[PATCH 5.15 120/917] iio: core: check return value when calling dev_set_name()

[Greg Kroah-Hartman]

From: Yang Yingliang <yangyingliang@xxxxxxxxxx>

commit fe6f45f6ba22d625a8500cbad0237c60dd3117ee upstream.

I got a null-ptr-deref report when doing fault injection test:

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:strlen+0x0/0x20
Call Trace:
 start_creating+0x199/0x2f0
 debugfs_create_dir+0x25/0x430
 __iio_device_register+0x4da/0x1b40 [industrialio]
 __devm_iio_device_register+0x22/0x80 [industrialio]
 max1027_probe+0x639/0x860 [max1027]
 spi_probe+0x183/0x210
 really_probe+0x285/0xc30

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

Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Fixes: e553f182d55b ("staging: iio: core: Introduce debugfs support...")
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Cc: <Stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20211012063624.3167460-1-yangyingliang@xxxxxxxxxx
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/iio/industrialio-core.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1665,7 +1665,13 @@ struct iio_dev *iio_device_alloc(struct
 		kfree(iio_dev_opaque);
 		return NULL;
 	}
-	dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id);
+
+	if (dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id)) {
+		ida_simple_remove(&iio_ida, iio_dev_opaque->id);
+		kfree(iio_dev_opaque);
+		return NULL;
+	}
+
 	INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
 	INIT_LIST_HEAD(&iio_dev_opaque->ioctl_handlers);