INFO: task kcompactd0:1633 blocked for more than 143 seconds. Not tainted 5.12.0-rc8-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kcompactd0 state:D stack:28024 pid: 1633 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x911/0x21b0 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 io_schedule+0xba/0x130 kernel/sched/core.c:7209 wait_on_page_bit_common+0x571/0xe90 mm/filemap.c:1274 lock_page include/linux/pagemap.h:610 [inline] __unmap_and_move mm/migrate.c:1050 [inline] unmap_and_move mm/migrate.c:1200 [inline] migrate_pages+0x98a/0x35d0 mm/migrate.c:1472 compact_zone+0x1abd/0x3820 mm/compaction.c:2365 kcompactd_do_work+0x2c9/0x730 mm/compaction.c:2775 kcompactd+0x262/0xd10 mm/compaction.c:2870 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Showing all locks held in the system: 1 lock held by systemd/1: 3 locks held by kworker/u4:1/25: 1 lock held by khungtaskd/1629: #0: ffffffff8bf74360 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6328 1 lock held by kswapd0/2126: 1 lock held by kswapd1/2127: 1 lock held by systemd-journal/4823: 2 locks held by systemd-udevd/4833: 1 lock held by cron/8077: 2 locks held by in:imklog/8108: 4 locks held by rs:main Q:Reg/8109: 2 locks held by agetty/8112: #0: ffff888019a8b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc900011a82e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xd5b/0x12f0 drivers/tty/n_tty.c:2178 2 locks held by syz-fuzzer/8384: 2 locks held by agetty/10471: #0: ffff888030180098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc90000f5c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xd5b/0x12f0 drivers/tty/n_tty.c:2178 2 locks held by syz-executor.3/18934: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1629 Comm: khungtaskd Not tainted 5.12.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd48/0xfb0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2126 Comm: kswapd0 Not tainted 5.12.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hlock_class kernel/locking/lockdep.c:198 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4575 [inline] RIP: 0010:__lock_acquire+0x47a/0x54c0 kernel/locking/lockdep.c:4851 Code: 41 81 e5 ff 1f 45 0f b7 ed be 08 00 00 00 4c 89 e8 48 c1 f8 06 48 8d 3c c5 a0 a8 a9 8f e8 ce 6d 5e 00 4c 0f a3 2d d6 63 50 0e <0f> 83 a7 0b 00 00 4b 8d 44 6d 00 48 c1 e0 06 48 05 c0 ac a9 8f 48 RSP: 0018:ffffc90007767380 EFLAGS: 00000047 RAX: 0000000000000001 RBX: ffff888017b15eb0 RCX: ffffffff815944c2 RDX: fffffbfff1f53515 RSI: 0000000000000008 RDI: ffffffff8fa9a8a0 RBP: ffff888017b15f00 R08: 0000000000000000 R09: ffffffff8fa9a8a7 R10: fffffbfff1f53514 R11: 0000000000000000 R12: ffff888017b154c0 R13: 000000000000002b R14: 0000000000000002 R15: 0000000000020000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8e1668d1d0 CR3: 0000000012c53000 CR4: 0000000000350ef0 Call Trace: lock_acquire kernel/locking/lockdep.c:5511 [inline] lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5476 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:656 [inline] page_evictable+0x38/0x340 mm/internal.h:83 move_pages_to_lru+0x2ba/0x2370 mm/vmscan.c:1832 shrink_inactive_list+0x365/0xca0 mm/vmscan.c:1951 shrink_list mm/vmscan.c:2170 [inline] shrink_lruvec+0x7f9/0x14f0 mm/vmscan.c:2465 shrink_node_memcgs mm/vmscan.c:2653 [inline] shrink_node+0x868/0x1de0 mm/vmscan.c:2770 kswapd_shrink_node mm/vmscan.c:3513 [inline] balance_pgdat+0x745/0x1270 mm/vmscan.c:3671 kswapd+0x5b6/0xdb0 mm/vmscan.c:3928 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294