INFO: task syz-executor:15368 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21520 pid:15368 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 wb_wait_for_completion+0x16f/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x1c5/0xa10 fs/fs-writeback.c:2750 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+0x42c/0x4b0 fs/namespace.c:1191 task_work_run+0x1d0/0x260 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+0xee/0x180 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:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb1c819c117 RSP: 002b:00007fff0330c068 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fb1c820471f RCX: 00007fb1c819c117 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff0330c120 RBP: 00007fff0330c120 R08: 00007fff0330d120 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff0330d1b0 R13: 00007fb1c820471f R14: 000000000014b175 R15: 00007fff0330d1f0 Showing all locks held in the system: 4 locks held by kworker/u4:1/11: #0: ffff888019ec7938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffff88807c55e650 (sb_internal#5){.+.+}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline] #2: ffff88807c55e650 (sb_internal#5){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x341/0x1540 fs/xfs/libxfs/xfs_bmap.c:4698 #3: ffff88807429de18 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline] #3: ffff88807429de18 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x368/0x1540 fs/xfs/libxfs/xfs_bmap.c:4698 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2dfb0 (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: ffffffff8cb2e7d0 (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: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 1 lock held by kworker/u4:5/65: 2 locks held by getty/4027: #0: ffff88814d96c098 (&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+0x429/0x1390 drivers/tty/n_tty.c:2198 2 locks held by kworker/0:4/4318: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc900040d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 4 locks held by kworker/u4:15/4668: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc90005fb7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd38f50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:594 #3: ffffffff8cb331c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023 3 locks held by kworker/0:0/8031: #0: ffff88814d5e2938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc9001d507d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xca/0x14f0 net/ipv6/addrconf.c:4131 2 locks held by kworker/1:9/10246: 2 locks held by syz-executor/15368: #0: ffff88807c55e0e0 ( &type->s_umount_key #85 ){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff8881443427d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8881443427d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a9/0xa10 fs/fs-writeback.c:2748 3 locks held by syz-executor/18916: #0: ffffffff8dda5bb0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffffffff8dda59c8 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8dda59c8 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x107/0x790 net/netlink/genetlink.c:848 #2: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: wg_set_device+0xf4/0x1f70 drivers/net/wireguard/netlink.c:504 1 lock held by syz.8.3800/19132: #0: ffff88807c55e0e0 (&type->s_umount_key#85){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 2 locks held by syz.6.3802/19144: #0: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6147 #1: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962 1 lock held by syz.6.3802/19146: #0: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6147 2 locks held by syz.1.3803/19143: #0: ffffffff8dd38f50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8dd45ba8 ( rtnl_mutex ){+.+.}-{3:3} , at: register_nexthop_notifier+0x84/0x240 net/ipv4/nexthop.c:3619 1 lock held by syz.3.3805/19153: #0: ffffffff8dd45ba8 ( rtnl_mutex ){+.+.}-{3:3} , at: do_ip_setsockopt+0x451/0x2ed0 net/ipv4/ip_sockglue.c:954 1 lock held by syz.3.3805/19154: #0: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: do_ip_setsockopt+0x451/0x2ed0 net/ipv4/ip_sockglue.c:954 1 lock held by syz.3.3805/19155: #0: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6147 1 lock held by syz.3.3805/19156: #0: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6147 1 lock held by syz.3.3805/19157: #0: ffffffff8dd45ba8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 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: 17555 Comm: kworker/1:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: xfs-buf/loop4 xfs_buf_ioend_work RIP: 0010:format_decode+0x30c/0x1300 lib/vsprintf.c:-1 Code: c1 7c ac be 08 00 00 00 48 8b 7c 24 08 e8 3c 1a b6 f7 eb 9b 4c 89 74 24 38 48 8b 44 24 10 0f b6 04 18 84 c0 0f 85 01 0d 00 00 <48> 8b 44 24 18 0f b6 04 18 84 c0 0f 85 12 0d 00 00 48 8b 04 24 4c RSP: 0018:ffffc90004467190 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000001 RDX: ffffffff8a1d4305 RSI: ffffffff8e08dc40 RDI: 0000000000000035 RBP: 0000001000000000 R08: ffff888024e43b80 R09: 0000000000000005 R10: 0000000000000030 R11: 0000000000000000 R12: ffffffff8a8cd942 R13: 1ffffffff1519b28 R14: ffffffff8a8cd942 R15: 0000000000000015 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555772d44e8 CR3: 000000002f4d3000 CR4: 00000000003506e0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0xef/0x1c20 lib/vsprintf.c:2757 sprintf+0xe4/0x140 lib/vsprintf.c:3009 print_time kernel/printk/printk.c:1274 [inline] info_print_prefix+0x168/0x360 kernel/printk/printk.c:1300 record_print_text+0x173/0x440 kernel/printk/printk.c:1349 console_emit_next_record+0x598/0xba0 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+0x4b3/0x6a0 kernel/printk/printk.c:2303 _printk+0xda/0x130 kernel/printk/printk.c:2328 __xfs_printk fs/xfs/xfs_message.c:24 [inline] xfs_printk_level+0x1ab/0x2c0 fs/xfs/xfs_message.c:44 xfs_buf_verifier_error+0x166/0x290 fs/xfs/xfs_error.c:435 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+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295