INFO: task kcompactd0:31 blocked for more than 143 seconds. Not tainted 6.4.0-rc7-syzkaller-00226-ga92b7d26c743 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kcompactd0 state:D stack:24544 pid:31 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 io_schedule+0x8c/0x100 kernel/sched/core.c:8979 folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301 migrate_folio_unmap mm/migrate.c:1159 [inline] migrate_pages_batch+0x8c9/0x3670 mm/migrate.c:1674 migrate_pages_sync mm/migrate.c:1889 [inline] migrate_pages+0x27ce/0x35d0 mm/migrate.c:1970 compact_zone+0x2ac4/0x4040 mm/compaction.c:2439 kcompactd_do_work mm/compaction.c:2882 [inline] kcompactd+0xc8c/0x1ba0 mm/compaction.c:2981 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cf276f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cf27ab0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8cf27520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kswapd0/83: 2 locks held by getty/4747: #0: ffff88802894e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176 2 locks held by kworker/u4:0/20034: 1 lock held by syz-executor.3/20206: 1 lock held by syz-executor.3/20343: 1 lock held by syz-executor.3/20401: 1 lock held by syz-executor.3/20462: 1 lock held by syz-executor.3/20524: 1 lock held by syz-executor.3/20589: 1 lock held by syz-executor.3/20929: 1 lock held by syz-executor.3/21152: 1 lock held by syz-executor.3/21235: 1 lock held by syz-executor.3/21293: 1 lock held by syz-executor.5/8727: 1 lock held by syz-executor.5/9063: 1 lock held by syz-executor.5/9158: 1 lock held by syz-executor.3/9174: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc7-syzkaller-00226-ga92b7d26c743 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x187/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xec2/0xf00 kernel/hung_task.c:379 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4431 Comm: syslogd Not tainted 6.4.0-rc7-syzkaller-00226-ga92b7d26c743 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 RIP: 0010:deref_stack_reg+0x199/0x210 arch/x86/kernel/unwind_orc.c:378 Code: 77 2e 4c 89 c7 48 89 d3 e8 b4 07 00 00 49 89 c6 48 8b 6c 24 18 48 89 e8 48 c1 e8 03 80 3c 18 00 74 08 48 89 ef e8 07 89 a6 00 <4c> 89 75 00 b0 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 44 RSP: 0018:ffffc9000316f358 EFLAGS: 00000246 RAX: 1ffff9200062de98 RBX: dffffc0000000000 RCX: ffffffff8edc7a8d RDX: dffffc0000000000 RSI: ffffc90003168000 RDI: ffffc9000316f878 RBP: ffffc9000316f4c0 R08: ffffc9000316f878 R09: 0000000000000000 R10: ffffc9000316f4d0 R11: dffffc0000000001 R12: 1ffff9200062de91 R13: 1ffff9200062de92 R14: 0000000000000000 R15: ffffc90003170000 FS: 00007f4332c99380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbe11d88218 CR3: 000000002cc36000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x18dc/0x2200 arch_stack_walk+0x111/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x117/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:521 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook mm/slub.c:1807 [inline] slab_free mm/slub.c:3786 [inline] __kmem_cache_free+0x264/0x3c0 mm/slub.c:3799 skb_kfree_head net/core/skbuff.c:906 [inline] skb_free_head net/core/skbuff.c:918 [inline] skb_release_data+0x660/0x850 net/core/skbuff.c:948 skb_release_all net/core/skbuff.c:1014 [inline] __kfree_skb net/core/skbuff.c:1028 [inline] consume_skb+0xb3/0x150 net/core/skbuff.c:1244 __unix_dgram_recvmsg+0xcb7/0x1260 net/unix/af_unix.c:2532 sock_recvmsg_nosec net/socket.c:1019 [inline] sock_recvmsg net/socket.c:1040 [inline] sock_read_iter+0x3a8/0x500 net/socket.c:1118 call_read_iter include/linux/fs.h:1862 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x788/0xb00 fs/read_write.c:470 ksys_read+0x1a0/0x2c0 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4332dedb6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd8ead30b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f4332dedb6a RDX: 00000000000000ff RSI: 000055e0dffef950 RDI: 0000000000000000 RBP: 000055e0dffef910 R08: 0000000000000001 R09: 0000000000000000 R10: 00007f4332f8c3a3 R11: 0000000000000246 R12: 000055e0dffef99d R13: 000055e0dffef950 R14: 0000000000000000 R15: 00007f4332fcaa80