INFO: task kcompactd0:31 blocked for more than 143 seconds. Not tainted 6.2.0-syzkaller-12018-g2fcd07b7ccd5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kcompactd0 state:D stack:25120 pid:31 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5304 [inline] __schedule+0x17d8/0x4990 kernel/sched/core.c:6622 schedule+0xc3/0x180 kernel/sched/core.c:6698 io_schedule+0x8c/0x100 kernel/sched/core.c:8884 folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301 migrate_folio_unmap mm/migrate.c:1171 [inline] migrate_pages_batch mm/migrate.c:1685 [inline] migrate_pages+0x2aa0/0x6610 mm/migrate.c:1973 compact_zone+0x2bc9/0x45a0 mm/compaction.c:2420 proactive_compact_node mm/compaction.c:2685 [inline] kcompactd+0x1165/0x1e80 mm/compaction.c:2993 kthread+0x270/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d127c70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d128470 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510 1 lock held by khungtaskd/28: #0: ffffffff8d127aa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/4746: #0: ffff88802c4c3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2177 1 lock held by syz-executor.4/5124: #0: ffffffff8d12d178 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline] #0: ffffffff8d12d178 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a3/0x890 kernel/rcu/tree_exp.h:989 2 locks held by kworker/0:4/5167: #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x77f/0x13a0 #1: ffffc90004567d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7c6/0x13a0 kernel/workqueue.c:2365 3 locks held by kworker/1:20/6702: #0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x77f/0x13a0 #1: ffffc9000481fd20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7c6/0x13a0 kernel/workqueue.c:2365 #2: ffffffff8d12d178 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:325 [inline] #2: ffffffff8d12d178 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x46c/0x890 kernel/rcu/tree_exp.h:989 1 lock held by syz-executor.5/15280: 2 locks held by syz-executor.3/17271: 2 locks held by syz-executor.5/17272: 1 lock held by syz-executor.0/17270: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.2.0-syzkaller-12018-g2fcd07b7ccd5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e5/0x560 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1b4/0x410 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0x1024/0x1070 kernel/hung_task.c:379 kthread+0x270/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5730 Comm: syz-fuzzer Not tainted 6.2.0-syzkaller-12018-g2fcd07b7ccd5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 RIP: 0033:0x4664b6 Code: fe ff ff c5 fd ef c0 48 81 fb 00 00 00 02 73 46 c5 fe 7f 07 c5 fe 7f 47 20 c5 fe 7f 47 40 c5 fe 7f 47 60 48 81 eb 80 00 00 00 <48> 81 c7 80 00 00 00 48 81 fb 80 00 00 00 73 d6 c5 fe 7f 44 1f e0 RSP: 002b:000000c000c85370 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000025080 RCX: 0000000000026000 RDX: 0000000000000001 RSI: 0000000000040000 RDI: 000000c01c100f00 RBP: 000000c000c85398 R08: 0000000000000020 R09: 0000000000000000 R10: 000000000000005e R11: 0000000000000001 R12: 8ff7da18fe3ca503 R13: 0000000000000000 R14: 000000c000448000 R15: 0000000000000000 FS: 000000c027c50490 GS: 0000000000000000