bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) INFO: task kworker/u4:4:879 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:4 D25496 879 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 __flush_work+0x4bb/0x8b0 kernel/workqueue.c:2926 flush_all_backlogs net/core/dev.c:5283 [inline] rollback_registered_many+0x4b1/0xe70 net/core/dev.c:8181 unregister_netdevice_many.part.0+0x1a/0x300 net/core/dev.c:9324 unregister_netdevice_many+0x36/0x50 net/core/dev.c:9323 sit_exit_batch_net+0x543/0x700 net/ipv6/sit.c:1893 ops_exit_list+0xf9/0x150 net/core/net_namespace.c:156 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:554 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 5 locks held by kworker/u4:4/879: #0: 0000000090658dfb ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000146d6500 (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000e4f99763 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 #3: 00000000b44895b8 (rtnl_mutex){+.+.}, at: sit_exit_batch_net+0x88/0x700 net/ipv6/sit.c:1889 #4: 00000000545a7159 (cpu_hotplug_lock.rw_sem){++++}, at: get_online_cpus include/linux/cpu.h:137 [inline] #4: 00000000545a7159 (cpu_hotplug_lock.rw_sem){++++}, at: flush_all_backlogs net/core/dev.c:5276 [inline] #4: 00000000545a7159 (cpu_hotplug_lock.rw_sem){++++}, at: rollback_registered_many+0x3a8/0xe70 net/core/dev.c:8181 1 lock held by khungtaskd/1571: #0: 000000009e3ea3f6 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7841: #0: 0000000012b6fb43 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by agetty/7858: #0: 00000000418e3050 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 0000000047ebcb37 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154 3 locks held by kworker/1:4/9394: #0: 0000000065d74843 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000b5ddd3b8 (deferred_process_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000b44895b8 (rtnl_mutex){+.+.}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:150 7 locks held by syz-executor.3/1839: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1571 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1839 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:find_match.part.0+0x1e3/0x1530 net/ipv6/route.c:682 Code: 81 e7 00 00 40 00 44 89 fe e8 f9 fe 5a fa 45 85 ff 0f 85 fa 00 00 00 e8 7b fd 5a fa 44 89 ee 44 89 e2 48 89 df e8 4d 3f ff ff ff ff ff ff 41 89 c5 89 c6 e8 ce fe 5a fa 41 83 fd ff 0f 84 57 RSP: 0018:ffff8880ba006c48 EFLAGS: 00000292 RAX: 00000000fffffffd RBX: ffff88803ab19b40 RCX: ffffffff8706c805 RDX: 0000000000000100 RSI: ffffffff8706c88e RDI: 0000000000000005 RBP: ffff8880ba006cf0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000003 R13: 000000000000000d R14: ffff88803ab19b94 R15: 0000000000000000 FS: 00007fc838ce8700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555559a0848 CR3: 0000000009e6d000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_match net/ipv6/route.c:670 [inline] find_rr_leaf net/ipv6/route.c:719 [inline] rt6_select net/ipv6/route.c:769 [inline] fib6_table_lookup+0x4c2/0xf40 net/ipv6/route.c:1876 ip6_pol_route+0x180/0x1270 net/ipv6/route.c:1909 fib6_rule_lookup+0x10b/0x4e0 net/ipv6/fib6_rules.c:118 ip6_route_input_lookup net/ipv6/route.c:1990 [inline] ip6_route_input+0x6c0/0xaa0 net/ipv6/route.c:2125 ip6_rcv_finish_core.constprop.0.isra.0+0xd7/0x550 net/ipv6/ip6_input.c:63 ip6_rcv_finish+0x176/0x2f0 net/ipv6/ip6_input.c:74 ip_sabotage_in net/bridge/br_netfilter_hooks.c:847 [inline] ip_sabotage_in+0x17d/0x1d0 net/bridge/br_netfilter_hooks.c:841 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline] nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:511 nf_hook include/linux/netfilter.h:244 [inline] NF_HOOK include/linux/netfilter.h:287 [inline] ipv6_rcv+0x26a/0x3f0 net/ipv6/ip6_input.c:273 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:4954 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5066 netif_receive_skb_internal+0xf0/0x3f0 net/core/dev.c:5156 NF_HOOK include/linux/netfilter.h:289 [inline] br_pass_frame_up+0x309/0x6c0 net/bridge/br_input.c:69 br_handle_frame_finish+0x6f2/0x1410 net/bridge/br_input.c:173 br_nf_hook_thresh+0x2a3/0x330 net/bridge/br_netfilter_hooks.c:1014 br_nf_pre_routing_finish_ipv6+0x6e3/0xd40 net/bridge/br_netfilter_ipv6.c:210 NF_HOOK include/linux/netfilter.h:289 [inline] br_nf_pre_routing_ipv6+0x3f4/0x860 net/bridge/br_netfilter_ipv6.c:240 br_nf_pre_routing+0xf05/0x1500 net/bridge/br_netfilter_hooks.c:494 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline] nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:511 nf_hook include/linux/netfilter.h:244 [inline] NF_HOOK include/linux/netfilter.h:287 [inline] br_handle_frame+0xa60/0x13b0 net/bridge/br_input.c:306 __netif_receive_skb_core+0x929/0x3270 net/core/dev.c:4876 __netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:4952 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5066 process_backlog+0x241/0x700 net/core/dev.c:5849 napi_poll net/core/dev.c:6280 [inline] net_rx_action+0x4ac/0xfb0 net/core/dev.c:6346 __do_softirq+0x265/0x980 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:lock_acquire+0x1ec/0x3c0 kernel/locking/lockdep.c:3911 Code: 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 b7 01 00 00 48 83 3d 09 2e a6 08 00 0f 84 2a 01 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 65 8b RSP: 0018:ffff888036b07668 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13e3051 RBX: ffff8880a9c72200 RCX: ff934e6a97baa5c9 RDX: dffffc0000000000 RSI: 000000009dc2ee2c RDI: 0000000000000286 RBP: ffffffff89f85fa0 R08: 0000000031958bc5 R09: 0000000000000001 R10: ffff8880a9c72ab0 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:242 [inline] rcu_read_lock include/linux/rcupdate.h:627 [inline] lock_page_memcg+0x36/0x220 mm/memcontrol.c:1908 page_remove_file_rmap+0x36/0xa30 mm/rmap.c:1212 page_remove_rmap+0xe5/0x120 mm/rmap.c:1297 zap_pte_range mm/memory.c:1350 [inline] zap_pmd_range mm/memory.c:1463 [inline] zap_pud_range mm/memory.c:1492 [inline] zap_p4d_range mm/memory.c:1513 [inline] unmap_page_range+0x147d/0x2c50 mm/memory.c:1534 unmap_single_vma+0x198/0x300 mm/memory.c:1579 unmap_vmas+0xa9/0x180 mm/memory.c:1609 exit_mmap+0x2b9/0x530 mm/mmap.c:3093 __mmput kernel/fork.c:1016 [inline] mmput+0x14e/0x4a0 kernel/fork.c:1037 exit_mm kernel/exit.c:549 [inline] do_exit+0xaec/0x2be0 kernel/exit.c:857 do_group_exit+0x125/0x310 kernel/exit.c:967 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fc83b772ae9 Code: Bad RIP value. RSP: 002b:00007fc838ce8188 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: 0000000000000008 RBX: 00007fc83b885f60 RCX: 00007fc83b772ae9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0 RBP: 00007fc83b7ccf6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc143b560f R14: 00007fc838ce8300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 81 e7 00 00 40 00 and $0x400000,%edi 6: 44 89 fe mov %r15d,%esi 9: e8 f9 fe 5a fa callq 0xfa5aff07 e: 45 85 ff test %r15d,%r15d 11: 0f 85 fa 00 00 00 jne 0x111 17: e8 7b fd 5a fa callq 0xfa5afd97 1c: 44 89 ee mov %r13d,%esi 1f: 44 89 e2 mov %r12d,%edx 22: 48 89 df mov %rbx,%rdi 25: e8 4d 3f ff ff callq 0xffff3f77 * 2a: bf ff ff ff ff mov $0xffffffff,%edi <-- trapping instruction 2f: 41 89 c5 mov %eax,%r13d 32: 89 c6 mov %eax,%esi 34: e8 ce fe 5a fa callq 0xfa5aff07 39: 41 83 fd ff cmp $0xffffffff,%r13d 3d: 0f .byte 0xf 3e: 84 .byte 0x84 3f: 57 push %rdi