INFO: task kcompactd0:1661 blocked for more than 143 seconds. Not tainted 5.11.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kcompactd0 state:D stack:28104 pid: 1661 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4313 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5064 schedule+0xcf/0x270 kernel/sched/core.c:5143 io_schedule+0xba/0x130 kernel/sched/core.c:6838 wait_on_page_bit_common+0x424/0xeb0 mm/filemap.c:1273 lock_page include/linux/pagemap.h:611 [inline] __unmap_and_move mm/migrate.c:1043 [inline] unmap_and_move mm/migrate.c:1193 [inline] migrate_pages+0x97b/0x34a0 mm/migrate.c:1459 compact_zone+0x1ccd/0x3be0 mm/compaction.c:2357 kcompactd_do_work+0x2c9/0x730 mm/compaction.c:2767 kcompactd+0x25d/0xd00 mm/compaction.c:2862 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Showing all locks held in the system: 2 locks held by systemd/1: 1 lock held by khungtaskd/1655: #0: ffffffff8b373920 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by kswapd0/2193: 1 lock held by kswapd1/2194: 2 locks held by systemd-journal/4868: 1 lock held by systemd-udevd/4894: 2 locks held by systemd-timesyn/4981: 2 locks held by cron/8359: 2 locks held by in:imklog/8368: 4 locks held by syz-fuzzer/8485: 2 locks held by syz-fuzzer/8487: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1655 Comm: khungtaskd Not tainted 5.11.0-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:79 [inline] dump_stack+0x107/0x163 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+0xd43/0xfa0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8359 Comm: cron Not tainted 5.11.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode+0x0/0x40 kernel/kcov.c:163 Code: 48 8b 54 24 10 e9 c6 fe ff ff 48 89 df e8 98 c8 42 00 e9 a1 fe ff ff 48 8b 3c 24 e8 8a c8 42 00 e9 18 fe ff ff cc cc cc cc cc <65> 8b 05 c9 2d 8f 7e 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 RSP: 0018:ffffc90001aeefc8 EFLAGS: 00000046 RAX: 1ffffd40005595e0 RBX: ffffea0002acaf08 RCX: ffff888014dbd340 RDX: fffff940005595e1 RSI: ffff888014dbd340 RDI: 0000000000000003 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff819b9153 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffea0002acaf00 R15: dffffc0000000000 FS: 00007feefbf43840(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f879e485c0 CR3: 000000001a95c000 CR4: 0000000000350ee0 Call Trace: write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp1+0x22/0x80 kernel/kcov.c:270 page_lru include/linux/mm_inline.h:123 [inline] move_pages_to_lru+0x883/0x1a20 mm/vmscan.c:1877 shrink_inactive_list+0x365/0xca0 mm/vmscan.c:1961 shrink_list mm/vmscan.c:2180 [inline] shrink_lruvec+0x62c/0x11d0 mm/vmscan.c:2475 shrink_node_memcgs mm/vmscan.c:2663 [inline] shrink_node+0x863/0x1de0 mm/vmscan.c:2780 shrink_zones mm/vmscan.c:2983 [inline] do_try_to_free_pages+0x388/0x14b0 mm/vmscan.c:3038 try_to_free_pages+0x29f/0x720 mm/vmscan.c:3277 __perform_reclaim mm/page_alloc.c:4377 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4398 [inline] __alloc_pages_slowpath.constprop.0+0x88e/0x2240 mm/page_alloc.c:4802 __alloc_pages_nodemask+0x5f0/0x730 mm/page_alloc.c:5012 alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2267 alloc_pages include/linux/gfp.h:547 [inline] __page_cache_alloc mm/filemap.c:977 [inline] __page_cache_alloc+0x2ce/0x360 mm/filemap.c:962 pagecache_get_page+0x392/0x1460 mm/filemap.c:1837 filemap_fault+0x1a67/0x2af0 mm/filemap.c:2823 ext4_filemap_fault+0x87/0xc0 fs/ext4/inode.c:6205 __do_fault+0x10d/0x4d0 mm/memory.c:3625 do_read_fault mm/memory.c:4019 [inline] do_fault mm/memory.c:4147 [inline] handle_pte_fault mm/memory.c:4387 [inline] __handle_mm_fault mm/memory.c:4522 [inline] handle_mm_fault+0x3202/0x5690 mm/memory.c:4620 do_user_addr_fault+0x458/0xc60 arch/x86/mm/fault.c:1393 handle_page_fault arch/x86/mm/fault.c:1450 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1506 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580 RIP: 0033:0x7feefb60e270 Code: Unable to access opcode bytes at RIP 0x7feefb60e246. RSP: 002b:00007ffea62603a8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: fffffffffffffeb0 RCX: 00007feefb60e270 RDX: 00007ffea633f080 RSI: 00007ffea62603b0 RDI: 00007ffea62603b0 RBP: 0000000000000002 R08: 0000000000000010 R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffea6260500 R14: 0000000000000000 R15: 0000000000000000