INFO: task syz.3.124:6718 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.124 state:D stack:28264 pid:6718 tgid:6675 ppid:5840 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 f2fs_down_write fs/f2fs/f2fs.h:2234 [inline] f2fs_issue_checkpoint+0x39c/0x570 fs/f2fs/checkpoint.c:1846 f2fs_do_sync_file+0x86c/0x1860 fs/f2fs/file.c:346 vfs_fsync_range fs/sync.c:187 [inline] vfs_fsync fs/sync.c:201 [inline] do_fsync fs/sync.c:212 [inline] __do_sys_fdatasync fs/sync.c:222 [inline] __se_sys_fdatasync fs/sync.c:220 [inline] __x64_sys_fdatasync+0xbc/0x110 fs/sync.c:220 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: 0033:0x7f711554ebe9 RSP: 002b:00007f711376c038 EFLAGS: 00000246 ORIG_RAX: 000000000000004b RAX: ffffffffffffffda RBX: 00007f7115786180 RCX: 00007f711554ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009 RBP: 00007f71155d1e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7115786218 R14: 00007f7115786180 R15: 00007fff65b9bcc8 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:3/57: #0: ffff8881404a3138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff8881404a3138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000123fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000123fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff8880615ea0d0 (&type->s_umount_key#88){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff888061129990 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2234 [inline] #3: ffff888061129990 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_issue_checkpoint+0x39c/0x570 fs/f2fs/checkpoint.c:1846 2 locks held by kworker/u8:4/67: 7 locks held by kworker/u8:8/1401: 2 locks held by kworker/u8:9/1652: #0: ffff888147e94938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888147e94938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90005897bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005897bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 1 lock held by dhcpcd/5502: #0: ffffffff8ecd22b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd22b8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 2 locks held by getty/5601: #0: ffff88814e3470a0 (&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+0x444/0x1410 drivers/tty/n_tty.c:2222 2 locks held by udevd/5894: 1 lock held by udevd/5970: 3 locks held by syz.3.124/6708: 1 lock held by syz.3.124/6718: #0: ffff888061129990 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2234 [inline] #0: ffff888061129990 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_issue_checkpoint+0x39c/0x570 fs/f2fs/checkpoint.c:1846 2 locks held by syz.2.247/7375: #0: ffff8880615ea0d0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880615ea0d0 (&type->s_umount_key#88){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff888142f44870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888142f44870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz-executor/7743: #0: ffffffff8e43ac20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e43ac20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e43ac20 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ecd22b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ecd22b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ecd22b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 5 locks held by kworker/u8:14/7856: 3 locks held by kworker/u8:15/7863: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000cb5fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000cb5fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd22b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 5 locks held by syz.7.313/7924: 1 lock held by syz.0.315/7935: ============================================= 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 07/12/2025 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:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_wait_context kernel/locking/lockdep.c:-1 [inline] RIP: 0010:__lock_acquire+0x38b/0xd20 kernel/locking/lockdep.c:5187 Code: 00 75 19 90 48 c7 c7 ba 7b 21 8d 48 c7 c6 d1 69 11 8d e8 98 37 e7 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 0f b6 98 c4 00 00 00 <41> 8b 46 20 25 ff 1f 00 00 48 0f a3 05 14 9c 61 11 73 17 48 69 c0 RSP: 0018:ffffc90000157970 EFLAGS: 00000002 RAX: ffffffff929f7a30 RBX: 0000000000000003 RCX: 0000000000000128 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801c295940 RBP: 0000000000000128 R08: 0000000000000000 R09: ffffffff8184cc24 R10: 0000000000000100 R11: ffffffff818505f0 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88801c296488 R15: ffff88801c296460 FS: 0000000000000000(0000) GS:ffff8881268c2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd4cf5a4000 CR3: 0000000032552000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 rt_spin_lock+0x88/0x2c0 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:44 [inline] __local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168 ksoftirqd_run_begin kernel/softirq.c:273 [inline] run_ktimerd+0x6b/0x190 kernel/softirq.c:1037 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245