[PATCH 5.14 153/849] iio: core: check return value when calling dev_set_name()

Greg Kroah-Hartman
2021-11-15T21:54:42Z

From: Yang Yingliang <yangyingliang@huawei.com>

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@huawei.com>
Fixes: e553f182d55b ("staging: iio: core: Introduce debugfs support...")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211012063624.3167460-1-yangyingliang@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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
@@ -1662,7 +1662,13 @@ 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);