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
