⚪ hwmon: (corsair-psu) Stop device IO before calling hid_hw_stop (Linux Linux)

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (corsair-psu) Stop device IO before calling hid_hw_stop hid_hw_stop() does not stop the device IO. This results in a race condition between hid_input_report() and the point immediately following the execution of hid_device_io_start() within corsairpsu_probe(). If the probe operation fails after "io start" has been initiated, this race condition will result in a uaf vulnerability [1]. CPU0 CPU1 ==== ==== corsairpsu_probe() hid_device_io_start() ... unlock driver_input_lock hid_hw_stop() kfree(hidraw) __hid_input_report() ... acquire driver_input_lock hid_report_raw_event() hidraw_report_event() ... access hidraw's list_lock // trigger uaf Consequently, when corsairpsu_probe() fails and hid_hw_stop() needs to be executed, the io_started flag is first cleared while holding the driver_input_lock to prevent potential race conditions involving input reports. [1] BUG: KASAN: slab-use-after-free in rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 Call Trace: hidraw_report_event+0x5d/0x3a0 drivers/hid/hidraw.c:577 hid_report_raw_event+0x311/0x1730 drivers/hid/hid-core.c:2076 __hid_input_report drivers/hid/hid-core.c:2152 [inline] hid_input_report+0x44e/0x580 drivers/hid/hid-core.c:2174 hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286 __usb_hcd_giveback_urb+0x3b3/0x5e0 drivers/usb/core/hcd.c:1657 dummy_timer+0x8a9/0x47d0 drivers/usb/gadget/udc/dummy_hcd.c:2005 Allocated by task 10: hidraw_connect+0x57/0x430 drivers/hid/hidraw.c:606 hid_connect+0x5bf/0x19d0 drivers/hid/hid-core.c:2277 hid_hw_start+0xa8/0x120 drivers/hid/hid-core.c:2387 corsairpsu_probe+0xd9/0x3c0 drivers/hwmon/corsair-psu.c:782 Freed by task 10: hidraw_disconnect+0x4f/0x60 drivers/hid/hidraw.c:662 hid_disconnect drivers/hid/hid-core.c:2362 [inline] hid_hw_stop+0x101/0x1e0 drivers/hid/hid-core.c:2407 corsairpsu_probe+0x327/0x3c0 drivers/hwmon/corsair-psu.c:826 Fix the problem by calling hid_device_io_stop() before calling hid_hw_stop(). [groeck: Updated subject and description; call hid_device_io_stop() only if IO has been started]