Affected: Linux, Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

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

usb: gadget: f_fs: Remove WARN_ON in functionfs_bind

This commit addresses an issue related to below kernel panic where panic_on_warn is enabled. It is caused by the unnecessary use of WARN_ON in functionsfs_bind, which easily leads to the following scenarios.

1.adb_write in adbd 2. UDC write via configfs ================= =====================

->usb_ffs_open_thread() ->UDC write ->open_functionfs() ->configfs_write_iter() ->adb_open() ->gadget_dev_desc_UDC_store() ->adb_write() ->usb_gadget_register_driver_owner ->driver_register() ->StartMonitor() ->bus_add_driver() ->adb_read() ->gadget_bind_driver() <times-out without BIND event> ->configfs_composite_bind() ->usb_add_function() ->open_functionfs() ->ffs_func_bind() ->adb_open() ->functionfs_bind() <ffs->state !=FFS_ACTIVE>

The adb_open, adb_read, and adb_write operations are invoked from the daemon, but trying to bind the function is a process that is invoked by UDC write through configfs, which opens up the possibility of a race condition between the two paths. In this race scenario, the kernel panic occurs due to the WARN…