Hello, syzbot found the following issue on: HEAD commit: b446a2dae984 Merge tag 'linux_kselftest-fixes-6.11-rc3' of.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=1253e123980000 kernel config: https://syzkaller.appspot.com/x/.config?x=e8a2eef9745ade09 dashboard link: https://syzkaller.appspot.com/bug?extid=e528c9aad0fb5383ec83 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a6bd23980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10b175e3980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/dfb1bb3422ba/disk-b446a2da.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/af839611c6d9/vmlinux-b446a2da.xz kernel image: https://storage.googleapis.com/syzbot-assets/b99bed56482e/bzImage-b446a2da.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e528c9aad0fb5383ec83@xxxxxxxxxxxxxxxxxxxxxxxxx ============================================ WARNING: possible recursive locking detected 6.11.0-rc2-syzkaller-00004-gb446a2dae984 #0 Not tainted -------------------------------------------- kworker/0:1H/58 is trying to acquire lock: ffff88802c60a148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: touch_wq_lockdep_map kernel/workqueue.c:3876 [inline] ffff88802c60a148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: __flush_workqueue+0x1b0/0x1710 kernel/workqueue.c:3918 but task is already holding lock: ffff88802c60a148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] ffff88802c60a148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((wq_completion)xillyusb); lock((wq_completion)xillyusb); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by kworker/0:1H/58: #0: ffff88802c60a148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88802c60a148 ((wq_completion)xillyusb){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc9000133fd00 ((work_completion)(&xdev->wakeup_workitem)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc9000133fd00 ((work_completion)(&xdev->wakeup_workitem)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 stack backtrace: CPU: 0 UID: 0 PID: 58 Comm: kworker/0:1H Not tainted 6.11.0-rc2-syzkaller-00004-gb446a2dae984 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: xillyusb wakeup_all Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 touch_wq_lockdep_map kernel/workqueue.c:3876 [inline] __flush_workqueue+0x1c9/0x1710 kernel/workqueue.c:3918 drain_workqueue+0xc9/0x3a0 kernel/workqueue.c:4082 destroy_workqueue+0xba/0xc40 kernel/workqueue.c:5781 cleanup_dev drivers/char/xillybus/xillyusb.c:558 [inline] kref_put+0x104/0x180 include/linux/kref.h:65 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
