INFO: task syz-executor:19257 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22576 pid:19257 tgid:19257 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 wb_wait_for_completion+0x3b2/0x700 fs/fs-writeback.c:227 sync_inodes_sb+0x224/0xbf0 fs/fs-writeback.c:3030 sync_filesystem+0x17a/0x230 fs/sync.c:64 generic_shutdown_super+0x77/0x2d0 fs/super.c:626 kill_block_super+0x44/0x90 fs/super.c:1665 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2286 deactivate_locked_super+0xbc/0x130 fs/super.c:477 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcc9f79f097 RSP: 002b:00007ffd38c9da18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fcc9f8332ca RCX: 00007fcc9f79f097 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd38c9dad0 RBP: 00007ffd38c9dad0 R08: 00007ffd38c9ead0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd38c9eb60 R13: 00007fcc9f8332ca R14: 000000000010fc4a R15: 00007ffd38c9eba0 Showing all locks held in the system: 1 lock held by ksoftirqd/1/23: 6 locks held by kworker/1:2/30: #0: ffff8880b863b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:675 #1: ffff8880b8724440 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933 #2: ffff88801e6c80c0 (&ACCESS_PRIVATE(ssp->srcu_sup, lock)){-...}-{2:2}, at: srcu_reschedule+0x44/0x1d0 kernel/rcu/srcutree.c:1944 #3: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #3: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: mld_newpack+0x2d4/0xcb0 net/ipv6/mcast.c:1797 #4: ffff8880b8724440 (psi_seq){-.-.}-{0:0}, at: psi_task_change+0xc9/0x320 kernel/sched/psi.c:919 #5: ffff88802e498a90 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:572 [inline] #5: ffff88802e498a90 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x67/0x14d0 kernel/sched/core.c:4292 1 lock held by khungtaskd/32: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5375: #0: ffff88803580f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 9 locks held by kworker/u8:11/14917: 2 locks held by kworker/u8:14/14918: #0: ffff8880b863b160 ( &rq->__lock ){-.-.}-{2:2} , at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:675 #1: ffff8880b8624440 ( psi_seq ){-.-.}-{0:0} , at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933 3 locks held by kworker/u8:18/14919: #0: ffff88801b064140 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3297 [inline] , at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc900043a7c40 ( (work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] (work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 3 locks held by kworker/u8:19/14920: #0: ffff88803197e140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88803197e140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc900042c7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc900042c7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff9002c0c0 ( rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x116/0x15c0 net/ipv6/addrconf.c:4229 2 locks held by syz-executor/19257: #0: ffff88806227c0d8 (&type->s_umount_key#66){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88806227c0d8 (&type->s_umount_key#66){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88806227c0d8 (&type->s_umount_key#66){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:509 #1: ffff888026212870 ( &bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:396 [inline] &bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x208/0xbf0 fs/fs-writeback.c:3028 2 locks held by syz-executor/21501: #0: ffffffff9002c0c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff9002c0c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff9002c0c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 #1: ffff88805a6b1610 (&wg->device_update_lock ){+.+.}-{4:4} , at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 14917 Comm: kworker/u8:11 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: writeback wb_workfn (flush-7:9) RIP: 0010:get_desc_state kernel/printk/printk_ringbuffer.c:435 [inline] RIP: 0010:desc_read+0x126/0x3f0 kernel/printk/printk_ringbuffer.c:462 Code: 50 81 8d 00 49 bf ff ff ff ff ff ff ff 3f 4c 8b 65 00 4d 89 e5 4d 21 fd 48 8b 1c 24 48 89 df 4c 89 ee e8 dd f6 1f 00 4c 89 e0 <48> c1 e8 3e 4c 39 eb 41 bd ff ff ff ff 44 0f 44 e8 41 8d 5d ff bf RSP: 0018:ffffc90004475820 EFLAGS: 00000293 RAX: 8000000000004310 RBX: 0000000000004310 RCX: ffff88801ffa0000 RDX: 0000000000000000 RSI: 0000000000004310 RDI: 0000000000004310 RBP: ffffffff8ea386a0 R08: ffffffff8ea386a7 R09: 1ffffffff1d470d4 R10: dffffc0000000000 R11: fffffbfff1d470d5 R12: 8000000000004310 R13: 0000000000004310 R14: 1ffffffff1d470d4 R15: 3fffffffffffffff FS: 0000000000000000(0000) GS:ffff888124f58000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbfc37ed2f8 CR3: 000000005a4ac000 CR4: 0000000000350ef0 Call Trace: desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1934 [inline] prb_read kernel/printk/printk_ringbuffer.c:2002 [inline] _prb_read_valid+0x77f/0xa50 kernel/printk/printk_ringbuffer.c:2173 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2245 printk_get_next_message+0x18b/0x880 kernel/printk/printk.c:3052 console_emit_next_record kernel/printk/printk.c:3137 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x4e3/0xaf0 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 __xfs_printk fs/xfs/xfs_message.c:24 [inline] _xfs_alert_tag+0x1d6/0x2e0 fs/xfs/xfs_message.c:74 xfs_buf_verifier_error+0x150/0x2a0 fs/xfs/xfs_error.c:319 xfs_agfl_read_verify+0x17f/0x200 fs/xfs/libxfs/xfs_alloc.c:-1 xfs_buf_ioend+0x31b/0x750 fs/xfs/xfs_buf.c:1119 xfs_buf_iowait+0x133/0x420 fs/xfs/xfs_buf.c:1316 _xfs_buf_read fs/xfs/xfs_buf.c:621 [inline] xfs_buf_read_map+0x31f/0xa00 fs/xfs/xfs_buf.c:687 xfs_trans_read_buf_map+0x235/0x820 fs/xfs/xfs_trans_buf.c:273 xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline] xfs_alloc_read_agfl+0x22c/0x440 fs/xfs/libxfs/xfs_alloc.c:885 xfs_alloc_fix_freelist+0x1183/0x1c60 fs/xfs/libxfs/xfs_alloc.c:2961 xfs_alloc_vextent_prepare_ag+0xda/0x650 fs/xfs/libxfs/xfs_alloc.c:3566 xfs_alloc_vextent_iterate_ags+0x147/0x960 fs/xfs/libxfs/xfs_alloc.c:3750 xfs_alloc_vextent_start_ag+0x373/0x850 fs/xfs/libxfs/xfs_alloc.c:3839 xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3617 [inline] xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3661 [inline] xfs_bmapi_allocate+0x18d1/0x2f20 fs/xfs/libxfs/xfs_bmap.c:3936 xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4445 [inline] xfs_bmapi_convert_delalloc+0x879/0x1540 fs/xfs/libxfs/xfs_bmap.c:4501 xfs_map_blocks fs/xfs/xfs_aops.c:461 [inline] xfs_writeback_range+0x6ab/0xf80 fs/xfs/xfs_aops.c:505 iomap_writeback_range fs/iomap/buffered-io.c:1862 [inline] iomap_writeback_folio+0x14f1/0x2790 fs/iomap/buffered-io.c:1988 iomap_writepages+0x167/0x2e0 fs/iomap/buffered-io.c:2051 xfs_vm_writepages+0x2eb/0x3d0 fs/xfs/xfs_aops.c:719 do_writepages+0x338/0x560 mm/page-writeback.c:2571 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787 writeback_sb_inodes+0x9de/0x1b00 fs/fs-writeback.c:2079 wb_writeback+0x41c/0xad0 fs/fs-writeback.c:2264 wb_do_writeback fs/fs-writeback.c:2432 [inline] wb_workfn+0x431/0x10f0 fs/fs-writeback.c:2477 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245