iio: imu: adis16400: fix unprotected debugfs reads

Overview

In the Linux kernel, the following vulnerability has been resolved:

iio: imu: adis16400: fix unprotected debugfs reads

adis16400_serial_number_fops is open coded and never calls debugfs_file_get(), so debugfs_remove_recursive() does not wait for a read in progress and unbind frees the iio_dev underneath it.

Commit ae1d37a9bb4b ("iio: imu: adis16400: use DEFINE_DEBUGFS_ATTRIBUTE instead of DEFINE_SIMPLE_ATTRIBUTE") converted product_id and flash_count to DEFINE_DEBUGFS_ATTRIBUTE, which protects itself, but moved all three files to debugfs_create_file_unsafe().

serial_number prints three registers as "%.4x-%.4x-%.4x" and DEFINE_DEBUGFS_ATTRIBUTE() formats a single u64, so it cannot be converted without changing what the file returns. adis16475 and adis16550 already use debugfs_create_file() for their open coded files. Use it here too.

Affected

• Linux >= ae1d37a9bb4bd8d9091a40d153143e99b115ee37 < e9b4c00f775a915b759b08bfe2c5e806a8301a59
• Linux >= ae1d37a9bb4bd8d9091a40d153143e99b115ee37 < 50e8d70ba0743f88afd7e49f9cebd1841ee677f5
• Linux >= ae1d37a9bb4bd8d9091a40d153143e99b115ee37 < f501302ebb9e1504162351b951fe3ae331c852ab
• Linux >= ae1d37a9bb4bd8d9091a40d153143e99b115ee37 < d94787287a113a1326211647d5e0deed1e9de105
• Linux 5.8

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.