diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2021-10-05 15:24:49 +0300 |
|---|---|---|
| committer | Bartosz Golaszewski <brgl@bgdev.pl> | 2021-10-06 13:04:04 +0200 |
| commit | 6fda593f3082ef1aa783ac13e89f673fd69a2cb6 (patch) | |
| tree | 045b8bc8e07feb6816358f9e6c35d7542d162935 /drivers/gpio | |
| parent | 55a9968c7e139209a9e93d4ca4321731bea5fc95 (diff) | |
gpio: mockup: Convert to use software nodes
The gpio-mockup driver creates the properties that are shared between
platform and GPIO devices. Because of that, the properties may not
be removed at the proper point of time without provoking a use-after-free
as shown in the following backtrace:
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 103 at lib/refcount.c:28 refcount_warn_saturate+0xd1/0x120
...
Call Trace:
kobject_put+0xdc/0xf0
software_node_notify_remove+0xa8/0xc0
device_del+0x15a/0x3e0
That's why the driver has to manage the lifetime of the software nodes
by itself.
The problem originates from the old device_add_properties() API, but
has been only revealed after the commit bd1e336aa853 ("driver core: platform:
Remove platform_device_add_properties()"). Hence, it's used as a landmark
for backporting.
Fixes: bd1e336aa853 ("driver core: platform: Remove platform_device_add_properties()")
Reported-by: Kent Gibson <warthog618@gmail.com>
Tested-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Bartosz: tweaked local variable placement]
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpio-mockup.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 0a9d746a0fe0..d26bff29157b 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -476,10 +476,19 @@ static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC]; static void gpio_mockup_unregister_pdevs(void) { + struct platform_device *pdev; + struct fwnode_handle *fwnode; int i; - for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) - platform_device_unregister(gpio_mockup_pdevs[i]); + for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) { + pdev = gpio_mockup_pdevs[i]; + if (!pdev) + continue; + + fwnode = dev_fwnode(&pdev->dev); + platform_device_unregister(pdev); + fwnode_remove_software_node(fwnode); + } } static __init char **gpio_mockup_make_line_names(const char *label, @@ -508,6 +517,7 @@ static int __init gpio_mockup_register_chip(int idx) struct property_entry properties[GPIO_MOCKUP_MAX_PROP]; struct platform_device_info pdevinfo; struct platform_device *pdev; + struct fwnode_handle *fwnode; char **line_names = NULL; char chip_label[32]; int prop = 0, base; @@ -536,13 +546,18 @@ static int __init gpio_mockup_register_chip(int idx) "gpio-line-names", line_names, ngpio); } + fwnode = fwnode_create_software_node(properties, NULL); + if (IS_ERR(fwnode)) + return PTR_ERR(fwnode); + pdevinfo.name = "gpio-mockup"; pdevinfo.id = idx; - pdevinfo.properties = properties; + pdevinfo.fwnode = fwnode; pdev = platform_device_register_full(&pdevinfo); kfree_strarray(line_names, ngpio); if (IS_ERR(pdev)) { + fwnode_remove_software_node(fwnode); pr_err("error registering device"); return PTR_ERR(pdev); } |