INFO: task khugepaged:33 blocked for more than 143 seconds. Not tainted 5.15.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:khugepaged state:D stack:23984 pid: 33 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x174/0x270 kernel/sched/completion.c:138 __flush_work+0x56c/0xb10 kernel/workqueue.c:3084 __lru_add_drain_all+0x3fd/0x760 mm/swap.c:848 khugepaged_do_scan mm/khugepaged.c:2222 [inline] khugepaged+0x112/0x5390 mm/khugepaged.c:2283 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b983a20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by khugepaged/33: #0: ffffffff8ba6b428 (lock#5){+.+.}-{3:3}, at: __lru_add_drain_all+0x65/0x760 mm/swap.c:797 1 lock held by in:imklog/6216: 2 locks held by rs:main Q:Reg/6218: #0: ffff8880119dfc70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 #1: ffff88814aeca460 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:643 5 locks held by syz-executor.1/24905: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 24905 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:seqcount_lockdep_reader_access include/linux/seqlock.h:105 [inline] RIP: 0010:timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] RIP: 0010:timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] RIP: 0010:ktime_get_update_offsets_now+0x178/0x5c0 kernel/time/timekeeping.c:2300 Code: 8b 74 24 78 48 c7 c7 c8 2d 9a 8b e8 52 ed f4 ff 5a e8 0c d9 0f 00 9c 41 5c 41 81 e4 00 02 00 00 31 ff 4c 89 e6 e8 88 db 0f 00 <4d> 85 e4 0f 85 61 03 00 00 e8 ea d8 0f 00 31 ff 48 89 de e8 70 db RSP: 0018:ffffc90000dbfa60 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88802708ba00 RDI: 0000000000000003 RBP: 000000000008e362 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8167ed78 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880b9d2a44c R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f7e0ef96700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c621000 CR3: 000000002c6af000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hrtimer_update_base kernel/time/hrtimer.c:631 [inline] hrtimer_interrupt+0x142/0x790 kernel/time/hrtimer.c:1793 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:dev_nit_active net/core/dev.c:2259 [inline] RIP: 0010:xmit_one net/core/dev.c:3584 [inline] RIP: 0010:dev_hard_start_xmit+0x5e2/0x920 net/core/dev.c:3606 Code: 0f 84 bf fd ff ff 48 8b 5c 24 08 e9 96 fa ff ff e8 23 ae 54 fa 48 8b 44 24 28 80 38 00 0f 85 02 03 00 00 49 8b 85 80 00 00 00 <48> 39 44 24 20 0f 85 b0 fa ff ff e9 bb fa ff ff e8 f9 ad 54 fa 65 RSP: 0018:ffffc90000dbfc60 EFLAGS: 00000246 RAX: ffff888013fba080 RBX: ffff8880294e5c80 RCX: 0000000000000100 RDX: ffff88802708ba00 RSI: ffffffff8723184d RDI: ffff8880294e5c80 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87232849 R11: 0000000000000000 R12: ffff88807d2c10c0 R13: ffff888013fba000 R14: ffff888013fba0e0 R15: 0000000000001000 __dev_queue_xmit+0x299a/0x3630 net/core/dev.c:4226 br_dev_queue_push_xmit+0x25a/0x740 net/bridge/br_forward.c:53 br_nf_dev_queue_xmit+0x41c/0x1f30 net/bridge/br_netfilter_hooks.c:808 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] br_nf_post_routing+0xf30/0x1b40 net/bridge/br_netfilter_hooks.c:854 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:619 nf_hook+0x3d4/0x680 include/linux/netfilter.h:262 NF_HOOK include/linux/netfilter.h:305 [inline] br_forward_finish+0x7f/0xd0 net/bridge/br_forward.c:66 br_nf_hook_thresh+0x2a5/0x360 net/bridge/br_netfilter_hooks.c:1025 br_nf_forward_finish+0x7b3/0xc40 net/bridge/br_netfilter_hooks.c:564 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] br_nf_forward_ip net/bridge/br_netfilter_hooks.c:634 [inline] br_nf_forward_ip+0x538/0x1cb0 net/bridge/br_netfilter_hooks.c:575 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:619 nf_hook+0x3d4/0x680 include/linux/netfilter.h:262 NF_HOOK include/linux/netfilter.h:305 [inline] __br_forward+0x198/0x620 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0x331/0x430 net/bridge/br_forward.c:189 br_flood+0x13a/0x450 net/bridge/br_forward.c:231 br_handle_frame_finish+0xf66/0x1850 net/bridge/br_input.c:168 br_nf_hook_thresh+0x2a5/0x360 net/bridge/br_netfilter_hooks.c:1025 br_nf_pre_routing_finish_ipv6+0x684/0xe00 net/bridge/br_netfilter_ipv6.c:206 NF_HOOK include/linux/netfilter.h:307 [inline] br_nf_pre_routing_ipv6+0x42c/0x7b0 net/bridge/br_netfilter_ipv6.c:236 br_nf_pre_routing+0x1477/0x1ec0 net/bridge/br_netfilter_hooks.c:505 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_bridge_pre net/bridge/br_input.c:230 [inline] br_handle_frame+0x8f8/0x1180 net/bridge/br_input.c:370 __netif_receive_skb_core+0x9e1/0x3770 net/core/dev.c:5356 __netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5460 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5576 process_backlog+0x2a5/0x6c0 net/core/dev.c:6452 __napi_poll+0xaf/0x440 net/core/dev.c:7020 napi_poll net/core/dev.c:7087 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7174 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__local_bh_enable_ip+0xa8/0x120 kernel/softirq.c:390 Code: 1d 8d 90 bb 7e 65 8b 05 86 90 bb 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 b5 3b 09 00 e8 90 2a 37 00 fb 65 8b 05 68 90 bb 7e <85> c0 74 58 5b 5d c3 65 8b 05 b6 97 bb 7e 85 c0 75 a2 0f 0b eb 9e RSP: 0018:ffffc90002adf3a8 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 00000000fffffe01 RCX: 1ffffffff1ae1b29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff87d9ece1 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817e0a58 R11: 0000000000000001 R12: 0000000000000050 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000010 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:758 [inline] ip6_finish_output2+0x5bf/0x14e0 net/ipv6/ip6_output.c:127 ip6_fragment+0x2002/0x2700 net/ipv6/ip6_output.c:907 __ip6_finish_output net/ipv6/ip6_output.c:189 [inline] __ip6_finish_output+0x5fa/0x1050 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:450 [inline] ip6_local_out+0xaf/0x1a0 net/ipv6/output_core.c:161 ip6_send_skb+0xb7/0x340 net/ipv6/ip6_output.c:1912 udp_v6_send_skb+0x7c3/0x15e0 net/ipv6/udp.c:1249 udpv6_sendmsg+0x2319/0x2c40 net/ipv6/udp.c:1547 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:644 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f7e10020ae9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7e0ef96188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7e10133f60 RCX: 00007f7e10020ae9 RDX: 0000000000000000 RSI: 0000000020000480 RDI: 0000000000000003 RBP: 00007f7e1007aff7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffb8b3425f R14: 00007f7e0ef96300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 8b 74 24 78 mov 0x78(%rsp),%esi 4: 48 c7 c7 c8 2d 9a 8b mov $0xffffffff8b9a2dc8,%rdi b: e8 52 ed f4 ff callq 0xfff4ed62 10: 5a pop %rdx 11: e8 0c d9 0f 00 callq 0xfd922 16: 9c pushfq 17: 41 5c pop %r12 19: 41 81 e4 00 02 00 00 and $0x200,%r12d 20: 31 ff xor %edi,%edi 22: 4c 89 e6 mov %r12,%rsi 25: e8 88 db 0f 00 callq 0xfdbb2 * 2a: 4d 85 e4 test %r12,%r12 <-- trapping instruction 2d: 0f 85 61 03 00 00 jne 0x394 33: e8 ea d8 0f 00 callq 0xfd922 38: 31 ff xor %edi,%edi 3a: 48 89 de mov %rbx,%rsi 3d: e8 .byte 0xe8 3e: 70 db jo 0x1b