INFO: task syz.4.13805:8952 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.13805 state:D stack:26992 pid: 8952 ppid: 4199 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127 _free_event+0x34/0xe60 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x626/0x20c0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fb2d80dce59 RSP: 002b:00007fb2d6336028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: 0000000000000012 RBX: 00007fb2d8355fa0 RCX: 00007fb2d80dce59 RDX: 0000000000000012 RSI: 0000200000000080 RDI: 000000000000000c RBP: 00007fb2d8172d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb2d8356038 R14: 00007fb2d8355fa0 R15: 00007ffc05b4c0f8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3948: #0: ffff88802c597098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 1 lock held by syz.6.14229/10805: 3 locks held by syz.5.14230/10820: 2 locks held by syz.5.14245/10841: 2 locks held by syz.1.14241/10862: 2 locks held by syz.6.14247/10879: 2 locks held by syz.5.14255/10924: 2 locks held by syz.3.14263/10957: 2 locks held by syz.6.14277/10960: 2 locks held by syz.1.14273/10988: 3 locks held by syz.6.14282/11022: 2 locks held by syz.5.14284/11027: #0: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 #1: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 2 locks held by syz.1.14283/11028: 1 lock held by syz.6.14285/11031: #0: ffff88802e322c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #0: ffff88802e322c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline] #0: ffff88802e322c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345 1 lock held by dhcpcd/11042: #0: ffff888056c38120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff888056c38120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3213 2 locks held by syz.1.14287/11045: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 30 Comm: kcompactd0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x80 kernel/kcov.c:301 Code: 28 4d 39 ca 77 22 89 ff 89 f6 4a c7 44 02 08 05 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 <48> 8b 04 24 65 48 8b 0d 44 37 89 7e 65 8b 15 45 37 89 7e 81 e2 00 RSP: 0018:ffffc90000e5f420 EFLAGS: 00000246 RAX: 1ffffd400035a53b RBX: ffff88801be50fc0 RCX: ffff888017a55940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 1ffffd400035a539 R08: ffffea0001ad29c7 R09: 1ffffd400035a538 R10: dffffc0000000000 R11: fffff9400035a539 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000080000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcf4736f32 CR3: 0000000073706000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: page_mapping+0x300/0x440 mm/util.c:810 move_to_new_page+0x2f4/0xe60 mm/migrate.c:896 __unmap_and_move mm/migrate.c:1077 [inline] unmap_and_move mm/migrate.c:1218 [inline] migrate_pages+0x1a7a/0x31a0 mm/migrate.c:1493 compact_zone+0x2864/0x3ed0 mm/compaction.c:2424 proactive_compact_node mm/compaction.c:2673 [inline] kcompactd+0x148f/0x2080 mm/compaction.c:2983 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287