Hello, syzbot found the following issue on: HEAD commit: 519d81956ee2 Linux 5.15-rc6 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16787178b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=1f7f46d98a0da80e dashboard link: https://syzkaller.appspot.com/bug?extid=f2725165900304ec97b6 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f2725165900304ec97b6@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: trying to register non-static key. The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator. CPU: 1 PID: 24628 Comm: syz-executor.5 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 assign_lock_key kernel/locking/lockdep.c:939 [inline] register_lock_class+0xf79/0x10c0 kernel/locking/lockdep.c:1251 __lock_acquire+0x105/0x54a0 kernel/locking/lockdep.c:4894 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] hci_uart_tty_receive+0xc4/0x710 drivers/bluetooth/hci_ldisc.c:603 tiocsti drivers/tty/tty_io.c:2310 [inline] tty_ioctl+0x909/0x1670 drivers/tty/tty_io.c:2719 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7ff49c1bfa39 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff4996b1188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff49c2c3260 RCX: 00007ff49c1bfa39 RDX: 0000000020000000 RSI: 0000000000005412 RDI: 0000000000000005 RBP: 00007ff49c219c5f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffa845426f R14: 00007ff4996b1300 R15: 0000000000022000 --- 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.