INFO: task syz.6.1585:10389 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1585 state:D stack:24592 pid:10389 ppid:4987 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 wb_wait_for_completion+0x16f/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x1c5/0xa10 fs/fs-writeback.c:2756 sync_filesystem+0x16d/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x471/0x4f0 fs/namespace.c:1191 task_work_run+0x1d0/0x260 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x9d5/0x2570 kernel/exit.c:881 do_group_exit+0x229/0x2e0 kernel/exit.c:1024 get_signal+0x1259/0x1340 kernel/signal.c:2872 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f089ad5e6ce RSP: 002b:00007f089bc31f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f089bc326c0 RCX: 00007f089ad5e6ce RDX: 00007f089bc31fb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f089ae33eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f089b026038 R14: 00007f089b025fa0 R15: 00007ffd35c76da8 Showing all locks held in the system: 2 locks held by kworker/u4:0/9: #0: ffff888019e5e138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc900000e7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527 2 locks held by getty/4028: #0: ffff88802fef9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 3 locks held by kworker/0:8/4318: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90004517d00 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962 3 locks held by kworker/1:5/4320: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90004547d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962 2 locks held by kworker/0:9/4348: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc900042d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 1 lock held by dhcpcd/6506: #0: ffff8880752dfa10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff8880752dfa10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff8880752dfa10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1400 2 locks held by syz.6.1585/10389: #0: ffff888068aa20e0 (&type->s_umount_key#117){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff888142f467d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888142f467d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a9/0xa10 fs/fs-writeback.c:2754 1 lock held by segctord/10619: 1 lock held by syz.2.2640/14179: 1 lock held by dhcpcd/14284: #0: ffff88807ba36130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff88807ba36130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3255 1 lock held by dhcpcd/14285: #0: ffff88807e0c6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff88807e0c6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3255 1 lock held by dhcpcd/14286: #0: ffff888079d4a130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff888079d4a130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3255 1 lock held by dhcpcd/14287: #0: ffff888069d2c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff888069d2c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3255 1 lock held by dhcpcd/14288: #0: ffff888079d48130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff888079d48130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3255 1 lock held by dhcpcd/14289: #0: ffff88807d544130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff88807d544130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3255 2 locks held by sed/14298: ============================================= 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 06/25/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 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: 14298 Comm: sed Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:filter_irq_stacks+0x66/0x90 kernel/stacktrace.c:395 Code: 48 3d e0 01 40 8a 0f 93 c1 48 3d 10 0f 40 8a 0f 92 c2 84 d1 75 27 48 3d 00 00 60 8a 0f 92 c1 48 3d 07 00 60 8a 0f 93 c0 08 c8 <74> 11 48 ff c3 49 83 c7 08 49 39 dc 75 ae 44 89 e3 eb 06 ff c3 eb RSP: 0000:ffffc90003a37708 EFLAGS: 00000202 RAX: ffffffff8a304901 RBX: 0000000000000007 RCX: 0000000000140d01 RDX: 0000000000000001 RSI: 0000000000000009 RDI: ffffc90003a377e0 RBP: ffffc90003a378e0 R08: 0000000000000001 R09: 1ffffffff1c42435 R10: dffffc0000000000 R11: fffffbfff1c42436 R12: 0000000000000009 R13: dffffc0000000000 R14: ffffc90003a377e0 R15: ffffc90003a37818 FS: 00007f07ee8cbc80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c71050b3d8 CR3: 0000000066a80000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __stack_depot_save+0x35/0x480 lib/stackdepot.c:439 save_stack+0x12f/0x230 mm/page_owner.c:128 __set_page_owner+0x19/0x60 mm/page_owner.c:190 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 __folio_alloc+0xe/0x30 mm/page_alloc.c:5690 vma_alloc_folio+0x499/0x900 mm/mempolicy.c:2243 alloc_page_vma include/linux/gfp.h:284 [inline] do_anonymous_page mm/memory.c:4189 [inline] handle_pte_fault mm/memory.c:5027 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1fe3/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f07eea2cd34 Code: 8d 34 19 49 39 d0 49 89 70 60 0f 95 c2 48 29 d8 48 83 c1 10 0f b6 d2 48 83 c8 01 48 c1 e2 02 48 09 da 48 83 ca 01 48 89 51 f8 <48> 89 46 08 48 89 cf 4c 89 e6 48 89 4c 24 08 e8 18 c7 ff ff 48 8b RSP: 002b:00007ffe6e9c60c0 EFLAGS: 00010206 RAX: 000000000001dc31 RBX: 0000000000001010 RCX: 000055c71050a3d0 RDX: 0000000000001011 RSI: 000055c71050b3d0 RDI: 0000000000000000 RBP: ffffffffffffffc0 R08: 00007f07eeb65ac0 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000297 R12: 0000000000001000 R13: 0000000000000000 R14: 00000000000000ff R15: 00007f07eeb65b20