INFO: task kworker/u8:0:11 blocked for more than 143 seconds. Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:0 state:D stack:21232 pid:11 tgid:11 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x17fa/0x4bd0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102 jfs_write_inode+0x143/0x220 fs/jfs/inode.c:132 write_inode fs/fs-writeback.c:1503 [inline] __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1723 writeback_sb_inodes+0x80c/0x1370 fs/fs-writeback.c:1954 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2025 wb_writeback+0x42f/0xbd0 fs/fs-writeback.c:2136 wb_check_old_data_flush fs/fs-writeback.c:2240 [inline] wb_do_writeback fs/fs-writeback.c:2293 [inline] wb_workfn+0xba1/0x1090 fs/fs-writeback.c:2321 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 4 locks held by kworker/u8:0/11: #0: ffff88801e6bd948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801e6bd948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff8880573460e0 (&type->s_umount_key#68){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88807cf9a6a8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by kworker/u8:2/35: 2 locks held by kworker/u8:4/67: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900020afd00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900020afd00 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 2 locks held by kworker/u8:6/1141: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90003cc7d00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003cc7d00 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 2 locks held by dhcpcd/5497: #0: ffff8880361516c8 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2405 #1: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6534 2 locks held by getty/5584: #0: ffff88814d4b70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 4 locks held by syz.0.196/7481: 5 locks held by kworker/u8:9/8037: #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900195cfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900195cfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcb4890 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:11938 #4: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u8:11/8721: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900036ffd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900036ffd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by syz-executor/9265: #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6672 1 lock held by syz-executor/9284: #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6672 1 lock held by syz.8.441/9345: #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 2 locks held by syz.5.447/9417: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7481 Comm: syz.0.196 Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217 Code: 80 d7 03 00 65 8b 15 70 fd 6e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc RSP: 0018:ffffc9000ba6f038 EFLAGS: 00000246 RAX: ffffffff832afb9e RBX: ffff88807d54e000 RCX: ffff88802a47da00 RDX: 0000000000000002 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc9000ba6f230 R08: ffffffff832afb70 R09: 0000000000000000 R10: 00300065006c0069 R11: 006605ff00000020 R12: 1ffff1100faa9c00 R13: dffffc0000000000 R14: ffff88807cf9a910 R15: 0000000000000000 FS: 00007f22529e06c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff754f618a0 CR3: 0000000035c06000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dtSplitRoot+0x8de/0x1930 fs/jfs/jfs_dtree.c:1980 dtSplitUp fs/jfs/jfs_dtree.c:992 [inline] dtInsert+0x12cd/0x6c10 fs/jfs/jfs_dtree.c:870 jfs_create+0x7ba/0xbb0 fs/jfs/namei.c:137 lookup_open fs/namei.c:3595 [inline] open_last_lookups fs/namei.c:3694 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3930 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_creat fs/open.c:1508 [inline] __se_sys_creat fs/open.c:1502 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1502 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2251b7e719 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f22529e0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f2251d35f80 RCX: 00007f2251b7e719 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000e00 RBP: 00007f2251bf139e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2251d35f80 R15: 00007ffe6a8fdcf8