INFO: task syz.2.113:6747 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.113 state:D stack:24576 pid:6747 tgid:6735 ppid:5797 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 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:1073 [inline] __start_dirop fs/namei.c:2923 [inline] start_dirop fs/namei.c:2934 [inline] filename_unlinkat+0x2ad/0x610 fs/namei.c:5521 __do_sys_unlink fs/namei.c:5575 [inline] __se_sys_unlink+0x2e/0x140 fs/namei.c:5572 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8db645c629 RSP: 002b:00007f8db4695028 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f8db66d6090 RCX: 00007f8db645c629 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000280 RBP: 00007f8db64f2b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8db66d6128 R14: 00007f8db66d6090 R15: 00007ffed39fc698 INFO: task syz.2.113:6765 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.113 state:D stack:29024 pid:6765 tgid:6735 ppid:5797 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 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:1073 [inline] __start_dirop fs/namei.c:2923 [inline] start_dirop fs/namei.c:2934 [inline] filename_create+0x200/0x370 fs/namei.c:4922 filename_mkdirat+0xd2/0x520 fs/namei.c:5259 __do_sys_mkdirat fs/namei.c:5287 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5284 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8db645b507 RSP: 002b:00007f8db4673e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f8db4673ee0 RCX: 00007f8db645b507 RDX: 00000000000001ff RSI: 0000200000000100 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000200000001a00 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000100 R13: 00007f8db4673ea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: 3 locks held by kworker/u8:2/36: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90000ab7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000ab7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 1 lock held by khungtaskd/39: #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:7/983: #0: ffff88801aabc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801aabc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90004dc7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90004dc7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff88801a3e80d0 (&type->s_umount_key#75){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff888060cb6368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 3 locks held by kworker/u8:9/1109: #0: ffff8880325b5938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff8880325b5938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc900050e7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900050e7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 4 locks held by kworker/u8:15/3577: #0: ffff88801aed9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801aed9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc9000f0e7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000f0e7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f14afc0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffff88802a0157b8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249 1 lock held by dhcpcd/5459: #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_deladdr+0x1c1/0x790 net/ipv4/devinet.c:670 2 locks held by getty/5554: #0: ffff8880373e60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:4/5803: #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90004d6fc40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90004d6fc40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 4 locks held by syz.2.113/6739: 2 locks held by syz.2.113/6747: #0: ffff88801a3e8480 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888060cb6738 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888060cb6738 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff888060cb6738 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff888060cb6738 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: filename_unlinkat+0x2ad/0x610 fs/namei.c:5521 2 locks held by syz.2.113/6765: #0: ffff88801a3e8480 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888060cb6738 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888060cb6738 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff888060cb6738 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff888060cb6738 (&type->i_mutex_dir_key#11/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922 1 lock held by syz-executor/7997: #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz.9.237/8038: #0: ffff88801a3e80d0 (&type->s_umount_key#75){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88801a3e80d0 (&type->s_umount_key#75){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 #1: ffff888025dca8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline] #1: ffff888025dca8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2921 1 lock held by syz-executor/8105: #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by syz-executor/8138: #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 3 locks held by syz-executor/8180: #0: ffffffff8f1c7c60 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f1c7a58 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f1c7a58 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f1c7a58 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 #2: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: wg_set_device_doit+0x170/0x2070 drivers/net/wireguard/netlink.c:484 7 locks held by syz-executor/8184: #0: ffff8880332d8480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff8880332d8480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88803ced7c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880288484b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880288484b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e9c7378 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff8880635850d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff8880635850d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline] #4: ffff8880635850d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1304 #5: ffff888037138300 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1778 #6: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1177 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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: 6739 Comm: syz.2.113 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x80 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d f4 8c bb 0b 48 89 de 5b e9 23 8b 5a 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 18 7d 89 10 65 8b 35 39 7d 89 RSP: 0018:ffffc900044cf680 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000080000 RDX: ffffc9000de39000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffff88803b1d6000 R08: 0000000000000000 R09: 0000000000000000 R10: 0030000000000000 R11: 000007ff00000020 R12: dffffc0000000000 R13: 1ffff1100763ac00 R14: 0000000000000000 R15: 1ffff1100763ac02 FS: 00007f8db46b66c0(0000) GS:ffff888126443000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560c729de660 CR3: 0000000024f74000 CR4: 00000000003526f0 Call Trace: dtSplitRoot+0x7a6/0x16c0 fs/jfs/jfs_dtree.c:1981 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xf19/0x5f10 fs/jfs/jfs_dtree.c:871 jfs_mkdir+0x783/0xb00 fs/jfs/namei.c:271 vfs_mkdir+0x40b/0x630 fs/namei.c:5233 filename_mkdirat+0x289/0x520 fs/namei.c:5266 __do_sys_mkdirat fs/namei.c:5287 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5284 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8db645b507 Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 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:00007f8db46b5e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f8db46b5ee0 RCX: 00007f8db645b507 RDX: 00000000000001ff RSI: 0000200000000280 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000280 R13: 00007f8db46b5ea0 R14: 0000000000000000 R15: 0000000000000000