INFO: task kcompactd0:30 blocked for more than 143 seconds. Not tainted 5.15.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kcompactd0 state:D stack:27856 pid: 30 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: 3 locks held by kworker/0:1/7: 2 locks held by kworker/u4:1/10: #0: ffff8880b9c31a58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:474 [inline] #0: ffff8880b9c31a58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1317 [inline] #0: ffff8880b9c31a58 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1620 [inline] #0: ffff8880b9c31a58 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x236/0x26f0 kernel/sched/core.c:6201 #1: ffff8880b9c1f9c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39d/0x480 kernel/sched/psi.c:880 5 locks held by kworker/1:1/25: 1 lock held by khungtaskd/27: #0: ffffffff8b97fe60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by khugepaged/33: 1 lock held by kswapd0/263: 1 lock held by kswapd1/264: 1 lock held by systemd-journal/2957: 5 locks held by systemd-udevd/2969: 1 lock held by systemd-timesyn/3053: 1 lock held by cron/6226: 1 lock held by in:imklog/6238: 2 locks held by syz-fuzzer/18724: 3 locks held by systemd-udevd/9456: #0: ffff88807e7c6460 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:647 #1: ffff88814f9ce5f8 (&sb->s_type->i_mutex_key#8){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:786 [inline] #1: ffff88814f9ce5f8 (&sb->s_type->i_mutex_key#8){+.+.}-{3:3}, at: generic_file_write_iter+0x8a/0x220 mm/filemap.c:3926 #2: ffffffff8baa2608 (pcpu_drain_mutex){+.+.}-{3:3}, at: __drain_all_pages+0x4f/0x6c0 mm/page_alloc.c:3187 3 locks held by systemd-udevd/9485: 3 locks held by systemd-udevd/9975: 3 locks held by kworker/u4:0/20746: 1 lock held by syz-executor.5/366: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc2-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: 9975 Comm: systemd-udevd Not tainted 5.15.0-rc2-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:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197 Code: 01 f0 4d 89 03 e9 63 fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 <65> 8b 05 19 e4 8b 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc9001648ee30 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000200 RDX: 0000000000000000 RSI: ffff88806ef78000 RDI: 0000000000000003 RBP: 0000000000000200 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81d9ca23 R11: 0000000000000000 R12: ffff8880b9d2cb60 R13: ffff8880b9d2cb88 R14: ffff88806ef78000 R15: 0000000000000002 FS: 00007f4f6c6858c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f29b541c22d CR3: 000000007a697000 CR4: 0000000000350ee0 Call Trace: invalidate_bh_lrus_cpu+0xf8/0x140 fs/buffer.c:1432 lru_add_drain+0x108/0x430 mm/swap.c:702 shrink_inactive_list mm/vmscan.c:2262 [inline] shrink_list mm/vmscan.c:2508 [inline] shrink_lruvec+0xa06/0x25b0 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_vma+0xf3/0x7d0 mm/mempolicy.c:2158 shmem_alloc_page+0x11f/0x1f0 mm/shmem.c:1581 shmem_alloc_and_acct_page+0x161/0x8c0 mm/shmem.c:1606 shmem_getpage_gfp+0x687/0x25e0 mm/shmem.c:1901 shmem_getpage mm/shmem.c:151 [inline] shmem_write_begin+0xff/0x1e0 mm/shmem.c:2469 generic_perform_write+0x202/0x510 mm/filemap.c:3770 __generic_file_write_iter+0x24e/0x640 mm/filemap.c:3897 generic_file_write_iter+0xd7/0x220 mm/filemap.c:3929 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x429/0x660 fs/read_write.c:507 vfs_write+0x7cf/0xae0 fs/read_write.c:594 ksys_write+0x12d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4f6b4f7970 Code: Unable to access opcode bytes at RIP 0x7f4f6b4f7946. RSP: 002b:00007ffdea22e668 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000037 RCX: 00007f4f6b4f7970 RDX: 0000000000000037 RSI: 000055bde1aeee70 RDI: 000000000000000f RBP: 000055bde1aeee70 R08: 000055bde1acbca0 R09: 00007f4f6c6858c0 R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000037 R13: 0000000000000001 R14: 000055bde1acbbc0 R15: 0000000000000037 ---------------- Code disassembly (best guess): 0: 01 f0 add %esi,%eax 2: 4d 89 03 mov %r8,(%r11) 5: e9 63 fd ff ff jmpq 0xfffffd6d a: b9 ff ff ff ff mov $0xffffffff,%ecx f: ba 08 00 00 00 mov $0x8,%edx 14: 4d 8b 03 mov (%r11),%r8 17: 48 0f bd ca bsr %rdx,%rcx 1b: 49 8b 45 00 mov 0x0(%r13),%rax 1f: 48 63 c9 movslq %ecx,%rcx 22: e9 64 ff ff ff jmpq 0xffffff8b 27: 0f 1f 00 nopl (%rax) * 2a: 65 8b 05 19 e4 8b 7e mov %gs:0x7e8be419(%rip),%eax # 0x7e8be44a <-- trapping instruction 31: 89 c1 mov %eax,%ecx 33: 48 8b 34 24 mov (%rsp),%rsi 37: 81 e1 00 01 00 00 and $0x100,%ecx 3d: 65 gs 3e: 48 rex.W 3f: 8b .byte 0x8b