patch "iio: core: check return value when calling dev_set_name()" added to char-misc-testing

patch "iio: core: check return value when calling dev_set_name()" added to char-misc-testing

[gregkh]

This is a note to let you know that I've just added the patch titled

    iio: core: check return value when calling dev_set_name()

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the char-misc-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


From fe6f45f6ba22d625a8500cbad0237c60dd3117ee Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang@huawei.com>
Date: Tue, 12 Oct 2021 14:36:24 +0800
Subject: iio: core: check return value when calling dev_set_name()

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>
---
 drivers/iio/industrialio-core.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 2dbb37e09b8c..48fda6a79076 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1664,7 +1664,13 @@ struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
 		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);
 
-- 
2.33.1