INFO: task syz.4.472:9561 blocked for more than 143 seconds. Not[ 562.490766][ T39] Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.472 state:D stack:24584 pid:9561 tgid:9560 ppid:5800 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 io_schedule+0x81/0xe0 kernel/sched/core.c:7871 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1330 folio_lock include/linux/pagemap.h:1141 [inline] release_metapage+0x103/0xab0 fs/jfs/jfs_metapage.c:870 discard_metapage fs/jfs/jfs_metapage.h:88 [inline] __get_metapage+0x9a0/0xde0 fs/jfs/jfs_metapage.c:753 dtSplitPage+0x7f8/0x3b20 fs/jfs/jfs_dtree.c:1471 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0x109b/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_create+0x6c8/0xa80 fs/jfs/namei.c:137 lookup_open fs/namei.c:3796 [inline] open_last_lookups fs/namei.c:3895 [inline] path_openat+0x1500/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f251b8aeec9 RSP: 002b:00007f2519b0e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f251bb05fa0 RCX: 00007f251b8aeec9 RDX: 0000000000105042 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f251b931f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f251bb06038 R14: 00007f251bb05fa0 R15: 00007ffda5b09ad8 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:9/1857: #0: ffff8881432d2138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8881432d2138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90005cbfba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90005cbfba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88805c5700d0 (&type->s_umount_key#103){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88805f5f9568 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 7 locks held by kworker/u8:10/3884: 2 locks held by getty/5560: #0: ffff88823bf700a0 (&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+0x444/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz.4.472/9561: #0: ffff88805c570480 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88805f5f9938 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff88805f5f9938 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88805f5f9938 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 #2: ffff88805f5f9568 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_create+0x1f5/0xa80 fs/jfs/namei.c:100 #3: ffff88805f5fa8e8 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_create+0x210/0xa80 fs/jfs/namei.c:101 3 locks held by kworker/1:6/9732: 2 locks held by syz.5.502/9859: #0: ffff88805c5700d0 (&type->s_umount_key#103){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88805c5700d0 (&type->s_umount_key#103){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88814432e8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88814432e8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2871 2 locks held by kworker/u8:13/10107: #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003e37ba0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003e37ba0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 1 lock held by udevd/10151: 2 locks held by syz-executor/11256: #0: ffffffff8e2108c0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e2108c0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e2108c0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ea78478 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 1 lock held by syz.8.654/11302: 4 locks held by syz.6.659/11283: 4 locks held by syz.2.662/11312: 1 lock held by udevadm/11334: 4 locks held by sed/11337: ============================================= 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 10/02/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 3884 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: netns cleanup_net RIP: 0010:__sanitizer_cov_trace_switch+0x37/0x150 kernel/kcov.c:334 Code: c1 f8 48 c1 c1 3d 48 83 f9 02 7f 1e 48 85 c9 74 3c 48 83 f9 01 0f 85 13 01 00 00 b9 03 00 00 00 48 85 c0 75 36 e9 04 01 00 00 <48> 83 f9 03 0f 84 ec 00 00 00 48 83 f9 07 0f 85 f0 00 00 00 b9 07 RSP: 0000:ffffc9000e836d18 EFLAGS: 00000202 RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000003 RDX: 0000000000000000 RSI: ffffffff8eb87de0 RDI: 0000000000000000 RBP: ffff88802ccaaa80 R08: ffff888031c28000 R09: 0000000000000005 R10: 0000000000000100 R11: 0000000000000004 R12: ffff88802ccaaa80 R13: ffffc9000e836eb8 R14: dffffc0000000000 R15: ffffc9000e836e98 FS: 0000000000000000(0000) GS:ffff888126cc6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1683eb3000 CR3: 0000000035726000 CR4: 00000000003526f0 Call Trace: fib6_walk_continue+0x131/0x910 net/ipv6/ip6_fib.c:2133 fib6_walk+0x16b/0x2f0 net/ipv6/ip6_fib.c:2219 fib6_clean_tree net/ipv6/ip6_fib.c:2299 [inline] __fib6_clean_all+0x25c/0x3b0 net/ipv6/ip6_fib.c:2315 rt6_sync_down_dev net/ipv6/route.c:5003 [inline] rt6_disable_ip+0x117/0x730 net/ipv6/route.c:5008 addrconf_ifdown+0x153/0x18c0 net/ipv6/addrconf.c:3853 addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] netif_close_many+0x29c/0x410 net/core/dev.c:1784 netif_close_many_and_unlock net/core/dev.c:12184 [inline] unregister_netdevice_many_notify+0x801/0x2380 net/core/dev.c:12248 unregister_netdevice_many net/core/dev.c:12347 [inline] unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:12161 unregister_netdevice include/linux/netdevice.h:3389 [inline] nsim_destroy+0x1dd/0x670 drivers/net/netdevsim/netdev.c:1178 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1473 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1485 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1707 nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:983 devlink_reload+0x1b6/0x8d0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1d9/0x3d0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:161 [inline] ops_undo_list+0x187/0x990 net/core/net_namespace.c:234 cleanup_net+0x4de/0x820 net/core/net_namespace.c:695 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245