INFO: task syz-executor:5196 blocked for more than 144 seconds. Not tainted 6.1.140-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21856 pid:5196 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 wb_wait_for_completion+0x162/0x280 fs/fs-writeback.c:191 sync_inodes_sb+0x1b8/0x9e0 fs/fs-writeback.c:2739 sync_filesystem+0x16d/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1186 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 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+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcd27f8fc97 RSP: 002b:00007ffd7e35c508 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fcd2801089d RCX: 00007fcd27f8fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd7e35c5c0 RBP: 00007ffd7e35c5c0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd7e35d650 R13: 00007fcd2801089d R14: 000000000010ffd8 R15: 00007ffd7e35d690 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92b4b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92bcd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8c92ab20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92ab20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92ab20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 4 locks held by kworker/0:2/952: 1 lock held by dhcpcd/3918: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2287 2 locks held by getty/4015: #0: ffff88803000c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 ( &ldata->atomic_read_lock ){+.+.}-{3:3} , at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 5 locks held by kworker/u4:16/4509: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004c8fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db27790 ( pernet_ops_rwsem ){++++}-{3:3} , at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8db34428 ( rtnl_mutex ){+.+.}-{3:3} , at: default_device_exit_batch+0xe5/0xa50 net/core/dev.c:11477 #4: ffffffff8c9307f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #4: ffffffff8c9307f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 4 locks held by kworker/u4:17/4524: #0: ffff88801aea9938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000525fd00 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8c91eda0 ( console_lock){+.+.}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline] console_lock){+.+.}-{0:0}, at: xfs_bmapi_convert_delalloc+0x2fd/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 #3: ffff88805125f558 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline] #3: ffff88805125f558 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x329/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 2 locks held by syz-executor/5196: #0: ffff8880289dc0e0 (&type->s_umount_key#62 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff888024d287d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888024d287d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x19c/0x9e0 fs/fs-writeback.c:2737 3 locks held by kworker/u4:23/5852: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004717d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db34428 ( rtnl_mutex ){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 2 locks held by kworker/1:18/6199: 2 locks held by kworker/1:4/16324: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000e557d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/0:1/16485: #0: ffff88802f7d6d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000ef27d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4137 1 lock held by syz-executor/17607: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492 1 lock held by syz-executor/17863: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 1 lock held by syz-executor/18007: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 1 lock held by syz.9.2794/18011: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104 1 lock held by syz.9.2794/18017: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x567/0xea0 net/core/dev_ioctl.c:587 1 lock held by syz.2.2796/18025: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: do_ip_setsockopt+0x425/0x2d60 net/ipv4/ip_sockglue.c:954 1 lock held by syz.2.2796/18026: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: do_ip_setsockopt+0x425/0x2d60 net/ipv4/ip_sockglue.c:954 1 lock held by syz.7.2799/18034: #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db34428 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.140-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 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: 16324 Comm: kworker/1:4 Not tainted 6.1.140-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: xfs-buf/loop8 xfs_buf_ioend_work RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:215 Code: 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 50 ab 7d 0c 48 89 de 5b e9 07 ad 50 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d 24 98 81 7e 65 8b 15 25 98 81 7e 81 e2 00 01 ff 00 74 RSP: 0018:ffffc9000e557038 EFLAGS: 00000246 RAX: ffffffff8a007583 RBX: 000000000000000a RCX: 0000000000000000 RDX: ffff88802ba70000 RSI: 000000000000000a RDI: 000000000000000a RBP: ffffc9000e557160 R08: dffffc0000000000 R09: ffffc9000e5570c0 R10: fffff52001caae1b R11: 1ffff92001caae18 R12: 0000000000ffff0a R13: 00000000000004f9 R14: ffffc9000e557441 R15: 000000000000000a FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555685655c8 CR3: 000000000c68e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: number+0x2f3/0xf70 lib/vsprintf.c:508 vsnprintf+0x10fe/0x1a00 lib/vsprintf.c:2871 sprintf+0xd6/0x120 lib/vsprintf.c:3009 print_time kernel/printk/printk.c:1274 [inline] info_print_prefix+0x152/0x300 kernel/printk/printk.c:1300 record_print_text+0x151/0x420 kernel/printk/printk.c:1349 console_emit_next_record+0x65d/0xc90 kernel/printk/printk.c:2760 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303 _printk+0xcc/0x110 kernel/printk/printk.c:2328 print_hex_dump+0x1a5/0x260 lib/hexdump.c:285 xfs_hex_dump+0x39/0x50 fs/xfs/xfs_message.c:110 xfs_buf_verifier_error+0x1c8/0x290 fs/xfs/xfs_error.c:441 xfs_allocbt_read_verify+0x53/0xd0 fs/xfs/libxfs/xfs_alloc_btree.c:-1 xfs_buf_ioend+0x27a/0x780 fs/xfs/xfs_buf.c:1303 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295