INFO: task kcompactd0:29 blocked for more than 143 seconds. Not tainted 5.15.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kcompactd0 state:D stack:27848 pid: 29 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 io_schedule+0xba/0x130 kernel/sched/core.c:8389 wait_on_page_bit_common+0x537/0xe60 mm/filemap.c:1356 lock_page include/linux/pagemap.h:625 [inline] __unmap_and_move mm/migrate.c:987 [inline] unmap_and_move mm/migrate.c:1211 [inline] migrate_pages+0xa6d/0x39e0 mm/migrate.c:1488 compact_zone+0x1abb/0x3860 mm/compaction.c:2393 kcompactd_do_work+0x2c9/0x730 mm/compaction.c:2833 kcompactd+0x86d/0xf30 mm/compaction.c:2935 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 9 locks held by kworker/0:0/5: 1 lock held by khungtaskd/26: #0: ffffffff8b97d3e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by khugepaged/33: #0: ffffffff8ba5e688 (lock#5){+.+.}-{3:3}, at: __lru_add_drain_all+0x65/0x760 mm/swap.c:782 1 lock held by kswapd0/262: 1 lock held by kswapd1/263: 2 locks held by systemd-journal/2964: 1 lock held by cron/6441: 1 lock held by in:imklog/6450: #0: ffff888020956630 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by agetty/6456: #0: ffff8880127b9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc900015002e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 2 locks held by syz-fuzzer/6542: 2 locks held by syz-fuzzer/6543: 3 locks held by kworker/1:4/8143: 1 lock held by syz-executor.4/5899: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.15.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8143 Comm: kworker/1:4 Not tainted 5.15.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events fill_page_cache_func RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3683 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3702 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3757 [inline] RIP: 0010:__lock_acquire+0x16ab/0x54a0 kernel/locking/lockdep.c:5015 Code: db 74 58 48 83 eb 08 74 52 48 ba 00 00 00 00 00 fc ff df eb 06 48 83 eb 08 74 40 48 8d 7b 18 48 89 f8 48 c1 e8 03 80 3c 10 00 <0f> 85 31 2a 00 00 48 8b 43 18 49 39 c7 0f 84 ec f5 ff ff 48 8d 7b RSP: 0018:ffffc9001681ef00 EFLAGS: 00000046 RAX: 1ffffffff1e488f3 RBX: ffffffff8f244780 RCX: ffffffff815a378f RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8f244798 RBP: 000000000000ea63 R08: 0000000000000000 R09: ffffffff8fd01927 R10: fffffbfff1fa0324 R11: 0000000000000000 R12: ffff888089546c70 R13: ffff888089546200 R14: 0000000000000000 R15: 4be1819b21c8808c FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcf28042990 CR3: 0000000021331000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] free_unref_page_list+0x2e0/0xfa0 mm/page_alloc.c:3450 shrink_page_list+0x3fc3/0x6bf0 mm/vmscan.c:1811 shrink_inactive_list mm/vmscan.c:2281 [inline] shrink_list mm/vmscan.c:2508 [inline] shrink_lruvec+0xbaf/0x25b0 mm/vmscan.c:2827 shrink_node_memcgs mm/vmscan.c:3016 [inline] shrink_node+0x858/0x1eb0 mm/vmscan.c:3139 shrink_zones mm/vmscan.c:3342 [inline] do_try_to_free_pages+0x386/0x1480 mm/vmscan.c:3397 try_to_free_pages+0x29f/0x750 mm/vmscan.c:3632 __perform_reclaim mm/page_alloc.c:4592 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4613 [inline] __alloc_pages_slowpath.constprop.0+0x828/0x21b0 mm/page_alloc.c:5017 __alloc_pages+0x412/0x500 mm/page_alloc.c:5388 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2197 __get_free_pages+0x8/0x40 mm/page_alloc.c:5412 fill_page_cache_func+0xad/0x240 kernel/rcu/tree.c:3414 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: db 74 58 48 (bad) 0x48(%rax,%rbx,2) 4: 83 eb 08 sub $0x8,%ebx 7: 74 52 je 0x5b 9: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 10: fc ff df 13: eb 06 jmp 0x1b 15: 48 83 eb 08 sub $0x8,%rbx 19: 74 40 je 0x5b 1b: 48 8d 7b 18 lea 0x18(%rbx),%rdi 1f: 48 89 f8 mov %rdi,%rax 22: 48 c1 e8 03 shr $0x3,%rax 26: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) * 2a: 0f 85 31 2a 00 00 jne 0x2a61 <-- trapping instruction 30: 48 8b 43 18 mov 0x18(%rbx),%rax 34: 49 39 c7 cmp %rax,%r15 37: 0f 84 ec f5 ff ff je 0xfffff629 3d: 48 rex.W 3e: 8d .byte 0x8d 3f: 7b .byte 0x7b