From: Yang Yingliang yangyingliang@huawei.com
commit 2c0ad3f0cc04dec489552a21b80cd6d708bea96d upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/industrialio-buffer.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1311,6 +1311,11 @@ static struct attribute *iio_buffer_wrap 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);