====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc1-syzkaller-00321-g0f2be57686c7 #0 Not tainted ------------------------------------------------------ syz.2.997/9625 is trying to acquire lock: ffff8880532f06f0 (&xs->mutex){+.+.}-{4:4}, at: xsk_notifier+0xcf/0x230 net/xdp/xsk.c:1648 but task is already holding lock: ffff888034bc9c98 (&net->xdp.lock){+.+.}-{4:4}, at: xsk_notifier+0x8b/0x230 net/xdp/xsk.c:1644 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&net->xdp.lock){+.+.}-{4:4}: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 xsk_notifier+0x8b/0x230 net/xdp/xsk.c:1644 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2264 [inline] call_netdevice_notifiers net/core/dev.c:2278 [inline] unregister_netdevice_many_notify+0x1572/0x2500 net/core/dev.c:12025 unregister_netdevice_many net/core/dev.c:12088 [inline] unregister_netdevice_queue+0x383/0x400 net/core/dev.c:11941 unregister_netdevice include/linux/netdevice.h:3373 [inline] _cfg80211_unregister_wdev+0x163/0x590 net/wireless/core.c:1256 ieee80211_remove_interfaces+0x4f1/0x700 net/mac80211/iface.c:2316 ieee80211_unregister_hw+0x5d/0x2c0 net/mac80211/main.c:1681 mac80211_hwsim_del_radio+0x2c6/0x4c0 drivers/net/wireless/virtual/mac80211_hwsim.c:5665 hwsim_exit_net+0x5c3/0x670 drivers/net/wireless/virtual/mac80211_hwsim.c:6545 ops_exit_list net/core/net_namespace.c:200 [inline] ops_undo_list+0x3f6/0x8b0 net/core/net_namespace.c:250 cleanup_net+0x530/0x940 net/core/net_namespace.c:684 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (&rdev->wiphy.mtx){+.+.}-{4:4}: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 class_wiphy_constructor include/net/cfg80211.h:6092 [inline] cfg80211_netdev_notifier_call+0x1b3/0x1430 net/wireless/core.c:1547 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2264 [inline] call_netdevice_notifiers net/core/dev.c:2278 [inline] __dev_close_many+0x15d/0x760 net/core/dev.c:1723 dev_close_many+0x250/0x4c0 net/core/dev.c:1777 unregister_netdevice_many_notify+0x628/0x2500 net/core/dev.c:11994 unregister_netdevice_many net/core/dev.c:12088 [inline] default_device_exit_batch+0x7ff/0x880 net/core/dev.c:12590 ops_exit_list net/core/net_namespace.c:206 [inline] ops_undo_list+0x47f/0x8b0 net/core/net_namespace.c:250 cleanup_net+0x530/0x940 net/core/net_namespace.c:684 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (&dev_instance_lock_key#3){+.+.}-{4:4}: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 netdev_lock include/linux/netdevice.h:2750 [inline] netdev_lock_ops include/net/netdev_lock.h:42 [inline] xsk_bind+0x2fd/0xfb0 net/xdp/xsk.c:1188 __sys_bind_socket net/socket.c:1810 [inline] __sys_bind+0x1de/0x290 net/socket.c:1841 __do_sys_bind net/socket.c:1846 [inline] __se_sys_bind net/socket.c:1844 [inline] __x64_sys_bind+0x7a/0x90 net/socket.c:1844 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&xs->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 xsk_notifier+0xcf/0x230 net/xdp/xsk.c:1648 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2264 [inline] call_netdevice_notifiers net/core/dev.c:2278 [inline] unregister_netdevice_many_notify+0x1572/0x2500 net/core/dev.c:12025 unregister_netdevice_many net/core/dev.c:12088 [inline] unregister_netdevice_queue+0x383/0x400 net/core/dev.c:11941 unregister_netdevice include/linux/netdevice.h:3373 [inline] ppp_release+0xed/0x1f0 drivers/net/ppp/ppp_generic.c:422 __fput+0x3e9/0x9f0 fs/file_table.c:465 task_work_run+0x251/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &xs->mutex --> &rdev->wiphy.mtx --> &net->xdp.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&net->xdp.lock); lock(&rdev->wiphy.mtx); lock(&net->xdp.lock); lock(&xs->mutex); *** DEADLOCK *** 2 locks held by syz.2.997/9625: #0: ffffffff900fe688 (rtnl_mutex){+.+.}-{4:4}, at: ppp_release+0x87/0x1f0 drivers/net/ppp/ppp_generic.c:420 #1: ffff888034bc9c98 (&net->xdp.lock){+.+.}-{4:4}, at: xsk_notifier+0x8b/0x230 net/xdp/xsk.c:1644 stack backtrace: CPU: 1 UID: 0 PID: 9625 Comm: syz.2.997 Not tainted 6.15.0-rc1-syzkaller-00321-g0f2be57686c7 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079 check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 xsk_notifier+0xcf/0x230 net/xdp/xsk.c:1648 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2264 [inline] call_netdevice_notifiers net/core/dev.c:2278 [inline] unregister_netdevice_many_notify+0x1572/0x2500 net/core/dev.c:12025 unregister_netdevice_many net/core/dev.c:12088 [inline] unregister_netdevice_queue+0x383/0x400 net/core/dev.c:11941 unregister_netdevice include/linux/netdevice.h:3373 [inline] ppp_release+0xed/0x1f0 drivers/net/ppp/ppp_generic.c:422 __fput+0x3e9/0x9f0 fs/file_table.c:465 task_work_run+0x251/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe75378e169 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff92de8ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fe7539b7ba0 RCX: 00007fe75378e169 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fe7539b7ba0 R08: 000000000000020c R09: 0000001e92de8e9f R10: 00007fe7539b7ac0 R11: 0000000000000246 R12: 00000000000374de R13: 00007fe7539b6160 R14: ffffffffffffffff R15: 00007fff92de8cc0