INFO: task syz.6.1023:15747 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1023 state:D stack:28552 pid:15747 tgid:15728 ppid:14799 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7558 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1659 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1736 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1776 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1816 __rt_mutex_lock kernel/locking/rtmutex.c:1831 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:245 inode_lock include/linux/fs.h:1029 [inline] open_last_lookups fs/namei.c:4608 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4855 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd00019c819 RSP: 002b:00007fcff5fac028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fd000416180 RCX: 00007fd00019c819 RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007fd000232c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd000416218 R14: 00007fd000416180 R15: 00007ffec687c008 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/56: #0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371 #1: ffffc9000122fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc9000122fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371 4 locks held by kworker/u8:4/67: #0: ffff88801b285138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff88801b285138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371 #1: ffffc9000152fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc9000152fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371 #2: ffff888030bd00d0 (&type->s_umount_key#96){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff888062e43230 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 2 locks held by kworker/u8:13/1513: #0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371 #1: ffffc90006e5fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc90006e5fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371 3 locks held by kworker/u8:16/3555: #0: ffff88801b6a9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff88801b6a9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371 #1: ffffc9000eff7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc9000eff7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371 #2: ffffffff8f34ac60 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 2 locks held by getty/5555: #0: ffff8880385570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 4 locks held by syz.6.1023/15744: 2 locks held by syz.6.1023/15747: #0: ffff888030bd0480 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888062e43600 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #1: ffff888062e43600 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: open_last_lookups fs/namei.c:4608 [inline] #1: ffff888062e43600 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4855 1 lock held by syz-executor/15837: #0: ffff888063c260d0 (&type->s_umount_key#96){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888063c260d0 (&type->s_umount_key#96){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888063c260d0 (&type->s_umount_key#96){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 2 locks held by syz.9.1053/15951: #0: ffff888030bd00d0 (&type->s_umount_key#96){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888030bd00d0 (&type->s_umount_key#96){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 #1: ffff8880268708c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline] #1: ffff8880268708c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940 9 locks held by udevd/15985: 8 locks held by syz-executor/16915: 3 locks held by syz.8.1181/17110: 5 locks held by dhcpcd-run-hook/17118: #0: ffff88807b4d2e48 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:288 #2: ffff888041f8ec58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff888041f8ec58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:402 #3: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8dfc8400 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #4: ffff8880b8833ed0 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #4: ffff8880b8833ed0 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x283/0xa90 mm/swap.c:-1 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfaa/0x1000 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17110 Comm: syz.8.1181 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:110 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x2b7/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: ff df 0f 84 17 04 00 00 4a 8d 14 ad b4 cf 9b 8f 45 29 e8 4a 8d 1c 82 48 83 c3 fc 49 89 d5 48 39 da 0f 86 1c 02 00 00 49 29 d5 <49> c1 fd 02 4a 8d 04 6d 00 00 00 00 4c 01 e8 48 8d 14 46 48 bd 00 RSP: 0018:ffffc9000692ef58 EFLAGS: 00000246 RAX: ffffffff8faa47f4 RBX: ffffffff8faa47f8 RCX: ffffffff8faa47fc RDX: ffffffff8faa47f8 RSI: ffffffff9024d8d2 RDI: ffffffff8ba684a0 RBP: ffffffff8faa47fc R08: 0000000000000009 R09: ffffffff8dfc8400 R10: ffffc9000692f078 R11: ffffffff81af6f50 R12: ffffffff821ff83a R13: 0000000000000000 R14: ffffc9000692f028 R15: ffffffff8faa47f8 FS: 00007f9067f166c0(0000) GS:ffff888126125000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd601b60000 CR3: 000000008e2b4000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4873 __kernfs_new_node+0xea/0x980 fs/kernfs/dir.c:664 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:748 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x673/0x1180 fs/sysfs/group.c:189 internal_create_groups fs/sysfs/group.c:229 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:255 create_dir lib/kobject.c:78 [inline] kobject_add_internal+0x678/0xd10 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x12b/0x1a0 lib/kobject.c:457 f2fs_register_sysfs+0xca/0x4c0 fs/f2fs/sysfs.c:2025 f2fs_fill_super+0x615b/0x76a0 fs/f2fs/super.c:5208 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9069cbda8a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9067f15e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f9067f15ee0 RCX: 00007f9069cbda8a RDX: 0000200000000000 RSI: 0000200000000040 RDI: 00007f9067f15ea0 RBP: 0000200000000000 R08: 00007f9067f15ee0 R09: 0000000000000008 R10: 0000000000000008 R11: 0000000000000246 R12: 0000200000000040 R13: 00007f9067f15ea0 R14: 0000000000005505 R15: 0000200000005980