INFO: task syz.5.253:7739 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.253 state:D stack:24736 pid:7739 tgid:7737 ppid:6498 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 percpu_down_write+0x298/0x330 kernel/locking/percpu-rwsem.c:256 sb_wait_write fs/super.c:1850 [inline] freeze_super+0x535/0x1190 fs/super.c:2114 fs_bdev_freeze+0x1a3/0x310 fs/super.c:1542 bdev_freeze+0xd8/0x220 block/bdev.c:314 ntfs_force_shutdown fs/ntfs3/file.c:128 [inline] ntfs_ioctl_shutdown fs/ntfs3/file.c:146 [inline] ntfs_ioctl+0x53d/0x790 fs/ntfs3/file.c:170 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f96f64fc819 RSP: 002b:00007f96f474e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f96f6775fa0 RCX: 00007f96f64fc819 RDX: 00002000000001c0 RSI: 000000008004587d RDI: 0000000000000007 RBP: 00007f96f6592c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f96f6776038 R14: 00007f96f6775fa0 R15: 00007ffc90ef1258 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff888031d7d938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888031d7d938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000127c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000127c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 3 locks held by rcuc/1/28: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:16/2307: #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900076a7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900076a7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 4 locks held by kworker/u8:21/2312: #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90007747c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90007747c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f14e4c0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8f15cc78 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248 2 locks held by getty/5559: #0: ffff888036c270a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5802: 2 locks held by syz.5.253/7739: #0: ffff8880226aebd0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:305 #1: ffff888061fcc480 (sb_writers#13){++++}-{0:0}, at: sb_wait_write fs/super.c:1850 [inline] #1: ffff888061fcc480 (sb_writers#13){++++}-{0:0}, at: freeze_super+0x535/0x1190 fs/super.c:2114 3 locks held by syz.5.253/7746: 1 lock held by syz-executor/7905: 3 locks held by syz-executor/9584: 2 locks held by btrfs-cleaner/9636: #0: ffff888040020e18 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: cleaner_kthread+0x26d/0x510 fs/btrfs/disk-io.c:1441 #1: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x130 fs/kernfs/dir.c:1717 2 locks held by udevadm/9655: 1 lock held by modprobe/9657: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 7905 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:debug_lockdep_rcu_enabled+0x2c/0x40 kernel/rcu/update.c:320 Code: 1e fa 31 c0 83 3d a3 a4 46 04 00 74 1d 83 3d ba b6 46 04 00 74 14 65 48 8b 0d d8 d7 2a 07 31 c0 83 b9 b4 0b 00 00 00 0f 94 c0 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 RSP: 0018:ffffc9000e17f110 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffffff82302104 RCX: ffff888032c63d00 RDX: 000000005f479b93 RSI: ffffffff8d7c0ea8 RDI: ffffffff8ba67680 RBP: dffffc0000000000 R08: ffffffff81767e65 R09: ffffffff8ddcb9c0 R10: ffffc9000e17f238 R11: ffffffff81af9290 R12: 1ffff92001c2fe3d R13: ffffc9000e17f220 R14: ffffc9000e17f1e8 R15: ffffffff81767e65 FS: 000055557b163500(0000) GS:ffff888126336000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f719ebbf000 CR3: 0000000040734000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:851 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xcb/0x23c0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x124/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xe7b/0x1c70 mm/page_alloc.c:3040 folios_put_refs+0x56f/0x680 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x240/0x9e0 mm/shmem.c:1407 evict+0x61e/0xb10 fs/inode.c:846 __dentry_kill+0x1a2/0x5e0 fs/dcache.c:670 finish_dput+0xc9/0x480 fs/dcache.c:879 __fput+0x6a3/0xa90 fs/file_table.c:477 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:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f77d016d04e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffe903ccd08 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000055557b163500 RCX: 00007f77d016d04e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffe903ccdac R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000003d R13: 00000000000927c0 R14: 000000000005f51e R15: 00007ffe903cce00