INFO: task kworker/u8:4:78 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kerne[ 337.858571][ T38] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:4 state:D stack:20352 pid:78 tgid:78 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 io_schedule+0x80/0xe0 kernel/sched/core.c:8154 folio_wait_bit_common+0x83c/0xbc0 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1157 [inline] writeback_get_folio mm/page-writeback.c:2435 [inline] writeback_iter+0x957/0x1320 mm/page-writeback.c:2529 metapage_writepages+0x100/0x1a0 fs/jfs/jfs_metapage.c:558 do_writepages+0x338/0x560 mm/page-writeback.c:2571 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2079 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2155 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2266 wb_check_start_all fs/fs-writeback.c:2392 [inline] wb_do_writeback fs/fs-writeback.c:2439 [inline] wb_workfn+0x986/0x10f0 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 INFO: task jfsCommit:128 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:jfsCommit state:D stack:28808 pid:128 tgid:128 ppid:2 task_flags:0x200040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 io_schedule+0x80/0xe0 kernel/sched/core.c:8154 folio_wait_bit_common+0x83c/0xbc0 mm/filemap.c:1323 txUnlock+0x23f/0xdb0 fs/jfs/jfs_txnmgr.c:931 txLazyCommit fs/jfs/jfs_txnmgr.c:2684 [inline] jfs_lazycommit+0x533/0xa20 fs/jfs/jfs_txnmgr.c:2735 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 INFO: task syz.2.104:6345 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:syz.2.104 state:D stack:25640 pid:6345 tgid:6344 ppid:5602 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 io_schedule+0x80/0xe0 kernel/sched/core.c:8154 folio_wait_bit_common+0x83c/0xbc0 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1157 [inline] release_metapage+0x101/0xa50 fs/jfs/jfs_metapage.c:871 discard_metapage fs/jfs/jfs_metapage.h:88 [inline] __get_metapage+0x9ac/0xdf0 fs/jfs/jfs_metapage.c:754 dtSearch+0x56c/0x2010 fs/jfs/jfs_dtree.c:621 jfs_lookup+0x1b0/0x420 fs/jfs/namei.c:1464 __lookup_slow+0x1fb/0x2f0 fs/namei.c:1919 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd2a/0x1910 fs/namei.c:2656 path_lookupat+0xe4/0x8c0 fs/namei.c:2812 filename_lookup+0x265/0x5d0 fs/namei.c:2842 user_path_at+0x40/0x160 fs/namei.c:3641 do_mount fs/namespace.c:4171 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x2dc/0x420 fs/namespace.c:4367 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: 0033:0x7f12e3ecce59 RSP: 002b:00007f12e2126028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f12e4145fa0 RCX: 00007f12e3ecce59 RDX: 00002000000014c0 RSI: 0000200000001480 RDI: 0000000000000000 RBP: 00007f12e3f62e6f R08: 0000200000001580 R09: 0000000000000000 R10: 0000000000001002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f12e4146038 R14: 00007f12e4145fa0 R15: 00007ffd3c03db78 INFO: task syz.2.104:6347 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.104 state:D stack:25672 pid:6347 tgid:6344 ppid:5602 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rwbase_write_lock+0x3cf/0x720 kernel/locking/rwbase_rt.c:279 inode_lock_nested include/linux/fs.h:1069 [inline] __start_dirop fs/namei.c:2918 [inline] start_dirop fs/namei.c:2942 [inline] filename_create+0x200/0x370 fs/namei.c:4951 filename_mkdirat+0xd2/0x520 fs/namei.c:5298 __do_sys_mkdirat fs/namei.c:5326 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5323 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: 0033:0x7f12e3ecbcc7 RSP: 002b:00007f12e2104e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f12e2104ee0 RCX: 00007f12e3ecbcc7 RDX: 00000000000001ff RSI: 0000200000000000 RDI: 00000000ffffff9c RBP: 0000200000000040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000200000000000 R13: 00007f12e2104ea0 R14: 0000000000000000 R15: 0000200000002300 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000117c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000117c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 1 lock held by khungtaskd/38: #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/78: #0: ffff88801b2ab938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b2ab938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000159fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000159fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88802ba3c0d0 (&type->s_umount_key#71){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:566 8 locks held by kworker/u8:12/1526: 2 locks held by getty/5350: #0: ffff88803650e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:3/5612: 4 locks held by udevd/5802: 1 lock held by syz.2.104/6345: #0: ffff88804071c950 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff88804071c950 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 1 lock held by syz.2.104/6347: #0: ffff88804071c950 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #0: ffff88804071c950 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #0: ffff88804071c950 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #0: ffff88804071c950 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4951 2 locks held by syz.8.299/8022: 2 locks held by syz.8.299/8028: #0: ffff888059a4e500 (sb_writers#4){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888059a4e500 (sb_writers#4){.+.+}-{0:0}, at: vfs_fallocate+0x5e9/0x7f0 fs/open.c:337 #1: ffff88806c089bd8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff88806c089bd8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: ext4_fallocate+0x1e3/0x410 fs/ext4/extents.c:4883 2 locks held by syz.8.299/8057: 3 locks held by syz.6.300/8038: 3 locks held by syz.3.304/8043: 5 locks held by syz.9.303/8056: 1 lock held by modprobe/8058: ============================================= 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 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: 8056 Comm: syz.9.303 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x18fa/0x2ce0 kernel/locking/lockdep.c:5237 Code: 13 25 ff 0f 00 00 39 05 b0 d6 d7 11 73 06 89 05 a8 d6 d7 11 48 8b 02 48 89 df 4c 39 e8 0f 84 34 fe ff ff 4c 89 78 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 20 fe ff ff 48 89 fb 48 c7 c7 b0 02 e9 RSP: 0018:ffffc900044270e8 EFLAGS: 00000006 RAX: ffffffff96238b08 RBX: 00000000000003cd RCX: 00000000000000cd RDX: ffffffff95fcfc98 RSI: ffff88802d6d4af8 RDI: 00000000000003cd RBP: f1d61ef13ebbe0d9 R08: ffffc900044270b0 R09: 0000000000000020 R10: 0000000000000000 R11: ffffffff81a124a0 R12: 00000000000000cc R13: ffffffff931a7fc0 R14: ffff88802d6d3e00 R15: ffffffff96063b78 FS: 00007f90253ae6c0(0000) GS:ffff888126111000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000007000 CR3: 00000000414be000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 do_write_seqcount_begin_nested include/linux/seqlock.h:478 [inline] do_write_seqcount_begin include/linux/seqlock.h:504 [inline] psi_write_begin+0xab/0x160 kernel/sched/psi.c:183 psi_account_irqtime+0x1da/0x6d0 kernel/sched/psi.c:1030 __schedule+0x976/0x5500 kernel/sched/core.c:7227 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 class_preempt_destructor include/linux/preempt.h:468 [inline] raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:102 [inline] rtlock_slowlock kernel/locking/rtmutex.c:1923 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x316/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] __slab_free+0xf1/0x2a0 mm/slub.c:5713 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_lru_noprof+0x353/0x650 mm/slub.c:4978 fat_alloc_inode+0x30/0x100 fs/fat/inode.c:753 alloc_inode+0x6a/0x1b0 fs/inode.c:338 new_inode+0x1f/0x170 fs/inode.c:1174 fat_build_inode+0x20d/0x3f0 fs/fat/inode.c:604 vfat_create+0x184/0x270 fs/fat/namei_vfat.c:774 lookup_open fs/namei.c:4508 [inline] open_last_lookups fs/namei.c:4608 [inline] path_openat+0x1344/0x3850 fs/namei.c:4856 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_open fs/open.c:1382 [inline] __se_sys_open fs/open.c:1378 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1378 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: 0033:0x7f902715ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f90253ae028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f90273d5fa0 RCX: 00007f902715ce59 RDX: 0000000000000004 RSI: 0000000000066842 RDI: 0000200000000140 RBP: 00007f90271f2e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f90273d6038 R14: 00007f90273d5fa0 R15: 00007ffd094198e8