INFO: task syz-executor:4270 blocked for more than 144 seconds. Not tainted 6.1.147-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21984 pid:4270 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 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:1182 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: 0033:0x7f071118ff17 RSP: 002b:00007ffee873fd08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f0711211c05 RCX: 00007f071118ff17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffee873fdc0 RBP: 00007ffee873fdc0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffee8740e50 R13: 00007f0711211c05 R14: 000000000001c8f0 R15: 00007ffee8740e90 Showing all locks held in the system: 3 locks held by kworker/0:0/7: #0: ffff88802fa86138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900000c7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd401e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4132 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b7b0 (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: ffffffff8cb2bfd0 (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: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4031: #0: ffff888030774098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 2 locks held by syz-executor/4270: #0: ffff88807899e0e0 (&type->s_umount_key#64){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff8880245787d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8880245787d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x19c/0x9e0 fs/fs-writeback.c:2737 5 locks held by kworker/0:7/4345: #0: ffff8880b8e3aa98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffff8880b8e27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999 #2: ffff888058b0b538 (&idev->mc_lock){+.+.}-{3:3}, at: mld_ifc_work+0x29/0xb40 net/ipv6/mcast.c:2658 #3: ffffffff96ebf158 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x6a/0x490 lib/debugobjects.c:698 #4: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #4: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #4: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: ip6_finish_output2+0x593/0x1590 net/ipv6/ip6_output.c:123 2 locks held by kworker/1:7/4381: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900049dfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/1:9/4473: #0: ffff88802fa86138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004e1fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd401e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4132 3 locks held by kworker/1:15/4481: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004e7fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff8880595ef240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26b/0x32b0 drivers/net/netdevsim/fib.c:1491 8 locks held by kworker/u4:10/4557: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000507fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd33550 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8dd401e8 ( rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x51/0x290 net/mac80211/main.c:1471 #4: ffff8880555607c8 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:5639 [inline] ffff8880555607c8 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: cfg80211_netdev_notifier_call+0x496/0x13e0 net/wireless/core.c:1511 #5: ffff88805559cd40 (&wdev->mtx){+.+.}-{3:3}, at: wdev_lock net/wireless/core.h:231 [inline] #5: ffff88805559cd40 (&wdev->mtx){+.+.}-{3:3}, at: cfg80211_leave net/wireless/core.c:1349 [inline] #5: ffff88805559cd40 (&wdev->mtx){+.+.}-{3:3}, at: cfg80211_netdev_notifier_call+0x4ad/0x13e0 net/wireless/core.c:1512 #6: ffff888055561780 (&local->sta_mtx){+.+.}-{3:3}, at: __sta_info_flush+0x17a/0x450 net/mac80211/sta_info.c:1442 #7: ffffffff8cb30af8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #7: ffffffff8cb30af8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 4 locks held by kworker/u4:11/4597: #0: ffff888144e4e138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000512fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88807899e650 (sb_internal#3){.+.+}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline] #2: ffff88807899e650 (sb_internal#3){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x2fd/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 #3: ffff8880565b8118 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline] #3: ffff8880565b8118 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x329/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 3 locks held by kworker/0:17/5038: 3 locks held by kworker/u4:21/5459: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000c43fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd401e8 (rtnl_mutex ){+.+.}-{3:3} , at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 1 lock held by syz-executor/5714: #0: ffffffff8dd401e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd401e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 1 lock held by syz-executor/5736: #0: ffffffff8dd401e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd401e8 (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 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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: 4315 Comm: kworker/1:4 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: xfs-buf/loop4 xfs_buf_ioend_work RIP: 0010:io_serial_out+0x78/0xb0 drivers/tty/serial/8250/8250_port.c:468 Code: 21 0a fd 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 e0 3d 5a fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 44 89 f9 80 e1 07 38 c1 7c aa 4c 89 ff RSP: 0018:ffffc90004367270 EFLAGS: 00000002 RAX: 0000000000000020 RBX: 0000000000000020 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020 RBP: 00000000000003f8 R08: dffffc0000000000 R09: ffffed100482a047 R10: ffffed100482a047 R11: 1ffff1100482a046 R12: dffffc0000000000 R13: ffffffff96c26de2 R14: ffffffff96f6b480 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd306985286 CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:122 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline] serial8250_console_write+0x10fa/0x17a0 drivers/tty/serial/8250/8250_port.c:3474 call_console_driver kernel/printk/printk.c:1977 [inline] console_emit_next_record+0x947/0xc90 kernel/printk/printk.c:2777 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_agf_read_verify+0x1cd/0x250 fs/xfs/libxfs/xfs_alloc.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