INFO: task syz.0.17:6438 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:26472 pid:6438 tgid:6438 ppid:6338 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 io_schedule+0x80/0xd0 kernel/sched/core.c:7871 folio_wait_bit_common+0x6b0/0xb80 mm/filemap.c:1335 folio_lock include/linux/pagemap.h:1149 [inline] writeback_get_folio mm/page-writeback.c:2468 [inline] writeback_iter+0x8d8/0x12a0 mm/page-writeback.c:2562 iomap_writepages+0x14d/0x2d0 fs/iomap/buffered-io.c:1769 gfs2_writepages+0x177/0x250 fs/gfs2/aops.c:175 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] __filemap_fdatawrite_range mm/filemap.c:422 [inline] __filemap_fdatawrite mm/filemap.c:428 [inline] filemap_fdatawrite+0x199/0x240 mm/filemap.c:433 gfs2_ordered_write fs/gfs2/log.c:729 [inline] gfs2_log_flush+0x86b/0x24c0 fs/gfs2/log.c:1092 gfs2_trans_end+0x37c/0x570 fs/gfs2/trans.c:158 gfs2_page_mkwrite+0x14a8/0x1910 fs/gfs2/file.c:535 do_page_mkwrite+0x14d/0x310 mm/memory.c:3532 do_shared_fault mm/memory.c:5818 [inline] do_fault mm/memory.c:5880 [inline] do_pte_missing mm/memory.c:4405 [inline] handle_pte_fault mm/memory.c:6221 [inline] __handle_mm_fault+0x1911/0x5440 mm/memory.c:6363 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6532 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7faa5ae550b3 RSP: 002b:00007ffc4780dc70 EFLAGS: 00010246 RAX: 0000200000000180 RBX: 0000000000000008 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055557d7db3c8 RBP: 00007ffc4780dd78 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00007faa5b1b5fac R13: 00007faa5b1b5fa0 R14: fffffffffffffffe R15: 00007ffc4780ddc0 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/36: #0: ffff88801e6ae148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801e6ae148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000ac7ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000ac7ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88807e5140e0 (&type->s_umount_key#53){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88805faecea0 (&sdp->sd_log_flush_lock){++++}-{4:4}, at: gfs2_log_flush+0xec/0x24c0 fs/gfs2/log.c:1035 2 locks held by getty/5588: #0: ffff88803029c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz.0.17/6438: #0: ffff88807d1b4948 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1a3/0x450 mm/mmap_lock.c:238 #1: ffff88807e514518 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x14d/0x310 mm/memory.c:3532 #2: ffff88807e514610 (sb_internal#2){.+.+}-{0:0}, at: gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:118 #3: ffff88805faecea0 (&sdp->sd_log_flush_lock){++++}-{4:4}, at: gfs2_log_flush+0xec/0x24c0 fs/gfs2/log.c:1035 1 lock held by gfs2_logd/syz:s/6442: #0: ffff88805faecea0 (&sdp->sd_log_flush_lock){++++}-{4:4}, at: gfs2_log_flush+0xec/0x24c0 fs/gfs2/log.c:1035 4 locks held by syz.1.211/7249: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:337 [inline] watchdog+0xfa9/0xff0 kernel/hung_task.c:500 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: 0x0 (events_unbound) RIP: 0010:check_preemption_disabled+0x49/0x120 lib/smp_processor_id.c:53 Code: 8b 0d db 64 43 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d bb 64 43 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> c3 cc cc cc cc cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 RSP: 0000:ffffc90000127850 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 49c617a174917a00 RDX: 0000000000000000 RSI: ffffffff8bc07cc0 RDI: ffffffff8bc07c80 RBP: ffffc900001279f0 R08: ffffffff8f9e3177 R09: 1ffffffff1f3c62e R10: dffffc0000000000 R11: fffffbfff1f3c62f R12: ffff88801ce80000 R13: 0000000000000000 R14: ffffffff8da10dd8 R15: 1ffff92000024f2c FS: 0000000000000000(0000) GS:ffff888125e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbbdf26c000 CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching kernel/rcu/tree.c:751 [inline] trace_rcu_utilization+0x47/0x1d0 include/trace/events/rcu.h:27 rcu_note_context_switch+0xc9/0x1140 kernel/rcu/tree_plugin.h:330 __schedule+0x35d/0x4cc0 kernel/sched/core.c:6814 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 worker_thread+0xa82/0xda0 kernel/workqueue.c:3442 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245