INFO: task syz-executor:4253 blocked for more than 144 seconds. Not tainted 6.1.114-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21248 pid:4253 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f26ce77fa47 RSP: 002b:00007ffd27352738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f26ce7f11cc RCX: 00007f26ce77fa47 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd273527f0 RBP: 00007ffd273527f0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd27353870 R13: 00007f26ce7f11cc R14: 00000000000161ce R15: 00007ffd273538b0 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b1d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32b9d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 2 locks held by getty/4009: #0: ffff88814d368098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900032462f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 3 locks held by kworker/0:3/4239: #0: ffff88814c1b3938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90003d2fd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4fafa8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16b0 net/ipv6/addrconf.c:4115 2 locks held by syz-executor/4253: #0: ffff8880717140e0 (&type->s_umount_key#85){+.+.}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffff888142bae7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] ffff888142bae7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737 2 locks held by kworker/0:8/4327: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90003f4fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 5 locks held by kworker/u4:10/4481: #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90004c77d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4eec50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:566 #3: ffffffff8e4fafa8 ( rtnl_mutex ){+.+.}-{3:3} , at: ip_tunnel_delete_nets+0xc9/0x330 net/ipv4/ip_tunnel.c:1148 #4: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962 7 locks held by kworker/u4:11/4491: 3 locks held by kworker/1:9/4542: #0: ffff88814c1b3938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90005597d20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4fafa8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16b0 net/ipv6/addrconf.c:4115 1 lock held by syz-executor/5478: #0: ffffffff8e4fafa8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8e4fafa8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6147 1 lock held by syz-executor/5594: #0: ffffffff8e4fafa8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8e4fafa8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6147 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.114-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4491 Comm: kworker/u4:11 Not tainted 6.1.114-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: writeback wb_workfn (flush-7:3) RIP: 0010:__lock_acquire+0x90/0x1f80 Code: c1 e8 03 80 3c 10 00 74 12 4c 89 f7 e8 49 75 77 00 48 ba 00 00 00 00 00 fc ff df 48 c7 c0 20 01 da 90 49 39 06 75 03 45 31 ff <89> 5c 24 3c 83 fd 01 77 2e 89 e8 49 8d 5c c6 08 48 89 d8 48 c1 e8 RSP: 0018:ffffc900051b6140 EFLAGS: 00000087 RAX: ffffffff90da0120 RBX: 0000000000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff8d207220 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: ffff88802c7e1dc0 R14: ffffffff8d207220 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9c3de78866 CR3: 000000007e296000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 console_trylock_spinning kernel/printk/printk.c:1948 [inline] vprintk_emit+0x513/0x740 kernel/printk/printk.c:2302 _printk+0xd1/0x111 kernel/printk/printk.c:2328 _udf_err+0x137/0x180 fs/udf/super.c:2353 udf_bitmap_new_block fs/udf/balloc.c:357 [inline] udf_new_block+0x1bb4/0x2130 fs/udf/balloc.c:730 inode_getblk fs/udf/inode.c:769 [inline] udf_get_block+0x1a69/0x5360 fs/udf/inode.c:359 __mpage_writepage+0x40d/0x1930 fs/mpage.c:533 write_cache_pages+0x92e/0x15c0 mm/page-writeback.c:2382 mpage_writepages+0x103/0x1d0 fs/mpage.c:664 do_writepages+0x3a2/0x670 mm/page-writeback.c:2491 __writeback_single_inode+0x15d/0x11e0 fs/fs-writeback.c:1612 writeback_sb_inodes+0xc2b/0x1b20 fs/fs-writeback.c:1903 wb_writeback+0x49d/0xe10 fs/fs-writeback.c:2077 wb_do_writeback fs/fs-writeback.c:2220 [inline] wb_workfn+0x427/0x1020 fs/fs-writeback.c:2260 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295