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

iio: buffer: check return value of kstrdup_const()

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-next 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 also be merged in the next major kernel release during the merge window.

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

From 2c0ad3f0cc04dec489552a21b80cd6d708bea96d Mon Sep 17 00:00:00 2001

From: Yang Yingliang yangyingliang@huawei.com Date: Wed, 13 Oct 2021 12:04:38 +0800 Subject: iio: buffer: check return value of kstrdup_const()

Check return value of kstrdup_const() in iio_buffer_wrap_attr(), or it will cause null-ptr-deref in kernfs_name_hash() when calling device_add() as follows:

BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:strlen+0x0/0x20 Call Trace: kernfs_name_hash+0x22/0x110 kernfs_find_ns+0x11d/0x390 kernfs_remove_by_name_ns+0x3b/0xb0 remove_files.isra.1+0x7b/0x190 internal_create_group+0x7f1/0xbb0 internal_create_groups+0xa3/0x150 device_add+0x8f0/0x2020 cdev_device_add+0xc3/0x160 __iio_device_register+0x1427/0x1b40 [industrialio] __devm_iio_device_register+0x22/0x80 [industrialio] adjd_s311_probe+0x195/0x200 [adjd_s311] i2c_device_probe+0xa07/0xbb0

Reported-by: Hulk Robot hulkci@huawei.com Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") Signed-off-by: Yang Yingliang yangyingliang@huawei.com Link: https://lore.kernel.org/r/20211013040438.1689277-1-yangyingliang@huawei.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- drivers/iio/industrialio-buffer.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index a95cc2da56be..55802da1deee 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1312,6 +1312,11 @@ static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer, iio_attr->buffer = buffer; memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr)); iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL); + if (!iio_attr->dev_attr.attr.name) { + kfree(iio_attr); + return NULL; + } + sysfs_attr_init(&iio_attr->dev_attr.attr);

list_add(&iio_attr->l, &buffer->buffer_attr_list);