INFO: task syz-executor:5907 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20504 pid:5907 tgid:5907 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 netfs_wait_for_outstanding_io include/linux/netfs.h:552 [inline] v9fs_evict_inode+0x170/0x320 fs/9p/vfs_inode.c:348 evict+0x504/0x9c0 fs/inode.c:810 dispose_list fs/inode.c:852 [inline] evict_inodes+0x64c/0x6d0 fs/inode.c:906 generic_shutdown_super+0x9a/0x2c0 fs/super.c:627 kill_anon_super+0x3b/0x70 fs/super.c:1281 v9fs_kill_super+0x4c/0x90 fs/9p/vfs_super.c:195 deactivate_locked_super+0xbc/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe96f58fed7 RSP: 002b:00007ffef7dd1dc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fe96f611c05 RCX: 00007fe96f58fed7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffef7dd1e80 RBP: 00007ffef7dd1e80 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffef7dd2f10 R13: 00007fe96f611c05 R14: 000000000006f794 R15: 00007ffef7dd2f50 Showing all locks held in the system: 3 locks held by kworker/0:0/9: 1 lock held by khungtaskd/31: #0: ffffffff8e53d360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53d360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53d360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by syslogd/5216: #0: ffff8880b863a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 #1: ffff8880b8624048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 2 locks held by getty/5628: #0: ffff88814dda60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5907: #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 5 locks held by kworker/0:4/5960: #0: ffff888143e8dd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888143e8dd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004a7fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004a7fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8881457d9198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff8881457d9198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff88807c142198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff88807c142198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #4: ffff888079bb6160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff888079bb6160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 1 lock held by syz.1.720/8552: #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.6.1121/9969: #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.0.1213/10231: #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888023e4a0e0 (&type->s_umount_key#81){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 3 locks held by syz.8.1325/10722: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10722 Comm: syz.8.1325 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:751 Code: e8 0b 73 e5 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 3d ed 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 cc f6 7d 00 48 c7 c3 d8 6f e9 92 49 03 1e 48 89 RSP: 0018:ffffc90004bee3d8 EFLAGS: 00000246 RAX: 1ffffffff1bda7bb RBX: 0000000000000001 RCX: 7c8990ec38c6d800 RDX: 0000000000000000 RSI: ffffffff8c050ee0 RDI: ffffffff8c050ea0 RBP: ffffffff8216c1bd R08: 0000000000000001 R09: 0000000000000000 R10: ffffc90004bee560 R11: fffff5200097dcb1 R12: 0000000000000000 R13: ffffffff8e6569e0 R14: ffffffff8ded3dd8 R15: dffffc0000000000 FS: 00007f308deef6c0(0000) GS:ffff88812589c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c359825 CR3: 0000000078770000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831 fs_reclaim_acquire+0x99/0x100 mm/page_alloc.c:4262 might_alloc include/linux/sched/mm.h:318 [inline] prepare_alloc_pages+0x153/0x610 mm/page_alloc.c:4927 __alloc_frozen_pages_noprof+0x123/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2517 filemap_alloc_folio_noprof+0xdf/0x470 mm/filemap.c:1020 __filemap_get_folio+0x3f2/0xaf0 mm/filemap.c:1994 simple_write_begin+0x61/0x500 fs/libfs.c:930 generic_perform_write+0x2c5/0x900 mm/filemap.c:4209 generic_file_write_iter+0x117/0x550 mm/filemap.c:4352 __kernel_write_iter+0x428/0x910 fs/read_write.c:619 dump_emit_page fs/coredump.c:1298 [inline] dump_user_range+0x8a0/0xc90 fs/coredump.c:1372 elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111 coredump_write+0x116c/0x1900 fs/coredump.c:1049 vfs_coredump+0x1db5/0x2a60 fs/coredump.c:1170 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f308cfc1465 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8 RSP: 002b:00007f308deeef80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f308d1d5fa0 RCX: 00007f308cfc1465 RDX: 00007f308deeefc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f308d011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f308d1d6038 R14: 00007f308d1d5fa0 R15: 00007ffeb71f0b38