From: Yang Yingliang Date: Wed, 13 Oct 2021 03:05:32 +0000 (+0800) Subject: iio: core: fix double free in iio_device_unregister_sysfs() X-Git-Tag: v5.16-rc1~119^2~16^2~2 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=19833c40d0415d6fe4340b5b9c46239abbf718f6;p=tomoyo%2Ftomoyo-test1.git iio: core: fix double free in iio_device_unregister_sysfs() I got the double free report: BUG: KASAN: double-free or invalid-free in kfree+0xce/0x390 iio_device_unregister_sysfs+0x108/0x13b [industrialio] iio_dev_release+0x9e/0x10e [industrialio] device_release+0xa5/0x240 If __iio_device_register() fails, iio_dev_opaque->groups will be freed in error path in iio_device_unregister_sysfs(), then iio_dev_release() will call iio_device_unregister_sysfs() again, it causes double free. Set iio_dev_opaque->groups to NULL when it's freed to fix this double free. Not this is a local work around for a more general mess around life time management that will get cleaned up and should make this handling unnecesarry. Fixes: 32f171724e5c ("iio: core: rework iio device group creation") Reported-by: Hulk Robot Reviewed-by: Alexandru Ardelean Signed-off-by: Yang Yingliang Link: https://lore.kernel.org/r/20211013030532.956133-1-yangyingliang@huawei.com Cc: Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 48fda6a79076..3e1e86d987cc 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1600,6 +1600,7 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev) kfree(iio_dev_opaque->chan_attr_group.attrs); iio_dev_opaque->chan_attr_group.attrs = NULL; kfree(iio_dev_opaque->groups); + iio_dev_opaque->groups = NULL; } static void iio_dev_release(struct device *device)