INFO: task syz.3.17:2919 blocked for more than 143 seconds. Not tainted 6.13.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.17 state:D stack:13040 pid:2919 tgid:2918 ppid:2464 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x68f/0xa80 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xac/0x140 kernel/sched/core.c:6848 io_schedule+0x3f/0x60 kernel/sched/core.c:7681 folio_wait_bit_common+0x1e5/0x490 mm/filemap.c:1308 folio_wait_writeback+0x2c/0x110 mm/page-writeback.c:3194 __filemap_fdatawait_range mm/filemap.c:532 [inline] file_write_and_wait_range+0x1ac/0x1d0 mm/filemap.c:791 v9fs_file_fsync+0x2b/0x110 fs/9p/vfs_file.c:418 generic_write_sync include/linux/fs.h:2919 [inline] netfs_file_write_iter+0xc5/0x100 fs/netfs/buffered_write.c:487 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x3cd/0x4b0 fs/read_write.c:679 ksys_write+0x75/0xf0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x8f/0x180 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f82a656ebe9 RSP: 002b:00007f82a63df038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f82a6795fa0 RCX: 00007f82a656ebe9 RDX: 0000000000007fec RSI: 0000200000000300 RDI: 0000000000000007 RBP: 00007f82a65f1e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f82a6796038 R14: 00007f82a6795fa0 R15: 00007fff02e33ca8 Showing all locks held in the system: 2 locks held by kworker/u8:0/11: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc90000063e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000063e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by kworker/u8:1/13: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc90000073e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000073e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 1 lock held by khungtaskd/30: #0: ffffffff82778b20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff82778b20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff82778b20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x2e/0x100 kernel/locking/lockdep.c:6744 2 locks held by kworker/u8:3/94: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc90000193e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000193e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by kworker/u8:4/254: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc90000e37e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000e37e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by getty/845: #0: ffff888100a8b8a0 (&tty->ldisc_sem){....}-{0:0}, at: tty_ldisc_ref_wait+0x20/0x40 drivers/tty/tty_ldisc.c:243 #1: ffffc900001fb2f0 (&ldata->atomic_read_lock){....}-{3:3}, at: n_tty_read+0x1bb/0x6e0 drivers/tty/n_tty.c:2211 2 locks held by syz.3.17/2919: #0: ffff88810d6f32f8 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff88810f6ff3f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by syz.4.18/3377: #0: ffff88810c7e95f8 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff888107adf3f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by kworker/u8:5/3379: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc90001d27e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90001d27e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by syz.5.19/3837: #0: ffff8881017f3bf8 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff8881046d13f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by kworker/u8:6/3838: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc900023e7e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900023e7e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by syz.6.20/4296: #0: ffff88810c7e9478 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff88810bbf53f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by syz.7.21/4755: #0: ffff88810c7e9a78 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff88810bbc53f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by kworker/u8:7/4757: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc900031a7e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900031a7e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by syz.8.22/5215: #0: ffff88810d6f3178 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff88810cfc53f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by kworker/u8:8/5217: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc90003997e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003997e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by kworker/u8:9/5218: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc9000389fe58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000389fe58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by syz.9.23/5676: #0: ffff88810d6f35f8 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff8881033bd3f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by syz.0.24/6136: #0: ffff88810d6fdbf8 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff888108f4a3f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by kworker/u8:11/6138: #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88810007c948 ((wq_completion)events_unbound){....}-{0:0}, at: process_scheduled_works+0x281/0x5e0 kernel/workqueue.c:3310 #1: ffffc90004747e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90004747e58 ((work_completion)(&rreq->work)){....}-{0:0}, at: process_scheduled_works+0x2a1/0x5e0 kernel/workqueue.c:3310 2 locks held by syz.1.25/6596: #0: ffff88810c7e98f8 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff88810a7c23f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 2 locks held by syz.2.26/7055: #0: ffff88810d6fd8f8 (&f->f_pos_lock){....}-{3:3}, at: fdget_pos+0x7f/0xb0 fs/file.c:1191 #1: ffff88810a7c63f8 (sb_writers#13){....}-{0:0}, at: ksys_write+0x75/0xf0 fs/read_write.c:731 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0xa4/0xf0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x10b/0x170 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x8e/0x140 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0x5ed/0x610 kernel/hung_task.c:397 kthread+0xe9/0x100 kernel/kthread.c:389 ret_from_fork+0x32/0x40 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7057 Comm: kworker/u8:12 Not tainted 6.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline] RIP: 0010:rcu_is_watching+0x20/0x40 kernel/rcu/tree.c:738 Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 ff 05 4d 36 ed 7e e8 c0 bd be 00 89 c0 48 8b 04 c5 50 d9 52 82 8b 80 10 9b 02 00 <65> ff 0d 31 36 ed 7e 74 0c 83 e0 04 c1 e8 02 c3 cc cc cc cc cc 0f RSP: 0018:ffffc90005487c68 EFLAGS: 00000082 RAX: 00000000000726cc RBX: ffff88810a740000 RCX: 86762aae5347ef00 RDX: 0000000000000000 RSI: ffffffff824552d9 RDI: ffffffff8251139e RBP: 0000000000000000 R08: 000ffffffffff000 R09: 0000000000000039 R10: 0000000000000006 R11: ffffffff81057400 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff827b1100 R15: ffff888100070000 FS: 0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556ee354a8 CR3: 000000010006a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_tlb_flush include/trace/events/tlb.h:38 [inline] switch_mm_irqs_off+0x426/0x670 arch/x86/mm/tlb.c:-1 use_temporary_mm arch/x86/kernel/alternative.c:1838 [inline] __text_poke+0x251/0x440 arch/x86/kernel/alternative.c:1949 text_poke arch/x86/kernel/alternative.c:2013 [inline] text_poke_bp_batch+0x233/0x2e0 arch/x86/kernel/alternative.c:2402 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked kernel/jump_label.c:210 [inline] static_key_enable+0x40/0x60 kernel/jump_label.c:223 toggle_allocation_gate+0x40/0x140 mm/kfence/core.c:849 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0x2e6/0x5e0 kernel/workqueue.c:3310 worker_thread+0x244/0x2f0 kernel/workqueue.c:3391 kthread+0xe9/0x100 kernel/kthread.c:389 ret_from_fork+0x32/0x40 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244