INFO: task kworker/1:1H:5177 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:1H state:D stack:26488 pid:5177 tgid:5177 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: gfs2-glock/syz:syz glock_work_func Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 io_schedule+0x7f/0xd0 kernel/sched/core.c:7889 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250 __wait_on_bit_lock+0xec/0x4e0 kernel/sched/wait_bit.c:93 out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline] __lock_buffer fs/buffer.c:72 [inline] lock_buffer include/linux/buffer_head.h:432 [inline] discard_buffer fs/buffer.c:1603 [inline] block_invalidate_folio+0x370/0x730 fs/buffer.c:1660 folio_invalidate mm/truncate.c:140 [inline] truncate_cleanup_folio+0xcb/0x190 mm/truncate.c:160 truncate_inode_pages_range+0x2ce/0xe30 mm/truncate.c:404 inode_go_inval+0x13c/0x360 fs/gfs2/glops.c:366 do_xmote+0x289/0x760 fs/gfs2/glock.c:699 glock_work_func+0x2a8/0x580 fs/gfs2/glock.c:1011 process_one_work+0x9ab/0x1780 kernel/workqueue.c:3289 process_scheduled_works kernel/workqueue.c:3380 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3466 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 INFO: task kworker/1:2H:8393 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2H state:D stack:26984 pid:8393 tgid:8393 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: gfs2-glock/syz:syz glock_work_func Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 io_schedule+0x7f/0xd0 kernel/sched/core.c:7889 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250 __wait_on_bit_lock+0xec/0x4e0 kernel/sched/wait_bit.c:93 out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline] __lock_buffer fs/buffer.c:72 [inline] lock_buffer include/linux/buffer_head.h:432 [inline] discard_buffer fs/buffer.c:1603 [inline] block_invalidate_folio+0x370/0x730 fs/buffer.c:1660 folio_invalidate mm/truncate.c:140 [inline] truncate_cleanup_folio+0xcb/0x190 mm/truncate.c:160 truncate_inode_pages_range+0x2ce/0xe30 mm/truncate.c:404 do_xmote+0x289/0x760 fs/gfs2/glock.c:699 glock_work_func+0x2a8/0x580 fs/gfs2/glock.c:1011 process_one_work+0x9ab/0x1780 kernel/workqueue.c:3289 process_scheduled_works kernel/workqueue.c:3380 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3466 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 INFO: task syz-executor:8709 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20880 pid:8709 tgid:8709 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_timeout+0xc3/0x2c0 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+0x2cc/0x5e0 kernel/sched/completion.c:153 __flush_work+0xa17/0xc50 kernel/workqueue.c:4359 gfs2_clear_rgrpd+0x117/0x740 fs/gfs2/rgrp.c:731 gfs2_put_super+0x7d1/0x860 fs/gfs2/super.c:637 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 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:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [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: 0033:0x7f5a26b9d9d7 RSP: 002b:00007fff8defaef8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f5a26c32050 RCX: 00007f5a26b9d9d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff8defafb0 RBP: 00007fff8defafb0 R08: 00007fff8defbfb0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff8defc040 R13: 00007f5a26c32050 R14: 0000000000063a36 R15: 00007fff8defc080 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:5/96: 3 locks held by kworker/u8:6/143: 3 locks held by kworker/u8:8/1176: 2 locks held by kworker/1:1H/5177: #0: ffff888056409940 ((wq_completion)gfs2-glock/syz:syz){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc90003027c40 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 2 locks held by dhcpcd/5507: #0: ffff888028afd6e8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 2 locks held by getty/5595: #0: ffff8880371ea0a0 (&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by kworker/1:2H/8393: #0: ffff888056409940 ((wq_completion)gfs2-glock/syz:syz){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc90005bb7c40 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 1 lock held by syz-executor/8709: #0: ffff8880557f80d8 (&type->s_umount_key#59){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880557f80d8 (&type->s_umount_key#59){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880557f80d8 (&type->s_umount_key#59){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 3 locks held by syz.0.752/8976: #0: ffffffff8fc44288 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ea87940 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b5/0x9a0 fs/nfsd/nfsctl.c:1607 #2: ffffffff8e7637b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 2 locks held by kworker/0:7/9137: 4 locks held by kworker/u8:9/10032: #0: ffff88801c2b6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc90004217c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 #2: ffffffff8fbc6d68 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8e7637b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 8 locks held by syz-executor/11195: #0: ffff8880335fe410 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff8880335fe410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684 #1: ffff888033e35080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343 #2: ffff8880295a55a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880295a55a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344 #3: ffffffff8f448200 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88803244c0e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:941 [inline] #4: ffff88803244c0e0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline] #4: ffff88803244c0e0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x860 drivers/base/dd.c:1304 #5: ffff88803244f258 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1778 #6: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x10b/0x730 drivers/net/netdevsim/netdev.c:1177 #7: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #7: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 2 locks held by syz-executor/11390: #0: ffffffff8f336008 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8f336008 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8f336008 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 ============================================= 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 02/12/2026 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: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+0x1002/0x1060 kernel/hung_task.c:561 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: 9137 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events free_obj_work RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x6c/0xb0 kernel/rcu/tree.c:752 Code: 84 00 48 c7 c3 98 e9 1f 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 29 e3 72 11 74 11 83 e0 04 e8 02 5b 41 5e 41 5f e9 07 a4 0b 0a cc e8 d1 fd 87 ff eb e8 48 RSP: 0018:ffffc900033874f8 EFLAGS: 00000202 RAX: 0000000000000004 RBX: ffff8880b8633998 RCX: 0000000080000001 RDX: ffffc90003387601 RSI: ffffffff8c284de0 RDI: ffffffff8c284da0 RBP: dffffc0000000000 R08: ffffc900033876d0 R09: 0000000000000000 R10: ffffc90003387698 R11: fffff52000670ed5 R12: ffffc900033876e0 R13: ffffc90003380000 R14: ffffffff8e1f6790 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125435000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005640c5e71660 CR3: 0000000035662000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:879 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1a66/0x23c0 arch/x86/kernel/unwind_orc.c:695 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6242 [inline] kmem_cache_free+0x189/0x640 mm/slub.c:6369 free_object_list lib/debugobjects.c:333 [inline] free_obj_work+0x391/0x4c0 lib/debugobjects.c:537 process_one_work+0x9ab/0x1780 kernel/workqueue.c:3289 process_scheduled_works kernel/workqueue.c:3380 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3466 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