INFO: task kworker/1:1:43 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:1 state:D stack:19464 pid:43 tgid:43 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: xfs-sync/loop5 xfs_flush_inodes_worker Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2873 xfs_flush_inodes_worker+0x61/0x80 fs/xfs/xfs_super.c:648 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.5.1440:13057 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1440 state:D stack:21320 pid:13057 tgid:13038 ppid:7558 task_flags:0x400740 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4273 xfs_file_buffered_write+0x266/0x8a0 fs/xfs/xfs_file.c:997 __kernel_write_iter+0x428/0x910 fs/read_write.c:619 dump_emit_page fs/coredump.c:1298 [inline] dump_user_range+0x8a0/0xc90 fs/coredump.c:1372 elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111 coredump_write+0x116c/0x1900 fs/coredump.c:1049 vfs_coredump+0x1db5/0x2a60 fs/coredump.c:1170 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f413a38d710 RSP: 002b:00007f413b2a6b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f413a38d710 RDX: 0000000000000002 RSI: 00007f413b2a6c10 RDI: 00000000ffffff9c RBP: 00007f413b2a6c10 R08: 0000000000000000 R09: 00236962762f7665 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f413a5e6128 R14: 00007f413a5e6090 R15: 00007ffe27013538 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/1:1/43: #0: ffff888055938948 ((wq_completion)xfs-sync/loop5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888055938948 ((wq_completion)xfs-sync/loop5){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000b37ba0 ((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000b37ba0 ((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880286020e0 (&type->s_umount_key#78){++++}-{4:4}, at: xfs_flush_inodes_worker+0x45/0x80 fs/xfs/xfs_super.c:647 #3: ffff888142f10820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #3: ffff888142f10820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2871 3 locks held by kworker/u8:3/50: #0: ffff88802febd148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88802febd148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000bb7ba0 ( (work_completion)(&(&ifa->dad_work)->work) ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3239 [inline] , at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f73f388 ( rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194 8 locks held by kworker/u8:4/60: 2 locks held by getty/5624: #0: ffff88814d6600a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 ( &ldata->atomic_read_lock ){+.+.}-{4:4} , at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:8/5956: #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90005257ba0 ( (linkwatch_work).work ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3239 [inline] , at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f73f388 ( rtnl_mutex ){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 3 locks held by kworker/1:8/5979: #0: ffff88813fe59948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900052a7ba0 ( deferred_process_work ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3239 [inline] , at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f73f388 ( rtnl_mutex ){+.+.}-{4:4} , at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 5 locks held by kworker/u8:10/7209: #0: ffff88801bae6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801bae6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003ea7ba0 (net_cleanup_work){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3239 [inline] , at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f732250 ( pernet_ops_rwsem ){++++}-{4:4} , at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12820 #4: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #4: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 2 locks held by syz.5.1440/13057: #0: ffff888028602420 (sb_writers#13){.+.+}-{0:0}, at: vfs_coredump+0x1db5/0x2a60 fs/coredump.c:1170 #1: ffff8880550546b0 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: xfs_ilock+0xfe/0x390 fs/xfs/xfs_inode.c:149 1 lock held by syz-executor/13996: #0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/13998: #0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027 1 lock held by syz-executor/14000: #0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027 3 locks held by syz-executor/14004: #0: ffffffff8f7a4e90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f7a4ca8 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f7a4ca8 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f7a4ca8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 #2: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_register_hw+0x3037/0x40d0 net/mac80211/main.c:1534 2 locks held by syz.9.1648/14109: #0: ffffffff8f7a4e90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f7a4ca8 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f7a4ca8 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f7a4ca8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 60 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: writeback wb_workfn (flush-7:5) RIP: 0010:unwind_next_frame+0x50d/0x2390 arch/x86/kernel/unwind_orc.c:512 Code: 85 4d 18 00 00 4c 89 e0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 63 18 00 00 0f b7 1e c1 eb 0b 80 e3 01 48 8b 44 24 28 0f b6 04 28 <84> c0 4c 8b 7c 24 70 0f 85 6d 18 00 00 48 8b 44 24 10 88 18 0f b7 RSP: 0018:ffffc90000007458 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8fd7e2ac RDX: ffffffff90544790 RSI: ffffffff90544794 RDI: ffffffff8c03da00 RBP: dffffc0000000000 R08: 0000000000000003 R09: ffffffff81742d25 R10: ffffc90000007578 R11: ffffffff81acd510 R12: ffffffff90544795 R13: ffffc90000007578 R14: ffffc90000007528 R15: ffffffff81742d25 FS: 0000000000000000(0000) GS:ffff8881259fc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff20abaffc CR3: 000000000e138000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_netdev_trace_buffer+0xd4/0x5e0 net/core/dev.c:13141 __dev_hold include/linux/netdevice.h:4375 [inline] netdev_hold include/linux/netdevice.h:4418 [inline] dst_init+0x6f/0x460 net/core/dst.c:52 dst_alloc+0x12a/0x170 net/core/dst.c:93 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0x75/0x420 net/ipv6/route.c:3322 ndisc_send_skb+0x3f1/0x1510 net/ipv6/ndisc.c:491 addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4037 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x286/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2034 [inline] RIP: 0010:vprintk_emit+0x49d/0x590 kernel/printk/printk.c:2422 Code: 0f 84 34 ff ff ff e8 62 9a 1f 00 fb eb 44 e8 5a 9a 1f 00 e8 45 e1 de 09 4d 85 f6 74 94 e8 4b 9a 1f 00 fb 48 c7 c7 40 13 33 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 2b 3b RSP: 0018:ffffc9000211dd00 EFLAGS: 00000293 RAX: ffffffff81a0c0d5 RBX: ffffffff81a0bf2e RCX: ffff88801d778000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e331340 RBP: ffffc9000211de10 R08: ffffffff8fc35777 R09: 1ffffffff1f86aee R10: dffffc0000000000 R11: fffffbfff1f86aef R12: 0000000000000000 R13: 000000000000004b R14: 0000000000000200 R15: 1ffff92000423ba4 _printk+0xcf/0x120 kernel/printk/printk.c:2448 print_hex_dump+0x1a8/0x260 lib/hexdump.c:285 xfs_hex_dump+0x3d/0x50 fs/xfs/xfs_message.c:110 xfs_buf_verifier_error+0x1cc/0x2a0 fs/xfs/xfs_error.c:310 xfs_agfl_read_verify+0x165/0x1f0 fs/xfs/libxfs/xfs_alloc.c:-1 __xfs_buf_ioend+0x342/0x6f0 fs/xfs/xfs_buf.c:1174 xfs_buf_iowait+0x167/0x480 fs/xfs/xfs_buf.c:1381 _xfs_buf_read fs/xfs/xfs_buf.c:643 [inline] xfs_buf_read_map+0x335/0xa50 fs/xfs/xfs_buf.c:709 xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304 xfs_trans_read_buf fs/xfs/xfs_trans.h:210 [inline] xfs_alloc_read_agfl+0x202/0x410 fs/xfs/libxfs/xfs_alloc.c:885 xfs_alloc_fix_freelist+0xb93/0x1300 fs/xfs/libxfs/xfs_alloc.c:2961 xfs_alloc_vextent_prepare_ag+0xdb/0x610 fs/xfs/libxfs/xfs_alloc.c:3566 xfs_alloc_vextent_iterate_ags+0x140/0x940 fs/xfs/libxfs/xfs_alloc.c:3750 xfs_alloc_vextent_start_ag+0x388/0x850 fs/xfs/libxfs/xfs_alloc.c:3839 xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3619 [inline] xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3663 [inline] xfs_bmapi_allocate+0x188e/0x2e00 fs/xfs/libxfs/xfs_bmap.c:3938 xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4447 [inline] xfs_bmapi_convert_delalloc+0x7e2/0x1430 fs/xfs/libxfs/xfs_bmap.c:4503 xfs_map_blocks fs/xfs/xfs_aops.c:445 [inline] xfs_writeback_range+0x674/0xf70 fs/xfs/xfs_aops.c:489 iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline] iomap_writeback_folio+0xe75/0x1c80 fs/iomap/buffered-io.c:1718 iomap_writepages+0x162/0x2d0 fs/iomap/buffered-io.c:1770 xfs_vm_writepages+0x296/0x310 fs/xfs/xfs_aops.c:701 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195 wb_do_writeback fs/fs-writeback.c:2342 [inline] wb_workfn+0x409/0xef0 fs/fs-writeback.c:2382 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245