INFO: task kworker/u8:2:36 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:2 state:D stack:21400 pid:36 tgid:36 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 io_schedule+0x81/0xe0 kernel/sched/core.c:7742 f2fs_balance_fs+0x4b4/0x780 fs/f2fs/segment.c:444 f2fs_write_inode+0x49d/0x870 fs/f2fs/inode.c:812 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.2.1099:14803 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1099 state:D stack:25272 pid:14803 tgid:14802 ppid:12306 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 __writeback_inodes_sb_nr+0x1f6/0x250 fs/fs-writeback.c:2747 sync_filesystem+0xa3/0x230 fs/sync.c:54 freeze_super+0x4f9/0xeb0 fs/super.c:2052 fs_bdev_freeze+0x19f/0x310 fs/super.c:1484 bdev_freeze+0xd5/0x220 block/bdev.c:298 f2fs_do_shutdown+0x23d/0x5c0 fs/f2fs/file.c:2367 f2fs_ioc_shutdown fs/f2fs/file.c:2459 [inline] __f2fs_ioctl+0x3de9/0xae80 fs/f2fs/file.c:4558 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa7c818e969 RSP: 002b:00007fa7c90a9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa7c83b5fa0 RCX: 00007fa7c818e969 RDX: 0000200000000240 RSI: 000000008004587d RDI: 0000000000000008 RBP: 00007fa7c8210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa7c83b5fa0 R15: 00007ffeb6555998 INFO: task syz.2.1099:14856 blocked for more than 144 seconds. Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1099 state:D stack:26360 pid:14856 tgid:14802 ppid:12306 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 percpu_rwsem_wait+0x2ab/0x300 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xe3/0x120 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:66 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_write+0x185/0x1c0 include/linux/fs.h:1919 mnt_want_write+0x41/0x90 fs/namespace.c:556 open_last_lookups fs/namei.c:3789 [inline] path_openat+0x85d/0x3830 fs/namei.c:4036 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_creat fs/open.c:1522 [inline] __se_sys_creat fs/open.c:1516 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1516 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa7c818e969 RSP: 002b:00007fa7c9088038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fa7c83b6080 RCX: 00007fa7c818e969 RDX: 0000000000000000 RSI: 000000000000014c RDI: 0000200000000100 RBP: 00007fa7c8210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa7c83b6080 R15: 00007ffeb6555998 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:2/36: #0: ffff888144a8a948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888144a8a948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000ad7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000ad7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 2 locks held by getty/5585: #0: ffff8880345c10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz.2.1099/14803: #0: ffff888148cfddb0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff888028a48420 (sb_writers#19){++++}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline] #1: ffff888028a48420 (sb_writers#19){++++}-{0:0}, at: freeze_super+0x4c2/0xeb0 fs/super.c:2044 #2: ffff888028a480e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #2: ffff888028a480e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #2: ffff888028a480e0 (&type->s_umount_key#74){++++}-{4:4}, at: freeze_super+0x4ca/0xeb0 fs/super.c:2045 #3: ffff888028a48518 (sb_pagefaults#6){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline] #3: ffff888028a48518 (sb_pagefaults#6){+.+.}-{0:0}, at: freeze_super+0x4f1/0xeb0 fs/super.c:2049 1 lock held by syz.2.1099/14856: #0: ffff888028a48420 (sb_writers#19){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 1 lock held by syz.5.1140/15168: #0: ffff888028a480e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888028a480e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 1 lock held by syz.6.1139/15420: #0: ffff888028a480e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888028a480e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 1 lock held by dhcpcd/17557: #0: ffff88805917ca08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #0: ffff88805917ca08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88805917ca08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 1 lock held by dhcpcd/17558: #0: ffff88803cf36258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff88803cf36258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 2 locks held by dhcpcd/17559: #0: ffff88807d208258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff88807d208258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 #1: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #1: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 1 lock held by dhcpcd/17560: #0: ffff888077504258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff888077504258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 1 lock held by dhcpcd/17561: #0: ffff88806e9d2258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff88806e9d2258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 1 lock held by dhcpcd/17562: #0: ffff8880684f0258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff8880684f0258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 1 lock held by dhcpcd/17563: #0: ffff88806e9d0258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff88806e9d0258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 1 lock held by dhcpcd/17564: #0: ffff88805c614258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff88805c614258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 1 lock held by dhcpcd/17565: #0: ffff88807e9c8258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff88807e9c8258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 1 lock held by dhcpcd/17566: #0: ffff8880294f0258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff8880294f0258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 1 lock held by dhcpcd/17567: #0: ffff88805c612258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff88805c612258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 1 lock held by dhcpcd/17568: #0: ffff88803aef0258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] #0: ffff88803aef0258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #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:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 14854 Comm: f2fs_gc-7:2 Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217 Code: 5b e9 93 40 55 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 50 72 92 <65> 8b 15 18 5f b2 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc9000b697b90 EFLAGS: 00000206 RAX: ffffffff818dcd39 RBX: ffff88802b5fbc00 RCX: ffff88802b5fbc00 RDX: ffff88802b5fbc00 RSI: 0000000000200000 RDI: 0000000000000000 RBP: 0000000000200000 R08: ffff8880329c0c07 R09: 1ffff11006538180 R10: dffffc0000000000 R11: ffffed1006538181 R12: ffff8880234e4000 R13: dffffc0000000000 R14: ffff88802b5fbc2c R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881260fb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005618260920b8 CR3: 0000000032618000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: to_kthread kernel/kthread.c:84 [inline] kthread_should_stop+0x59/0xf0 kernel/kthread.c:169 gc_thread_func+0xaaf/0x2b30 fs/f2fs/gc.c:185 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245