From: Yang Yingliang yangyingliang@huawei.com
[ Upstream commit 11fa7fefe3d8fac7da56bc9aa3dd5fb3081ca797 ]
While doing fault injection test, I got the following report:
------------[ cut here ]------------ kobject: '(null)' (0000000039956980): is not initialized, yet kobject_put() is being called. WARNING: CPU: 3 PID: 6306 at kobject_put+0x23d/0x4e0 CPU: 3 PID: 6306 Comm: 283 Tainted: G W 6.1.0-rc2-00005-g307c1086d7c9 #1253 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:kobject_put+0x23d/0x4e0 Call Trace: <TASK> cdev_device_add+0x15e/0x1b0 __iio_device_register+0x13b4/0x1af0 [industrialio] __devm_iio_device_register+0x22/0x90 [industrialio] max517_probe+0x3d8/0x6b4 [max517] i2c_device_probe+0xa81/0xc00
When device_add() is injected fault and returns error, if dev->devt is not set, cdev_add() is not called, cdev_del() is not needed. Fix this by checking dev->devt in error path.
Fixes: 233ed09d7fda ("chardev: add helper function to register char devs with a struct device") Signed-off-by: Yang Yingliang yangyingliang@huawei.com Link: https://lore.kernel.org/r/20221202030237.520280-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/char_dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/char_dev.c b/fs/char_dev.c index 1bbb966c0783..9f79fd345e79 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -528,7 +528,7 @@ int cdev_device_add(struct cdev *cdev, struct device *dev) }
rc = device_add(dev); - if (rc) + if (rc && dev->devt) cdev_del(cdev);
return rc;