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authorYang Yingliang <yangyingliang@huawei.com>2022-12-02 11:02:37 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-12-02 17:48:59 +0100
commit11fa7fefe3d8fac7da56bc9aa3dd5fb3081ca797 (patch)
treef073ff48f5efe100bc175a13c932c4590966dc3a
parent728ac3389296caf68638628c987aeae6c8851e2d (diff)
chardev: fix error handling in cdev_device_add()
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>
-rw-r--r--fs/char_dev.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/char_dev.c b/fs/char_dev.c
index 340e4543b24a..13deb45f1ec6 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -554,7 +554,7 @@ 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;