INFO: task syz.6.482:11558 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.482 state:D stack:24760 pid:11558 tgid:11557 ppid:10640 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1fc5/0x2600 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:1042 [inline] open_last_lookups fs/namei.c:4548 [inline] path_openat+0xb56/0x3e70 fs/namei.c:4793 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_open fs/open.c:1444 [inline] __se_sys_open fs/open.c:1440 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1440 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff724b7acb9 RSP: 002b:00007ff722dd6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ff724df5fa0 RCX: 00007ff724b7acb9 RDX: 00000000000000a5 RSI: 0000000000004002 RDI: 0000200000000100 RBP: 00007ff724be8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff724df6038 R14: 00007ff724df5fa0 R15: 00007ffcea882328 INFO: task syz.6.482:11603 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.482 state:D stack:25656 pid:11603 tgid:11557 ppid:10640 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 io_schedule+0x80/0xe0 kernel/sched/core.c:7791 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1159 [inline] release_metapage+0x103/0xab0 fs/jfs/jfs_metapage.c:870 discard_metapage fs/jfs/jfs_metapage.h:88 [inline] __get_metapage+0x9a3/0xde0 fs/jfs/jfs_metapage.c:753 dtSearch+0x591/0x21b0 fs/jfs/jfs_dtree.c:624 jfs_lookup+0x1b0/0x420 fs/jfs/namei.c:1461 lookup_one_qstr_excl+0x131/0x360 fs/namei.c:1755 __start_dirop fs/namei.c:2875 [inline] start_dirop fs/namei.c:2884 [inline] do_rmdir+0x1d9/0x470 fs/namei.c:5293 __do_sys_rmdir fs/namei.c:5324 [inline] __se_sys_rmdir fs/namei.c:5322 [inline] __x64_sys_rmdir+0x47/0x50 fs/namei.c:5322 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff724b7acb9 RSP: 002b:00007ff722db5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007ff724df6090 RCX: 00007ff724b7acb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000040 RBP: 00007ff724be8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff724df6128 R14: 00007ff724df6090 R15: 00007ffcea882328 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88801a2d4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801a2d4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8ec9b480 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffff88805e4b57b8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249 1 lock held by khungtaskd/38: #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:9/1024: #0: ffff88814047c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88814047c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000478fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000478fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 2 locks held by kworker/u8:10/1179: 2 locks held by kworker/u8:15/3481: #0: ffff88813fe69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000d4c7bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000d4c7bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 2 locks held by getty/5559: #0: ffff888030d240a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by udevd/11384: 1 lock held by syz.6.482/11558: #0: ffff88803e2e53b8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline] #0: ffff88803e2e53b8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: open_last_lookups fs/namei.c:4548 [inline] #0: ffff88803e2e53b8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: path_openat+0xb56/0x3e70 fs/namei.c:4793 2 locks held by syz.6.482/11603: #0: ffff8880605fa480 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88803e2e53b8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88803e2e53b8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline] #1: ffff88803e2e53b8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline] #1: ffff88803e2e53b8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: do_rmdir+0x1c6/0x470 fs/namei.c:5293 2 locks held by syz.5.538/12214: #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 #1: ffff88803d51a150 (&(log)->loglock){+.+.}-{4:4}, at: jfs_syncpt+0x25/0x90 fs/jfs/jfs_logmgr.c:1039 2 locks held by syz.5.538/12217: #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 #1: ffff88803d51a150 (&(log)->loglock){+.+.}-{4:4}, at: jfs_syncpt+0x25/0x90 fs/jfs/jfs_logmgr.c:1039 2 locks held by syz.5.538/12218: #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 #1: ffff88803d51a150 (&(log)->loglock){+.+.}-{4:4}, at: jfs_syncpt+0x25/0x90 fs/jfs/jfs_logmgr.c:1039 2 locks held by syz.5.538/12220: #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 #1: ffff88803d51a150 (&(log)->loglock){+.+.}-{4:4}, at: jfs_syncpt+0x25/0x90 fs/jfs/jfs_logmgr.c:1039 2 locks held by syz.5.538/12223: #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880605fa0d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 #1: ffff88803d51a150 (&(log)->loglock){+.+.}-{4:4}, at: jfs_syncpt+0x25/0x90 fs/jfs/jfs_logmgr.c:1039 1 lock held by udevd/12814: #0: ffff888010c2aa08 (&ep->lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline] #0: ffff888010c2aa08 (&ep->lock){+.+.}-{3:3}, at: ep_poll fs/eventpoll.c:2040 [inline] #0: ffff888010c2aa08 (&ep->lock){+.+.}-{3:3}, at: do_epoll_wait+0x851/0xbd0 fs/eventpoll.c:2461 6 locks held by syz-executor/13254: 2 locks held by syz.3.673/13725: 2 locks held by syz.8.678/13702: 7 locks held by udevadm/13723: 3 locks held by syz.1.679/13729: 4 locks held by modprobe/13731: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1179 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: bat_events batadv_dat_purge RIP: 0010:rtlock_lock kernel/locking/spinlock_rt.c:40 [inline] RIP: 0010:__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] RIP: 0010:rt_spin_lock+0x10f/0x400 kernel/locking/spinlock_rt.c:57 Code: 3d a5 45 2c 04 00 74 2d 48 8b 44 24 10 4c 8d a0 10 0b 00 00 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 d1 33 35 f7 <49> 83 3c 24 00 0f 85 01 02 00 00 48 89 5c 24 18 66 42 c7 44 2b 04 RSP: 0018:ffffc90004c3f940 EFLAGS: 00000246 RAX: 1ffff11004dc98f2 RBX: 1ffff92000987f2c RCX: 0000000000000046 RDX: 0000000000000100 RSI: ffffffff8d281852 RDI: ffffffff8b5f6260 RBP: ffffc90004c3f9f8 R08: ffffffff8ab77061 R09: ffff888050a676d8 R10: dffffc0000000000 R11: fffffbfff1e36e0f R12: ffff888026e4c790 R13: dffffc0000000000 R14: ffff888050a67680 R15: ffffc90004c3f980 FS: 0000000000000000(0000) GS:ffff8881269d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f29b3fb7000 CR3: 000000000d7a8000 CR4: 00000000003526f0 Call Trace: spin_lock_bh include/linux/spinlock_rt.h:88 [inline] __batadv_dat_purge+0x131/0x400 net/batman-adv/distributed-arp-table.c:173 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246