[PATCH 5.17 208/219] i2c: dev: check return value when calling dev_set_name()

Greg Kroah-Hartman
2022-04-18T12:37:34Z

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

commit 993eb48fa199b5f476df8204e652eff63dd19361 upstream.

If dev_set_name() fails, the dev_name() is null, check the return
value of dev_set_name() to avoid the null-ptr-deref.

Fixes: 1413ef638aba ("i2c: dev: Fix the race between the release of i2c_dev and cdev")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/i2c/i2c-dev.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -668,16 +668,21 @@ static int i2cdev_attach_adapter(struct
i2c_dev->dev.class = i2c_dev_class;
i2c_dev->dev.parent = &adap->dev;
i2c_dev->dev.release = i2cdev_dev_release;
- dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr);
+
+ res = dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr);
+ if (res)
+ goto err_put_i2c_dev;

res = cdev_device_add(&i2c_dev->cdev, &i2c_dev->dev);
- if (res) {
- put_i2c_dev(i2c_dev, false);
- return res;
- }
+ if (res)
+ goto err_put_i2c_dev;

pr_debug("adapter [%s] registered as minor %d\n", adap->name, adap->nr);
return 0;
+
+err_put_i2c_dev:
+ put_i2c_dev(i2c_dev, false);
+ return res;
}

static int i2cdev_detach_adapter(struct device *dev, void *dummy)