INFO: task kcompactd0:1636 blocked for more than 143 seconds. Not tainted 5.13.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kcompactd0 state:D stack:28480 pid: 1636 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x916/0x23e0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 io_schedule+0xba/0x130 kernel/sched/core.c:7214 wait_on_page_bit_common+0x571/0xe90 mm/filemap.c:1301 lock_page include/linux/pagemap.h:625 [inline] __unmap_and_move mm/migrate.c:1024 [inline] unmap_and_move mm/migrate.c:1174 [inline] migrate_pages+0xa49/0x37d0 mm/migrate.c:1448 compact_zone+0x1ab6/0x3810 mm/compaction.c:2401 kcompactd_do_work+0x2c9/0x730 mm/compaction.c:2816 kcompactd+0x262/0xd10 mm/compaction.c:2911 kthread+0x3b1/0x4a0 kernel/kthread.c:313 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/u4:0/9: 3 locks held by kworker/u4:2/54: 1 lock held by khungtaskd/1618: #0: ffffffff8bf76c20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 1 lock held by khugepaged/1639: 1 lock held by kswapd0/2130: 3 locks held by kswapd1/2131: 2 locks held by systemd-journal/4834: 1 lock held by systemd-udevd/4850: 2 locks held by systemd-timesyn/4932: 2 locks held by cron/8340: 2 locks held by in:imklog/8349: 2 locks held by agetty/8354: #0: ffff88801cf34098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900016002e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xd5b/0x12f0 drivers/tty/n_tty.c:2179 4 locks held by syz-fuzzer/8445: 2 locks held by syz-fuzzer/8467: 3 locks held by kworker/u4:7/15540: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1618 Comm: khungtaskd Not tainted 5.13.0-rc6-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:313 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: 8445 Comm: syz-fuzzer Not tainted 5.13.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data kernel/kcov.c:218 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x15/0x80 kernel/kcov.c:270 Code: 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 00 f0 01 00 <48> 89 ce 4c 8b 54 24 08 e8 8e ef ff ff 84 c0 74 51 48 8b 81 20 15 RSP: 0018:ffffc90001016e48 EFLAGS: 00000046 RAX: 1ffffd40003cae70 RBX: ffffea0001e57388 RCX: ffff888023f06080 RDX: fffff940003cae71 RSI: 0000000000000000 RDI: 0000000000000003 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: fffff940003cae70 R11: 0000000000000000 R12: 0000000000000002 R13: ffffea0001e57380 R14: 0000000000000000 R15: 0000000000000000 FS: 000000c00002e490(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f49c8d489e0 CR3: 000000001d9f0000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: page_lru include/linux/mm_inline.h:76 [inline] add_page_to_lru_list include/linux/mm_inline.h:85 [inline] move_pages_to_lru+0x806/0x2110 mm/vmscan.c:2067 shrink_inactive_list+0x365/0xca0 mm/vmscan.c:2148 shrink_list mm/vmscan.c:2367 [inline] shrink_lruvec+0x7f9/0x14f0 mm/vmscan.c:2662 shrink_node_memcgs mm/vmscan.c:2850 [inline] shrink_node+0x868/0x1de0 mm/vmscan.c:2967 shrink_zones mm/vmscan.c:3170 [inline] do_try_to_free_pages+0x388/0x14b0 mm/vmscan.c:3225 try_to_free_pages+0x29f/0x750 mm/vmscan.c:3464 __perform_reclaim mm/page_alloc.c:4430 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4451 [inline] __alloc_pages_slowpath.constprop.0+0x84e/0x2140 mm/page_alloc.c:4855 __alloc_pages+0x422/0x500 mm/page_alloc.c:5213 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272 __page_cache_alloc mm/filemap.c:1005 [inline] __page_cache_alloc+0x303/0x3a0 mm/filemap.c:990 pagecache_get_page+0x38f/0x18d0 mm/filemap.c:1885 filemap_fault+0x166c/0x25b0 mm/filemap.c:2992 ext4_filemap_fault+0x87/0xc0 fs/ext4/inode.c:6194 __do_fault+0x10d/0x4d0 mm/memory.c:3721 do_read_fault mm/memory.c:4025 [inline] do_fault mm/memory.c:4153 [inline] handle_pte_fault mm/memory.c:4412 [inline] __handle_mm_fault+0x2c5f/0x52c0 mm/memory.c:4547 handle_mm_fault+0x1bc/0x7e0 mm/memory.c:4645 do_user_addr_fault+0x483/0x1210 arch/x86/mm/fault.c:1390 handle_page_fault arch/x86/mm/fault.c:1475 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577 RIP: 0033:0x414c65 Code: 00 00 00 00 00 48 39 c8 0f 84 af 00 00 00 80 3d f4 37 47 01 00 0f 84 98 00 00 00 48 8b 54 24 38 48 8b 5a 08 90 48 85 db 75 62 <48> 8b 1a 48 89 04 24 48 89 4c 24 08 48 89 5c 24 10 e8 45 84 05 00 RSP: 002b:000000c00003fc40 EFLAGS: 00010246 RAX: 000000c010608100 RBX: 0000000000000018 RCX: 000000c00003fd48 RDX: 0000000000771e40 RSI: c02c1c57dee3b88b RDI: 0000000000000001 RBP: 000000c00003fc68 R08: 00000000000001db R09: 00007ffedbb98080 R10: 00007ffedbb98090 R11: 0000000000016b9c R12: 0000006ebc9ef4ee R13: 0000000000000001 R14: 0000006ebc9ef4ee R15: 000000000000d8e2