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-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 2c0ad3f0cc04dec489552a21b80cd6d708bea96d Mon Sep 17 00:00:00 2001 From: Yang Yingliang <yangyingliang@xxxxxxxxxx> 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@xxxxxxxxxx> Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211013040438.1689277-1-yangyingliang@xxxxxxxxxx Cc: <Stable@xxxxxxxxxxxxxxx> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> --- 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); -- 2.33.1