INFO: task syz.4.246:8759 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.246 state:D stack:25624 pid:8759 tgid:8757 ppid:8084 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14de/0x5210 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 __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:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x126/0x290 fs/super.c:926 ksys_sync+0xa0/0x170 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7fa42323bf79 RSP: 002b:00007fa421496028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fa4234b5fa0 RCX: 00007fa42323bf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fa4234b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa4234b6038 R14: 00007fa4234b5fa0 R15: 00007fff24ff9dd8 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 4 locks held by kworker/u8:1/13: #0: ffff88801b289138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801b289138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef3f800 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248 1 lock held by khungtaskd/38: #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:4/68: #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc9000153fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000153fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 2 locks held by kworker/u8:7/1170: #0: ffff88801effc938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801effc938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90004ad7c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90004ad7c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 3 locks held by kworker/u8:11/1503: #0: ffff88805d030938 ((wq_completion)loop6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88805d030938 ((wq_completion)loop6){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90005277c40 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90005277c40 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffff8880250d7160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline] #2: ffff8880250d7160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0x125/0x11b0 drivers/block/loop.c:1954 3 locks held by kworker/u8:14/3917: #0: ffff888031a5d138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888031a5d138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc9000e76fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000e76fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194 7 locks held by kworker/u8:15/3939: 2 locks held by dhcpcd/5462: #0: ffff888067d98928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267 #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 2 locks held by getty/5559: #0: ffff88803703d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:3/5813: #0: ffff88813fe3bd38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe3bd38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90004fa7c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90004fa7c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by syz-executor/7055: 1 lock held by syz.4.246/8759: #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.1.259/8816: #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.9.292/9068: #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by udevd/10006: 3 locks held by syz-executor/10045: #0: ffffffff8efbca20 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8efbc818 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8efbc818 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8efbc818 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1209 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: wg_set_device_doit+0x170/0x2070 drivers/net/wireguard/netlink.c:484 1 lock held by syz.8.411/10116: #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.8.411/10118: #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880530480d0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 7 locks held by syz-executor/10145: #0: ffff888032426480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff888032426480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff888061380478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880282620f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880282620f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e7bc838 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88805f6960d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88805f6960d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline] #4: ffff88805f6960d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1304 #5: ffff888033b28300 (&devlink->lock_key#23){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1778 #6: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2156 1 lock held by syz-executor/10270: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by syz.3.459/10447: 1 lock held by syz.6.460/10467: ============================================= 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 01/24/2026 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+0xf90/0xfe0 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: 3939 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: ocfs2_wq ocfs2_complete_recovery RIP: 0010:mark_lock_accessed kernel/locking/lockdep.c:1530 [inline] RIP: 0010:__bfs+0xf5/0x290 kernel/locking/lockdep.c:1768 Code: 0d 70 1f 92 13 4d 85 ed 0f 84 61 01 00 00 49 8b 45 10 48 85 c0 0f 84 3c 01 00 00 8b 0d 5c 1f 92 13 39 48 5c 0f 84 6f ff ff ff <89> 48 5c 49 8b 45 30 48 85 c0 74 23 41 0f b6 4d 2a 89 ca 80 e2 fa RSP: 0018:ffffc9000e84e7e0 EFLAGS: 00000093 RAX: ffffffff92d1d490 RBX: 0000000000000020 RCX: 0000000000096717 RDX: 0000000000000008 RSI: ffff888033f56658 RDI: ffffffff95b54e10 RBP: ffffffff819f7a40 R08: ffffc9000e84e880 R09: 0000000000000020 R10: ffffc9000e84eb90 R11: ffffffff819f7a40 R12: ffffffff92d295a8 R13: ffffffff95b55c80 R14: 0000000000000000 R15: ffffffff92d295a8 FS: 0000000000000000(0000) GS:ffff888126695000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff602799000 CR3: 00000000337e2000 CR4: 00000000003526f0 Call Trace: __bfs_forwards kernel/locking/lockdep.c:1848 [inline] check_path+0x21/0x40 kernel/locking/lockdep.c:2131 check_noncircular+0xda/0x150 kernel/locking/lockdep.c:2160 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 _raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 raw_spin_rq_lock kernel/sched/sched.h:1615 [inline] ___task_rq_lock+0xc1/0x470 kernel/sched/core.c:725 rt_mutex_setprio+0xc9/0x8e0 kernel/sched/core.c:7322 rt_mutex_adjust_prio kernel/locking/rtmutex.c:539 [inline] mark_wakeup_next_waiter kernel/locking/rtmutex.c:1331 [inline] rt_mutex_slowunlock+0x4b6/0x8b0 kernel/locking/rtmutex.c:1466 spin_unlock_irq include/linux/spinlock_rt.h:122 [inline] loop_queue_work drivers/block/loop.c:864 [inline] loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1890 __blk_mq_issue_directly block/blk-mq.c:2728 [inline] blk_mq_request_issue_directly+0x3be/0x6d0 block/blk-mq.c:2815 blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2836 blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2911 blk_mq_flush_plug_list+0x456/0x570 block/blk-mq.c:2994 __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230 blk_finish_plug block/blk-core.c:1257 [inline] __submit_bio+0x28d/0x580 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x2f4/0xa20 block/blk-core.c:753 ocfs2_read_blocks+0x887/0x14a0 fs/ocfs2/buffer_head_io.c:330 ocfs2_read_inode_block_full fs/ocfs2/inode.c:1715 [inline] ocfs2_read_inode_block+0xec/0x1d0 fs/ocfs2/inode.c:1729 ocfs2_dir_foreach_blk_id fs/ocfs2/dir.c:1791 [inline] ocfs2_dir_foreach_blk+0xc7b/0x1520 fs/ocfs2/dir.c:1954 ocfs2_dir_foreach+0x42/0x70 fs/ocfs2/dir.c:1965 ocfs2_queue_orphans fs/ocfs2/journal.c:2215 [inline] ocfs2_recover_orphans fs/ocfs2/journal.c:2299 [inline] ocfs2_complete_recovery+0xd75/0x2190 fs/ocfs2/journal.c:1366 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 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