the gpio_lock when removing the gpio device from the gpio_devices list (when dropping the last reference) to avoid corrupting the list when there are concurrent accesses.

Fixes ff2b13592299 ("gpio: make the gpiochip a real device")
Cc [email protected] # 4.6
Reviewed-by Saravana Kannan <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
Signed-off-by Bartosz Golaszewski <[email protected]>
drivers/gpio/gpiolib.c +0 -0
index 6e0572515d02..4253837f870b 100644
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
 static void gpiodevice_release(struct device *dev)
 {

drivers/gpio/gpiolib.c EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); · line 486

Quoted 10 lines
drivers/gpio/gpiolib.c +4 -0
 	struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+	unsigned long flags;
 
+	spin_lock_irqsave(&gpio_lock, flags);
 	list_del(&gdev->list);
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
 	ida_free(&gpio_ida, gdev->id);
 	kfree_const(gdev->label);
 	kfree(gdev->descs);

Bah, that's because of a6112998ee45 ("gpio: fix NULL-deref-on-deregistration regression") which is strictly only needed in 5.12 even if it could be backported (the commit message might be a bit confusing though).

I should have reversed the order of these two.

Below is a backport to 5.11.

Johan

From 7599320f36bb5273844dfb749861a5361d8aa5b7 Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption

Make sure to hold the gpio_lock when removing the gpio device from the gpio_devices list (when dropping the last reference) to avoid corrupting the list when there are concurrent accesses.

Fixes ff2b13592299 ("gpio: make the gpiochip a real device")
Cc [email protected] # 4.6
Reviewed-by Saravana Kannan <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
Signed-off-by Bartosz Golaszewski <[email protected]>
[ johan: adjust context to 5.11 ]
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/gpio/gpiolib.c | 4 ++++
 1 file changed, 4 insertions(+)
drivers/gpio/gpiolib.c +4 -0
index adf55db080d8..0069b115928c 100644
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
 static void gpiodevice_release(struct device *dev)
 {
 	struct gpio_device *gdev = dev_get_drvdata(dev);
+	unsigned long flags;
 
+	spin_lock_irqsave(&gpio_lock, flags);
 	list_del(&gdev->list);
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
 	ida_free(&gpio_ida, gdev->id);
 	kfree_const(gdev->label);
 	kfree(gdev->descs);
Signature · 1 line
2.26.2
author maintainer
#2 lore raw
Quoted 48 lines · Johan Hovold
Quoted 31 lines · Greg Kroah-Hartman

The patch below does not apply to the 5.11-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

------------------ original commit in Linus's tree ------------------

From cf25ef6b631c6fc6c0435fc91eba8734cca20511 Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption

Make sure to hold the gpio_lock when removing the gpio device from the gpio_devices list (when dropping the last reference) to avoid corrupting the list when there are concurrent accesses.

Fixes ff2b13592299 ("gpio: make the gpiochip a real device")
Cc [email protected] # 4.6
Reviewed-by Saravana Kannan <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
Signed-off-by Bartosz Golaszewski <[email protected]>
drivers/gpio/gpiolib.c +0 -0
index 6e0572515d02..4253837f870b 100644
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
 static void gpiodevice_release(struct device *dev)
 {

drivers/gpio/gpiolib.c EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); · line 486

Quoted 10 lines
drivers/gpio/gpiolib.c +4 -0
 	struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+	unsigned long flags;
 
+	spin_lock_irqsave(&gpio_lock, flags);
 	list_del(&gdev->list);
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
 	ida_free(&gpio_ida, gdev->id);
 	kfree_const(gdev->label);
 	kfree(gdev->descs);

Bah, that's because of a6112998ee45 ("gpio: fix NULL-deref-on-deregistration regression") which is strictly only needed in 5.12 even if it could be backported (the commit message might be a bit confusing though).

Quoted 3 lines

I should have reversed the order of these two.

Below is a backport to 5.11.

Thanks for the backport, also added to 5.10.y

greg k-h