The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
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: [PATCH] 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
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);