INFO: task syz.0.509:10065 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.509 state:D stack:28088 pid:10065 tgid:10063 ppid:5805 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] 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 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1072 [inline] lock_rename fs/namei.c:3721 [inline] __start_renaming+0x148/0x410 fs/namei.c:3817 do_renameat2+0x3c9/0x910 fs/namei.c:6031 __do_sys_renameat2 fs/namei.c:6086 [inline] __se_sys_renameat2 fs/namei.c:6083 [inline] __x64_sys_renameat2+0xce/0xe0 fs/namei.c:6083 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: 0033:0x7fe0d172acb9 RSP: 002b:00007fe0cf965028 EFLAGS: 00000246 ORIG_RAX: 000000000000013c RAX: ffffffffffffffda RBX: 00007fe0d19a6090 RCX: 00007fe0d172acb9 RDX: 0000000000000006 RSI: 0000200000000040 RDI: 0000000000000005 RBP: 00007fe0d1798bf7 R08: 0000000000000002 R09: 0000000000000000 R10: 00002000000002c0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe0d19a6128 R14: 00007fe0d19a6090 R15: 00007fffd17ef7d8 INFO: task syz.0.509:10066 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.509 state:D stack:28632 pid:10066 tgid:10063 ppid:5805 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] 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 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1072 [inline] __start_dirop fs/namei.c:2873 [inline] start_dirop fs/namei.c:2884 [inline] filename_create+0x200/0x370 fs/namei.c:4888 do_mkdirat+0xd2/0x4c0 fs/namei.c:5165 __do_sys_mkdirat fs/namei.c:5195 [inline] __se_sys_mkdirat fs/namei.c:5193 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5193 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: 0033:0x7fe0d1729b97 RSP: 002b:00007fe0cf943e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fe0cf943ee0 RCX: 00007fe0d1729b97 RDX: 00000000000001ff RSI: 0000200000000280 RDI: 00000000ffffff9c RBP: 0000200000000040 R08: 00002000000007c0 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000200000000280 R13: 00007fe0cf943ea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 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 4 locks held by kworker/u8:12/1737: #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: ffffc90005bdfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90005bdfbc0 (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: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe5/0xa10 net/core/dev.c:13037 4 locks held by kworker/u8:16/3566: #0: ffff8881416e9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff8881416e9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000d30fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000d30fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff8880628a80d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff8880661101e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 3 locks held by kworker/u8:18/3847: #0: ffff88813fe69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000d9efbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000d9efbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by dhcpcd/5467: #0: ffff888028f96928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 2 locks held by getty/5562: #0: ffff88814e4f50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by syz.0.509/10064: 2 locks held by syz.0.509/10065: #0: ffff8880628a8480 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff8880661105b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff8880661105b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3721 [inline] #1: ffff8880661105b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3817 2 locks held by syz.0.509/10066: #0: ffff8880628a8480 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff8880661105b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff8880661105b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline] #1: ffff8880661105b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline] #1: ffff8880661105b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4888 3 locks held by kworker/1:2/10108: #0: ffff88813fe56138 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe56138 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc900053ffbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900053ffbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xa5/0xf40 net/wireless/reg.c:2453 1 lock held by syz-executor/10697: #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5027 3 locks held by kworker/u8:23/10789: #0: ffff88802fde3138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88802fde3138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000474fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000474fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194 7 locks held by syz-executor/10791: #0: ffff888031d5a480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888031d5a480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682 #1: ffff88805bd6f478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888142779f08 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888142779f08 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e52ccb8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88805f13b0d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88805f13b0d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #4: ffff88805f13b0d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1302 #5: ffff888032273300 (&devlink->lock_key#28){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1777 #6: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_notifier_net+0x87/0x2e0 net/core/dev.c:2125 4 locks held by syz-executor/10803: #0: ffff888031d5a480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888031d5a480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682 #1: ffff8880382d9478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888142779f08 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888142779f08 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e52ccb8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 2 locks held by syz-executor/10914: #0: ffffffff8ec9b480 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cb/0x570 net/core/net_namespace.c:577 #1: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146 1 lock held by syz-executor/10920: #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8eca88b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 ============================================= 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 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 10064 Comm: syz.0.509 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x80 kernel/kcov.c:217 Code: 33 10 81 e6 00 00 ff 00 ba 00 01 00 00 23 91 7c 0b 00 00 89 d7 09 f7 74 11 85 f6 75 39 85 d2 74 35 83 b9 3c 16 00 00 00 74 2c <8b> 91 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 RSP: 0018:ffffc900049df6a0 EFLAGS: 00000246 RAX: ffffffff834559a6 RBX: 0000000000000004 RCX: ffff88802b5b3c80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888011203000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: 1ffff11002240600 R14: 0000000000000000 R15: 1ffff11002240602 FS: 00007fe0cf9866c0(0000) GS:ffff8881268d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb3d1430345 CR3: 0000000032d4c000 CR4: 00000000003526f0 Call Trace: dtSplitRoot+0x7a6/0x16c0 fs/jfs/jfs_dtree.c:1981 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xedd/0x5de0 fs/jfs/jfs_dtree.c:871 jfs_mkdir+0x783/0xb00 fs/jfs/namei.c:270 vfs_mkdir+0x52c/0x5d0 fs/namei.c:5139 do_mkdirat+0x281/0x4c0 fs/namei.c:5173 __do_sys_mkdirat fs/namei.c:5195 [inline] __se_sys_mkdirat fs/namei.c:5193 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5193 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: 0033:0x7fe0d172acb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fe0cf986028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fe0d19a5fa0 RCX: 00007fe0d172acb9 RDX: 0000000000000000 RSI: 0000200000000340 RDI: 0000000000000005 RBP: 00007fe0d1798bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe0d19a6038 R14: 00007fe0d19a5fa0 R15: 00007fffd17ef7d8