====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc7-syzkaller-00101-g01f856ae6d0c #0 Not tainted ------------------------------------------------------ syz-executor.3/20666 is trying to acquire lock: ffff88808bc92350 (&ndev->req_lock){+.+.}-{3:3}, at: nci_request net/nfc/nci/core.c:148 [inline] ffff88808bc92350 (&ndev->req_lock){+.+.}-{3:3}, at: nci_set_local_general_bytes net/nfc/nci/core.c:774 [inline] ffff88808bc92350 (&ndev->req_lock){+.+.}-{3:3}, at: nci_start_poll+0x57a/0xef0 net/nfc/nci/core.c:838 but task is already holding lock: ffff88808bc96508 (&genl_data->genl_data_mutex){+.+.}-{3:3}, at: nfc_genl_start_poll+0x1d2/0x340 net/nfc/netlink.c:826 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&genl_data->genl_data_mutex){+.+.}-{3:3}: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668 __mutex_lock_common+0x1de/0x26c0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 nfc_urelease_event_work+0x10a/0x300 net/nfc/netlink.c:1811 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 -> #2 (nfc_devlist_mutex){+.+.}-{3:3}: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668 __mutex_lock_common+0x1de/0x26c0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 nfc_register_device+0x33/0x320 net/nfc/core.c:1116 nci_register_device+0x7c7/0x900 net/nfc/nci/core.c:1256 virtual_ncidev_open+0x55/0xc0 drivers/nfc/virtual_ncidev.c:146 misc_open+0x346/0x3c0 drivers/char/misc.c:143 chrdev_open+0x5fb/0x680 fs/char_dev.c:414 do_dentry_open+0x85f/0x11b0 fs/open.c:882 do_open fs/namei.c:3557 [inline] path_openat+0x260e/0x2e00 fs/namei.c:3714 do_filp_open+0x275/0x500 fs/namei.c:3741 do_sys_openat2+0x13b/0x500 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (nci_mutex){+.+.}-{3:3}: lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668 __mutex_lock_common+0x1de/0x26c0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 virtual_nci_close+0x13/0x40 drivers/nfc/virtual_ncidev.c:44 nci_open_device+0x918/0xd00 net/nfc/nci/core.c:544 nfc_dev_up+0x17d/0x320 net/nfc/core.c:118 nfc_genl_dev_up+0x7f/0xc0 net/nfc/netlink.c:770 genl_family_rcv_msg_doit net/netlink/genetlink.c:756 [inline] genl_family_rcv_msg net/netlink/genetlink.c:833 [inline] genl_rcv_msg+0xc02/0xf60 net/netlink/genetlink.c:850 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2540 genl_rcv+0x24/0x40 net/netlink/genetlink.c:861 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7e7/0x9c0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x9b3/0xcd0 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x597/0x8e0 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x28e/0x390 net/socket.c:2565 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&ndev->req_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain+0x184a/0x6470 kernel/locking/lockdep.c:3831 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668 __mutex_lock_common+0x1de/0x26c0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 nci_request net/nfc/nci/core.c:148 [inline] nci_set_local_general_bytes net/nfc/nci/core.c:774 [inline] nci_start_poll+0x57a/0xef0 net/nfc/nci/core.c:838 nfc_start_poll+0x185/0x2f0 net/nfc/core.c:225 nfc_genl_start_poll+0x1df/0x340 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+0xc02/0xf60 net/netlink/genetlink.c:850 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2540 genl_rcv+0x24/0x40 net/netlink/genetlink.c:861 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7e7/0x9c0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x9b3/0xcd0 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x597/0x8e0 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x28e/0x390 net/socket.c:2565 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &ndev->req_lock --> nfc_devlist_mutex --> &genl_data->genl_data_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&genl_data->genl_data_mutex); lock(nfc_devlist_mutex); lock(&genl_data->genl_data_mutex); lock(&ndev->req_lock); *** DEADLOCK *** 4 locks held by syz-executor.3/20666: #0: ffffffff8e4cac10 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffffffff8e4caac8 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8e4caac8 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x123/0xf60 net/netlink/genetlink.c:848 #2: ffff88808bc96508 (&genl_data->genl_data_mutex){+.+.}-{3:3}, at: nfc_genl_start_poll+0x1d2/0x340 net/nfc/netlink.c:826 #3: ffff88808bc96100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff88808bc96100 (&dev->mutex){....}-{3:3}, at: nfc_start_poll+0x61/0x2f0 net/nfc/core.c:208 stack backtrace: CPU: 1 PID: 20666 Comm: syz-executor.3 Not tainted 6.1.0-rc7-syzkaller-00101-g01f856ae6d0c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2f9/0x3b0 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain+0x184a/0x6470 kernel/locking/lockdep.c:3831 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668 __mutex_lock_common+0x1de/0x26c0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 nci_request net/nfc/nci/core.c:148 [inline] nci_set_local_general_bytes net/nfc/nci/core.c:774 [inline] nci_start_poll+0x57a/0xef0 net/nfc/nci/core.c:838 nfc_start_poll+0x185/0x2f0 net/nfc/core.c:225 nfc_genl_start_poll+0x1df/0x340 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+0xc02/0xf60 net/netlink/genetlink.c:850 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2540 genl_rcv+0x24/0x40 net/netlink/genetlink.c:861 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7e7/0x9c0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x9b3/0xcd0 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x597/0x8e0 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x28e/0x390 net/socket.c:2565 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f346be8c0d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f346cc82168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f346bfac050 RCX: 00007f346be8c0d9 RDX: 0000000000000000 RSI: 0000000020000440 RDI: 0000000000000005 RBP: 00007f346bee7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe7afb53af R14: 00007f346cc82300 R15: 0000000000022000