INFO: task kworker/u8:10:1163 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:10 state:D stack:23880 pid:1163 tgid:1163 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1584 [inline] __writeback_single_inode+0x75a/0x10e0 fs/fs-writeback.c:1827 writeback_sb_inodes+0x979/0x19d0 fs/fs-writeback.c:2056 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2132 wb_writeback+0x459/0xb00 fs/fs-writeback.c:2243 wb_check_old_data_flush fs/fs-writeback.c:2347 [inline] wb_do_writeback fs/fs-writeback.c:2400 [inline] wb_workfn+0xb12/0xf10 fs/fs-writeback.c:2428 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 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 INFO: task syz-executor:5641 blocked for more than 166 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22264 pid:5641 tgid:5641 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240 __wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit include/linux/wait_bit.h:77 [inline] gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1268 gfs2_glock_nq_init fs/gfs2/glock.h:253 [inline] __gfs2_lookup+0x134/0x2a0 fs/gfs2/inode.c:998 __lookup_slow+0x2b7/0x410 fs/namei.c:1915 lookup_slow+0x53/0x70 fs/namei.c:1932 walk_component fs/namei.c:2278 [inline] lookup_last fs/namei.c:2785 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2809 filename_lookup+0x256/0x5d0 fs/namei.c:2838 user_path_at+0x40/0x160 fs/namei.c:3643 ksys_umount fs/namespace.c:2062 [inline] __do_sys_umount fs/namespace.c:2070 [inline] __se_sys_umount fs/namespace.c:2068 [inline] __x64_sys_umount+0xf6/0x170 fs/namespace.c:2068 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1b5bb9e097 RSP: 002b:00007ffd61427b08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f1b5bc321ca RCX: 00007f1b5bb9e097 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd61427bc0 RBP: 00007ffd61427bc0 R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd61428cb0 R13: 00007f1b5bc321ca R14: 0000000000030e39 R15: 00007ffd6142ae70 INFO: task syz.2.244:6818 blocked in I/O wait for more than 166 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.244 state:D stack:23000 pid:6818 tgid:6815 ppid:5639 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 io_schedule+0x7f/0xd0 kernel/sched/core.c:8110 __lock_metapage fs/jfs/jfs_metapage.c:52 [inline] lock_metapage+0x1ff/0x400 fs/jfs/jfs_metapage.c:66 __get_metapage+0x49a/0xe20 fs/jfs/jfs_metapage.c:749 xtSplitPage+0x281/0x2150 fs/jfs/jfs_xtree.c:989 xtSplitUp+0x33c/0x1fc0 fs/jfs/jfs_xtree.c:786 xtInsert+0x452/0xf20 fs/jfs/jfs_xtree.c:608 extAlloc+0xad9/0x1020 fs/jfs/jfs_extent.c:150 jfs_get_block+0x358/0xad0 fs/jfs/inode.c:254 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2042 block_write_begin+0x8d/0x120 fs/buffer.c:2153 jfs_write_begin+0x35/0x80 fs/jfs/inode.c:306 generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4325 generic_file_write_iter+0x14a/0x680 mm/filemap.c:4468 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8819b9ce59 RSP: 002b:00007f881aae0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f8819e15fa0 RCX: 00007f8819b9ce59 RDX: 000000000208e24b RSI: 0000200000000040 RDI: 000000000000000d RBP: 00007f8819c32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8819e16038 R14: 00007f8819e15fa0 R15: 00007ffd4ae94918 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e95cc20 (rcu_read_lock){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] , at: rcu_read_lock include/linux/rcupdate.h:838 [inline] , at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:10/1163: #0: ffff88801fed9940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801fed9940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000594fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000594fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff888078cec0d8 (&type->s_umount_key#57){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff88807656c878 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 2 locks held by getty/5383: #0: ffff8880328450a0 (&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/0x13a0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5641: #0: ffff88807654c760 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline] #0: ffff88807654c760 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1931 3 locks held by kworker/1:5/5795: #0: ffff88802268b940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88802268b940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc900048c7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc900048c7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802b1431d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b1431d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 5 locks held by syz.2.244/6818: #0: ffff8880324990b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1261 #1: ffff888078cec410 (sb_writers#17){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline] #1: ffff888078cec410 (sb_writers#17){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684 #2: ffff88807656cc18 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #2: ffff88807656cc18 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: generic_file_write_iter+0x11e/0x680 mm/filemap.c:4465 #3: ffff88807656c7f0 (&jfs_ip->rdwrlock#2){++++}-{4:4}, at: jfs_get_block+0x153/0xad0 fs/jfs/inode.c:219 #4: ffff88807656c878 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: extAlloc+0x130/0x1020 fs/jfs/jfs_extent.c:86 4 locks held by kworker/u8:18/8182: #0: ffff88813fe7c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88813fe7c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90003317c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90003317c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 #3: ffffffff8e962f28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #3: ffffffff8e962f28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 2 locks held by syz.3.634/8440: #0: ffffffff8f595860 (ppp_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xdf/0x1b20 drivers/net/ppp/ppp_generic.c:726 #1: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3367 [inline] #1: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1059 [inline] #1: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xa6a/0x1b20 drivers/net/ppp/ppp_generic.c:730 2 locks held by syz.3.634/8468: #0: ffffffff9031d838 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff9031d838 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff9031d838 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109 1 lock held by syz.3.634/8470: #0: ffffffff8f595860 (ppp_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xdf/0x1b20 drivers/net/ppp/ppp_generic.c:726 1 lock held by syz.3.634/8478: #0: ffffffff8f595860 (ppp_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xdf/0x1b20 drivers/net/ppp/ppp_generic.c:726 1 lock held by syz.4.640/8481: #0: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7003 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 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: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+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x389/0x470 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: cb 7e 02 e9 ee df 68 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 01 22 00 fb f4 c7 df 68 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000242 RAX: 00000000007835b5 RBX: ffffffff819a845a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dfa4398 RDI: ffffffff8c28b8e0 RBP: ffffc90000197f10 R08: ffff8880b87339db R09: 1ffff110170e673b R10: dffffc0000000000 R11: ffffed10170e673c R12: 0000000000000001 R13: 1ffff11003b54000 R14: 0000000000000001 R15: 1ffff11003b54000 FS: 0000000000000000(0000) GS:ffff88812539c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffee8c3ae80 CR3: 0000000077ad8000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147