====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc5-syzkaller-32269-g9500fc6e9e60 #0 Not tainted ------------------------------------------------------ syz-executor.3/8706 is trying to acquire lock: ffff000114950350 (&ndev->req_lock){+.+.}-{3:3}, at: nci_request net/nfc/nci/core.c:148 [inline] ffff000114950350 (&ndev->req_lock){+.+.}-{3:3}, at: nci_set_local_general_bytes+0xbc/0x480 net/nfc/nci/core.c:774 but task is already holding lock: ffff000114954518 (&genl_data->genl_data_mutex){+.+.}-{3:3}, at: nfc_genl_start_poll+0xc4/0x174 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}: __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 nfc_urelease_event_work+0x88/0x16c net/nfc/netlink.c:1811 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863 -> #2 (nfc_devlist_mutex){+.+.}-{3:3}: __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 nfc_register_device+0x34/0x208 net/nfc/core.c:1116 nci_register_device+0x338/0x3b0 net/nfc/nci/core.c:1256 virtual_ncidev_open+0x6c/0xd8 drivers/nfc/virtual_ncidev.c:146 misc_open+0x1b8/0x200 drivers/char/misc.c:143 chrdev_open+0x2b4/0x2e8 fs/char_dev.c:414 do_dentry_open+0x364/0x748 fs/open.c:882 vfs_open+0x38/0x48 fs/open.c:1013 do_open fs/namei.c:3557 [inline] path_openat+0xe34/0x11c4 fs/namei.c:3713 do_filp_open+0xdc/0x1b8 fs/namei.c:3740 do_sys_openat2+0xb8/0x22c 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] __arm64_sys_openat+0xb0/0xe0 fs/open.c:1337 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 -> #1 (nci_mutex){+.+.}-{3:3}: __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 virtual_nci_close+0x28/0x58 drivers/nfc/virtual_ncidev.c:44 nci_open_device+0x414/0x518 net/nfc/nci/core.c:544 nci_dev_up+0x20/0x30 net/nfc/nci/core.c:631 nfc_dev_up+0xcc/0x1b0 net/nfc/core.c:118 nfc_genl_dev_up+0x40/0x78 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+0x458/0x4f4 net/netlink/genetlink.c:850 netlink_rcv_skb+0xe8/0x1d4 net/netlink/af_netlink.c:2540 genl_rcv+0x38/0x50 net/netlink/genetlink.c:861 netlink_unicast_kernel+0xfc/0x1dc net/netlink/af_netlink.c:1319 netlink_unicast+0x164/0x248 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x484/0x584 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x2f8/0x440 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x1ac/0x228 net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __arm64_sys_sendmsg+0x2c/0x3c net/socket.c:2572 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 -> #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 kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x1530/0x3084 kernel/locking/lockdep.c:5055 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668 __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 nci_request net/nfc/nci/core.c:148 [inline] nci_set_local_general_bytes+0xbc/0x480 net/nfc/nci/core.c:774 nci_start_poll+0x1e8/0x474 net/nfc/nci/core.c:838 nfc_start_poll+0xfc/0x170 net/nfc/core.c:225 nfc_genl_start_poll+0xd4/0x174 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+0x458/0x4f4 net/netlink/genetlink.c:850 netlink_rcv_skb+0xe8/0x1d4 net/netlink/af_netlink.c:2540 genl_rcv+0x38/0x50 net/netlink/genetlink.c:861 netlink_unicast_kernel+0xfc/0x1dc net/netlink/af_netlink.c:1319 netlink_unicast+0x164/0x248 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x484/0x584 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x2f8/0x440 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x1ac/0x228 net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __arm64_sys_sendmsg+0x2c/0x3c net/socket.c:2572 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 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.3/8706: #0: ffff80000d8c6268 (cb_lock){++++}-{3:3}, at: genl_rcv+0x28/0x50 net/netlink/genetlink.c:860 #1: ffff80000d8c6178 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffff80000d8c6178 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x80/0x4f4 net/netlink/genetlink.c:848 #2: ffff000114954518 (&genl_data->genl_data_mutex){+.+.}-{3:3}, at: nfc_genl_start_poll+0xc4/0x174 net/nfc/netlink.c:826 #3: ffff000114954100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff000114954100 (&dev->mutex){....}-{3:3}, at: nfc_start_poll+0x5c/0x170 net/nfc/core.c:208 stack backtrace: CPU: 1 PID: 8706 Comm: syz-executor.3 Not tainted 6.1.0-rc5-syzkaller-32269-g9500fc6e9e60 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2055 check_noncircular+0x14c/0x154 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 kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x1530/0x3084 kernel/locking/lockdep.c:5055 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668 __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 nci_request net/nfc/nci/core.c:148 [inline] nci_set_local_general_bytes+0xbc/0x480 net/nfc/nci/core.c:774 nci_start_poll+0x1e8/0x474 net/nfc/nci/core.c:838 nfc_start_poll+0xfc/0x170 net/nfc/core.c:225 nfc_genl_start_poll+0xd4/0x174 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+0x458/0x4f4 net/netlink/genetlink.c:850 netlink_rcv_skb+0xe8/0x1d4 net/netlink/af_netlink.c:2540 genl_rcv+0x38/0x50 net/netlink/genetlink.c:861 netlink_unicast_kernel+0xfc/0x1dc net/netlink/af_netlink.c:1319 netlink_unicast+0x164/0x248 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x484/0x584 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x2f8/0x440 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x1ac/0x228 net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __arm64_sys_sendmsg+0x2c/0x3c net/socket.c:2572 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584