On 26/07/2024 6:20, syzbot wrote:
WARNING: possible recursive locking detected 6.10.0-syzkaller-g933069701c1b #0 Not tainted -------------------------------------------- kworker/1:1H/1247 is trying to acquire lock: ffff888121075948 ((wq_completion)xillyusb){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x6e/0x120 kernel/workqueue.c:3876 but task is already holding lock: ffff888121075948 ((wq_completion)xillyusb){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206
This is caused by xillyusb.c: destroy_workqueue() is (potentially) called from within a work item function, wakeup_all(). So the work item may attempt to destroy the work queue it sits on.
This bug has sneaked through the hardware tests as well as XillyUSB's users for several years, as its scenario is extremely unlikely in real life. It's nevertheless a bug to be fixed -- I'll submit a patch for this.
Thanks, Eli