syzbot

nci: __nci_request: wait_for_completion_interruptible_timeout failed -512
nci: nci_start_poll: failed to set local general bytes
nci: __nci_request: wait_for_completion_interruptible_timeout failed 0
======================================================
WARNING: possible circular locking dependency detected
6.1.55-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor990/3554 is trying to acquire lock:
ffffffff8d9d1d48 (nci_mutex){+.+.}-{3:3}, at: virtual_nci_close+0x13/0x40 drivers/nfc/virtual_ncidev.c:44

but task is already holding lock:
ffff8880176c3350 (&ndev->req_lock){+.+.}-{3:3}, at: nci_close_device+0x106/0x5f0 net/nfc/nci/core.c:560

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&ndev->req_lock){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       nci_request net/nfc/nci/core.c:148 [inline]
       nci_set_local_general_bytes net/nfc/nci/core.c:774 [inline]
       nci_start_poll+0x59f/0xf20 net/nfc/nci/core.c:838
       nfc_start_poll+0x184/0x2f0 net/nfc/core.c:225
       nfc_genl_start_poll+0x1e7/0x350 net/nfc/netlink.c:828
       genl_family_rcv_msg_doit net/netlink/genetlink.c:756 [inline]
       genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
       genl_rcv_msg+0xc1a/0xf70 net/netlink/genetlink.c:850
       netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2495
       genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
       netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
       netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
       netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
       sock_sendmsg_nosec net/socket.c:716 [inline]
       sock_sendmsg net/socket.c:736 [inline]
       ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2482
       ___sys_sendmsg net/socket.c:2536 [inline]
       __sys_sendmsg+0x2a9/0x390 net/socket.c:2565
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #2 (&genl_data->genl_data_mutex){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       nfc_urelease_event_work+0x113/0x2f0 net/nfc/netlink.c:1849
       process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
       worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
       kthread+0x28d/0x320 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

-> #1 (nfc_devlist_mutex){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       nfc_register_device+0x38/0x310 net/nfc/core.c:1116
       nci_register_device+0x7be/0x900 net/nfc/nci/core.c:1256
       virtual_ncidev_open+0x55/0xc0 drivers/nfc/virtual_ncidev.c:146
       misc_open+0x304/0x380 drivers/char/misc.c:143
       chrdev_open+0x54a/0x630 fs/char_dev.c:414
       do_dentry_open+0x7f9/0x10f0 fs/open.c:882
       do_open fs/namei.c:3557 [inline]
       path_openat+0x2644/0x2e60 fs/namei.c:3714
       do_filp_open+0x230/0x480 fs/namei.c:3741
       do_sys_openat2+0x13b/0x500 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __x64_sys_openat+0x243/0x290 fs/open.c:1345
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (nci_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3824
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5048
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       virtual_nci_close+0x13/0x40 drivers/nfc/virtual_ncidev.c:44
       nci_close_device+0x3a8/0x5f0 net/nfc/nci/core.c:592
       nci_unregister_device+0x3c/0x230 net/nfc/nci/core.c:1291
       virtual_ncidev_close+0x55/0x90 drivers/nfc/virtual_ncidev.c:166
       __fput+0x3b7/0x890 fs/file_table.c:320
       task_work_run+0x246/0x300 kernel/task_work.c:179
       exit_task_work include/linux/task_work.h:38 [inline]
       do_exit+0xa73/0x26a0 kernel/exit.c:869
       do_group_exit+0x202/0x2b0 kernel/exit.c:1019
       get_signal+0x16f7/0x17d0 kernel/signal.c:2862
       arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
       exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
       __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
       syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297
       do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  nci_mutex --> &genl_data->genl_data_mutex --> &ndev->req_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ndev->req_lock);
                               lock(&genl_data->genl_data_mutex);
                               lock(&ndev->req_lock);
  lock(nci_mutex);

 *** DEADLOCK ***

1 lock held by syz-executor990/3554:
 #0: ffff8880176c3350 (&ndev->req_lock){+.+.}-{3:3}, at: nci_close_device+0x106/0x5f0 net/nfc/nci/core.c:560

stack backtrace:
CPU: 1 PID: 3554 Comm: syz-executor990 Not tainted 6.1.55-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3824
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5048
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
 virtual_nci_close+0x13/0x40 drivers/nfc/virtual_ncidev.c:44
 nci_close_device+0x3a8/0x5f0 net/nfc/nci/core.c:592
 nci_unregister_device+0x3c/0x230 net/nfc/nci/core.c:1291
 virtual_ncidev_close+0x55/0x90 drivers/nfc/virtual_ncidev.c:166
 __fput+0x3b7/0x890 fs/file_table.c:320
 task_work_run+0x246/0x300 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa73/0x26a0 kernel/exit.c:869
 do_group_exit+0x202/0x2b0 kernel/exit.c:1019
 get_signal+0x16f7/0x17d0 kernel/signal.c:2862
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc2d9170509
Code: Unable to access opcode bytes at 0x7fc2d91704df.
RSP: 002b:00007fc2d910f238 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 0000000000000024 RBX: 00007fc2d91fa378 RCX: 00007fc2d9170509
RDX: 0000000000000000 RSI: 0000000020000440 RDI: 0000000000000004
RBP: 00007fc2d91fa370 R08: 0000000000000003 R09: 00007fc2d910f6c0
R10: 0000000000000008 R11: 0000000000000246 R12: 00007fc2d91c7074
R13: 000000000000006e R14: 00007fff0d90c970 R15: 00007fff0d90ca58
 </TASK>