INFO: task syz.3.1325:16671 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1325 state:D stack:24120 pid:16671 tgid:16668 ppid:12798 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1662 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline] __rt_mutex_slowlock_locked+0x1f28/0x2550 kernel/locking/rtmutex.c:1779 __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:1496 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1570 nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221 nilfs_write_begin+0x71/0x120 fs/nilfs2/inode.c:228 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4325 generic_file_write_iter+0x14b/0x690 mm/filemap.c:4468 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_write+0x156/0x270 fs/read_write.c:740 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: 0033:0x7f48bb04cdd9 RSP: 002b:00007f48b929e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f48bb2c5fa0 RCX: 00007f48bb04cdd9 RDX: 000000000000001b RSI: 0000200000000140 RDI: 0000000000000005 RBP: 00007f48bb0e2d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f48bb2c6038 R14: 00007f48bb2c5fa0 R15: 00007ffffae934e8 INFO: task syz.3.1325:16683 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1325 state:D stack:25592 pid:16683 tgid:16668 ppid:12798 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 __wait_on_freeing_inode+0x214/0x3b0 fs/inode.c:2554 find_inode+0x311/0x550 fs/inode.c:1061 inode_insert5+0x127/0x5e0 fs/inode.c:1310 insert_inode_locked4+0x74/0xc0 fs/inode.c:1889 nilfs_insert_inode_locked fs/nilfs2/inode.c:297 [inline] nilfs_new_inode+0x4db/0x800 fs/nilfs2/inode.c:351 nilfs_mkdir+0x114/0x340 fs/nilfs2/namei.c:234 vfs_mkdir+0x40b/0x630 fs/namei.c:5261 filename_mkdirat+0x289/0x520 fs/namei.c:5294 __do_sys_mkdirat fs/namei.c:5315 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5312 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: 0033:0x7f48bb04bc47 RSP: 002b:00007f48b927ce58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f48b927cee0 RCX: 00007f48bb04bc47 RDX: 00000000000001ff RSI: 0000200000000280 RDI: 00000000ffffff9c RBP: 0000200000000000 R08: 0000200000000d40 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000200000000280 R13: 00007f48b927cea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 6 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/38: #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:7/212: #0: ffff8880334d9138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff8880334d9138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90003a9fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90003a9fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206 3 locks held by kworker/u8:8/1028: #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90005ef7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90005ef7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by kworker/u8:9/1043: #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90005f67c40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90005f67c40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 8 locks held by kworker/u8:13/2123: 3 locks held by kworker/0:3/4978: #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90003d4fc40 ((work_completion)(&sci->sc_iput_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90003d4fc40 ((work_completion)(&sci->sc_iput_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff888056cac770 (sb_internal#3){.+.+}-{0:0}, at: nilfs_evict_inode+0x167/0x4b0 fs/nilfs2/inode.c:868 2 locks held by getty/5346: #0: ffff88823be548a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cb32e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/12756: 2 locks held by udevd/14123: 5 locks held by syz.3.1325/16671: #0: ffff88802b6f7f28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1261 #1: ffff888056cac480 (sb_writers#19){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline] #1: ffff888056cac480 (sb_writers#19){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #2: ffff88805fef82c0 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #2: ffff88805fef82c0 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: generic_file_write_iter+0x11f/0x690 mm/filemap.c:4465 #3: ffff888056cac770 (sb_internal#3){.+.+}-{0:0}, at: nilfs_write_begin+0x71/0x120 fs/nilfs2/inode.c:228 #4: ffff88803db702b0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221 4 locks held by syz.3.1325/16683: #0: ffff888056cac480 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805fefe710 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline] #1: ffff88805fefe710 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline] #1: ffff88805fefe710 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline] #1: ffff88805fefe710 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4950 #2: ffff888056cac770 (sb_internal#3){.+.+}-{0:0}, at: nilfs_mkdir+0xd6/0x340 fs/nilfs2/namei.c:228 #3: ffff88803db702b0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221 1 lock held by segctord/16682: #0: ffff88803db702b0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_lock+0x252/0x4c0 fs/nilfs2/segment.c:357 3 locks held by kworker/0:6/17741: #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc9000df6fc40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc9000df6fc40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x1c/0x450 net/core/dev_addr_lists.c:1312 7 locks held by syz-executor/18040: #0: ffff88803803c480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline] #0: ffff88803803c480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff8880630e6c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880299384b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880299384b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ebcec58 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff888026420160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff888026420160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #4: ffff888026420160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372 #5: ffff88805ab06310 (&devlink->lock_key#36){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799 #6: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2162 2 locks held by syz-executor/18194: #0: ffffffff8f8a6b58 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8f8a6b58 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8f8a6b58 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4108 1 lock held by syz.9.1656/18479: 2 locks held by syz.4.1662/18497: ============================================= 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 04/18/2026 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12061 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4855 [inline] RIP: 0010:__lock_acquire+0x3c4/0x2cf0 kernel/locking/lockdep.c:5187 Code: b3 eb 0d 48 c7 c6 18 56 71 8d 67 48 0f b9 3a 90 31 c0 0f b6 98 c4 00 00 00 41 8b 45 20 25 ff 1f 00 00 48 0f a3 05 6c ae d1 11 <73> 17 48 69 c0 c8 00 00 00 48 8d 88 30 f3 12 93 84 db 75 3f e9 10 RSP: 0018:ffffc9000459edd8 EFLAGS: 00000003 RAX: 0000000000000110 RBX: 0000000000000000 RCX: 0000000000000110 RDX: 0000000000080000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000002 R08: ffffffff819e8623 R09: ffff8880b89246c8 R10: dffffc0000000000 R11: ffffed1004f8db89 R12: 0000000000000110 R13: ffff888027c6e888 R14: ffff888027c6dc40 R15: ffff888027c6e838 FS: 00007f807dbe0880(0000) GS:ffff88812627c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa5112e5000 CR3: 000000006899c000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 do_write_seqcount_begin_nested include/linux/seqlock.h:478 [inline] do_write_seqcount_begin include/linux/seqlock.h:504 [inline] psi_write_begin+0xab/0x160 kernel/sched/psi.c:183 psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 psi_sched_switch kernel/sched/stats.h:225 [inline] __schedule+0x284f/0x54c0 kernel/sched/core.c:7182 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 81 c5 7b 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 5b 00 ca 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 80 89 7f 09 cc 48 8d 3d 38 b8 eb RSP: 0018:ffffc9000459f3b8 EFLAGS: 00000286 RAX: 4fe446ed865f7a00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 000000005f479b93 RSI: ffffffff8d860c1e RDI: ffffffff8ba74c60 RBP: ffffffff8176d226 R08: ffffffff8176d226 R09: ffffffff8dfc8140 R10: ffffc9000459f518 R11: ffffffff81af8dc0 R12: 0000000000000002 R13: ffffffff8dfc8140 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495 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:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4905 alloc_empty_file+0x5b/0x1d0 fs/file_table.c:262 path_openat+0x11b/0x38a0 fs/namei.c:4844 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: 0033:0x7f807dcce407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffcda3e0c40 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f807dbe0880 RCX: 00007f807dcce407 RDX: 0000000000080000 RSI: 00007f807e40bf48 RDI: 000000000000000b RBP: 0000557f2bdc4550 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000080000 R13: 00007f807e40bf48 R14: 0000000000000000 R15: 0000000000000009