INFO: task syz-executor:16343 blocked for more than 143 seconds. Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:18984 pid:16343 tgid:16343 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833 sync_filesystem+0x17a/0x230 fs/sync.c:64 generic_shutdown_super+0x6f/0x2c0 fs/super.c:622 kill_block_super+0x44/0x90 fs/super.c:1755 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2318 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5bdc78fc57 RSP: 002b:00007ffc4c7aa088 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f5bdc810925 RCX: 00007f5bdc78fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc4c7aa140 RBP: 00007ffc4c7aa140 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc4c7ab1d0 R13: 00007f5bdc810925 R14: 00000000000db444 R15: 00007ffc4c7ab210 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by khungtaskd/31: #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 5 locks held by kworker/u8:3/49: #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000ba7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000ba7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f4f1410 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662 #3: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:174 [inline] #3: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:249 #4: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #4: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 2 locks held by kworker/u8:6/1321: 4 locks held by kworker/u8:8/3463: 3 locks held by kworker/u8:9/3521: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000bc77bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000bc77bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 3 locks held by kworker/u8:10/3542: #0: ffff888030375948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888030375948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000bc27bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4198 1 lock held by dhcpcd/5491: #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1121 2 locks held by getty/5587: #0: ffff888030d9e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:3/5837: #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc900041bfbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] ffffc900041bfbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by syz-executor/16343: #0: ffff8880282a40e0 (&type->s_umount_key#62){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] ffff8880282a40e0 (&type->s_umount_key#62){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] ffff8880282a40e0 (&type->s_umount_key#62){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff888142bc67d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888142bc67d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 1 lock held by udevd/16432: 2 locks held by syz-executor/16997: #0: ffffffff8e87e528 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8e87e528 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1758 #1: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3782 1 lock held by syz-executor/18165: #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 7 locks held by syz-executor/18453: #0: ffff88803523a428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline] #0: ffff88803523a428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682 #1: ffff888055ca1488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff888143bedb48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8ed98ca8 (nsim_bus_dev_list_lock){+.+.}-{4:4} , at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216 #4: ffff88805e8b40e8 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: __device_driver_lock drivers/base/dd.c:1094 [inline] , at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292 #5: ffff88805e8b5250 (&devlink->lock_key#29){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2143 1 lock held by syz-executor/18526: #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 16432 Comm: udevd Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:number+0x44b/0xf60 lib/vsprintf.c:521 Code: 0f 4f e8 44 29 eb 44 89 fe 83 e6 12 31 ff e8 4c e7 64 f6 44 89 f8 83 e0 12 74 64 48 89 5c 24 18 e8 fa e2 64 f6 80 7c 24 38 00 <74> 1a e8 ee e2 64 f6 80 7c 24 07 00 0f 85 07 01 00 00 e8 de e2 64 RSP: 0018:ffffc90003c9eaa0 EFLAGS: 00000202 RAX: 00000000ffffffff RBX: 0000000000000000 RCX: ffff8880257d5a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: ffffc90003c9ebc0 R08: ffffc90003c9eb37 R09: 0000000000000000 R10: ffffc90003c9eb20 R11: fffff52000793d67 R12: 0000000000000429 R13: 0000000000000004 R14: ffffc90003c9eea2 R15: 00000000ffff0a00 FS: 00007f4b04e67880(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4b04e20000 CR3: 000000007d276000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x91b/0xf00 lib/vsprintf.c:2838 sprintf+0xd9/0x120 lib/vsprintf.c:3037 print_time kernel/printk/printk.c:1381 [inline] info_print_prefix+0x155/0x310 kernel/printk/printk.c:1407 record_print_text+0x154/0x430 kernel/printk/printk.c:1456 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:3024 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x4ca/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 audit_log_start+0x7b4/0x870 kernel/audit.c:1904 common_lsm_audit+0xba/0x2e0 security/lsm_audit.c:442 smack_log+0x394/0x3f0 security/smack/smack_access.c:391 smk_tskacc+0x2fc/0x370 security/smack/smack_access.c:255 smack_inode_permission+0x28f/0x320 security/smack/smack_lsm.c:1217 security_inode_permission+0xf8/0x310 security/security.c:2324 may_lookup fs/namei.c:1845 [inline] link_path_walk+0x232/0xea0 fs/namei.c:2454 path_parentat fs/namei.c:2710 [inline] __filename_parentat+0x246/0x670 fs/namei.c:2734 filename_parentat fs/namei.c:2752 [inline] do_renameat2+0x214/0xc50 fs/namei.c:5204 __do_sys_rename fs/namei.c:5333 [inline] __se_sys_rename fs/namei.c:5331 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5331 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4b0467acc7 Code: e8 5e a7 09 00 f7 d8 19 c0 5b c3 0f 1f 84 00 00 00 00 00 b8 ff ff ff ff 5b c3 66 0f 1f 84 00 00 00 00 00 b8 52 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 01 61 17 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffd1c820708 EFLAGS: 00000206 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 0000559c0a037770 RCX: 00007f4b0467acc7 RDX: 0000559c0a01a010 RSI: 00007ffd1c820720 RDI: 00007ffd1c820b20 RBP: 0000559c0a02ddf0 R08: 00000000000001e0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffd1c820720 R13: 00007ffd1c820b20 R14: 0000000000000000 R15: 0000559c0a038d30