====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.12695/2028 is trying to acquire lock: ffffffff8f68d2b8 (nr_node_list_lock){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffffffff8f68d2b8 (nr_node_list_lock){+...}-{3:3}, at: nr_rt_device_down+0xa9/0x720 net/netrom/nr_route.c:517 but task is already holding lock: ffffffff8f68d258 (nr_neigh_list_lock){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffffffff8f68d258 (nr_neigh_list_lock){+...}-{3:3}, at: nr_rt_device_down+0x28/0x720 net/netrom/nr_route.c:514 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (nr_neigh_list_lock){+...}-{3:3}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_remove_neigh+0x25/0xe0 net/netrom/nr_route.c:307 nr_add_node+0x1d9f/0x2570 net/netrom/nr_route.c:249 nr_rt_ioctl+0xc12/0xd50 net/netrom/nr_route.c:651 sock_do_ioctl+0xdc/0x300 net/socket.c:1238 sock_ioctl+0x576/0x790 net/socket.c:1359 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&nr_node->node_lock){+...}-{3:3}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_node_lock include/net/netrom.h:152 [inline] nr_dec_obs net/netrom/nr_route.c:459 [inline] nr_rt_ioctl+0x193/0xd50 net/netrom/nr_route.c:692 sock_do_ioctl+0xdc/0x300 net/socket.c:1238 sock_ioctl+0x576/0x790 net/socket.c:1359 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (nr_node_list_lock){+...}-{3:3}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_rt_device_down+0xa9/0x720 net/netrom/nr_route.c:517 nr_device_event+0x137/0x150 net/netrom/af_netrom.c:126 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] netif_close_many+0x29c/0x410 net/core/dev.c:1784 netif_close+0x158/0x210 net/core/dev.c:1797 dev_close+0x10a/0x220 net/core/dev_api.c:220 bpq_device_event+0x377/0x6a0 drivers/net/hamradio/bpqether.c:528 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] netif_close_many+0x29c/0x410 net/core/dev.c:1784 netif_close+0x158/0x210 net/core/dev.c:1797 dev_close+0x10a/0x220 net/core/dev_api.c:220 bond_setup_by_slave+0x5f/0x3f0 drivers/net/bonding/bond_main.c:1639 bond_enslave+0x7a0/0x3a20 drivers/net/bonding/bond_main.c:2051 bond_do_ioctl+0x635/0x9b0 drivers/net/bonding/bond_main.c:4714 bond_siocdevprivate+0x17e/0x350 drivers/net/bonding/bond_main.c:-1 dev_siocdevprivate net/core/dev_ioctl.c:521 [inline] dev_ifsioc+0xb54/0xf00 net/core/dev_ioctl.c:633 dev_ioctl+0x84c/0x1150 net/core/dev_ioctl.c:851 sock_ioctl+0x719/0x790 net/socket.c:1284 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: nr_node_list_lock --> &nr_node->node_lock --> nr_neigh_list_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(nr_neigh_list_lock); lock(&nr_node->node_lock); lock(nr_neigh_list_lock); lock(nr_node_list_lock); *** DEADLOCK *** 2 locks held by syz.1.12695/2028: #0: ffffffff8f537c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f537c08 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x83c/0x1150 net/core/dev_ioctl.c:850 #1: ffffffff8f68d258 (nr_neigh_list_lock){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffffffff8f68d258 (nr_neigh_list_lock){+...}-{3:3}, at: nr_rt_device_down+0x28/0x720 net/netrom/nr_route.c:514 stack backtrace: CPU: 0 UID: 0 PID: 2028 Comm: syz.1.12695 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_rt_device_down+0xa9/0x720 net/netrom/nr_route.c:517 nr_device_event+0x137/0x150 net/netrom/af_netrom.c:126 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] netif_close_many+0x29c/0x410 net/core/dev.c:1784 netif_close+0x158/0x210 net/core/dev.c:1797 dev_close+0x10a/0x220 net/core/dev_api.c:220 bpq_device_event+0x377/0x6a0 drivers/net/hamradio/bpqether.c:528 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] netif_close_many+0x29c/0x410 net/core/dev.c:1784 netif_close+0x158/0x210 net/core/dev.c:1797 dev_close+0x10a/0x220 net/core/dev_api.c:220 bond_setup_by_slave+0x5f/0x3f0 drivers/net/bonding/bond_main.c:1639 bond_enslave+0x7a0/0x3a20 drivers/net/bonding/bond_main.c:2051 bond_do_ioctl+0x635/0x9b0 drivers/net/bonding/bond_main.c:4714 bond_siocdevprivate+0x17e/0x350 drivers/net/bonding/bond_main.c:-1 dev_siocdevprivate net/core/dev_ioctl.c:521 [inline] dev_ifsioc+0xb54/0xf00 net/core/dev_ioctl.c:633 dev_ioctl+0x84c/0x1150 net/core/dev_ioctl.c:851 sock_ioctl+0x719/0x790 net/socket.c:1284 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faeb598ebe9 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:00007faeb67ec038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007faeb5bb5fa0 RCX: 00007faeb598ebe9 RDX: 0000200000000180 RSI: 00000000000089f0 RDI: 0000000000000004 RBP: 00007faeb5a11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faeb5bb6038 R14: 00007faeb5bb5fa0 R15: 00007ffe5f48f8a8 8021q: adding VLAN 0 to HW filter on device bond0 bond0: (slave rose0): Enslaving as an active interface with an up link