INFO: task syz.5.1374:11977 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1374 state:D stack:28904 pid:11977 tgid:11934 ppid:5833 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 inode_lock include/linux/fs.h:980 [inline] vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x274/0x600 fs/xattr.c:665 path_setxattrat+0x364/0x3a0 fs/xattr.c:713 __do_sys_setxattr fs/xattr.c:747 [inline] __se_sys_setxattr fs/xattr.c:743 [inline] __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:743 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fefecd8f6c9 RSP: 002b:00007fefeaff6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc RAX: ffffffffffffffda RBX: 00007fefecfe6180 RCX: 00007fefecd8f6c9 RDX: 000020000000a440 RSI: 0000200000000040 RDI: 0000200000000000 RBP: 00007fefece11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000090f R11: 0000000000000246 R12: 0000000000000000 R13: 00007fefecfe6218 R14: 00007fefecfe6180 R15: 00007ffdbfc642a8 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88801a069948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a069948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000127ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000127ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by ksoftirqd/1/23: #0: ffff8880b883a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646 #1: ffff8880b8924048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 1 lock held by khungtaskd/31: #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by klogd/5183: #0: ffff8880b883a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646 1 lock held by dhcpcd/5489: #0: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1120 2 locks held by getty/5584: #0: ffff88814d38f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:4/5926: #0: ffff88801a051948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a051948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90005197ba0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90005197ba0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/0:5/5927: 5 locks held by kworker/u8:12/6040: #0: ffff88801aed7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801aed7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000b347ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000b347ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f2bed70 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:248 #4: ffffffff8df43178 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #4: ffffffff8df43178 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 4 locks held by syz.5.1374/11935: #0: ffff88802a73e420 (sb_writers#32){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88804c6dce30 (&sb->s_type->i_mutex_key#36){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff88804c6dce30 (&sb->s_type->i_mutex_key#36){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 #2: ffff88802a73e610 (sb_internal#4){.+.+}-{0:0}, at: xfs_trans_alloc+0xd7/0x980 fs/xfs/xfs_trans.c:256 #3: ffff88804c6dcc18 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_trans_alloc_inode+0x161/0x4a0 fs/xfs/xfs_trans.c:1082 2 locks held by syz.5.1374/11977: #0: ffff88802a73e420 (sb_writers#32){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88804c6dce30 (&sb->s_type->i_mutex_key#36){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff88804c6dce30 (&sb->s_type->i_mutex_key#36){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 3 locks held by kworker/u8:14/12214: 1 lock held by syz-executor/12840: #0: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz-executor/12921: #0: ffffffff8f7ed298 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f7ed298 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8f7ed298 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 1 lock held by syz-executor/12967: #0: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1df0 drivers/net/tun.c:3078 2 locks held by syz.0.1619/13049: #0: ffffffff8f7d2f08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f7d2f08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8f7d2f08 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2cbc08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6040 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net RIP: 0010:rdtsc_ordered arch/x86/include/asm/tsc.h:57 [inline] RIP: 0010:delay_tsc+0x71/0xc0 arch/x86/lib/delay.c:72 Code: 00 00 e8 82 ba 4a f6 65 8b 05 db 19 29 07 85 c0 74 1c f3 90 bf 01 00 00 00 e8 bb b8 4a f6 e8 96 64 01 00 39 c5 75 0e 0f 01 f9 <66> 90 eb bd e8 a6 01 ee f5 eb dd 4c 29 fb e8 7c 64 01 00 89 c5 0f RSP: 0018:ffffc9000b346ed0 EFLAGS: 00000046 RAX: 0000000068d4ea1e RBX: 0000000000000993 RCX: 0000000000000001 RDX: 0000000000000208 RSI: ffffffff8bbf08c0 RDI: ffffffff8bbf0880 RBP: 0000000000000001 R08: ffff888023c70237 R09: 1ffff1100478e046 R10: dffffc0000000000 R11: ffffffff8b453600 R12: 1ffffffff335da36 R13: 00000000ffffffff R14: 0000020868d4e834 R15: 0000000000000157 FS: 0000000000000000(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b169b4198 CR3: 0000000078206000 CR4: 0000000000350ef0 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:1967 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3111 [inline] console_flush_all+0x6f3/0xb10 kernel/printk/printk.c:3199 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3298 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423 _printk+0xcf/0x120 kernel/printk/printk.c:2448 netdev_info+0x10a/0x160 net/core/dev.c:12771 bond_uninit+0x16e/0x2d0 drivers/net/bonding/bond_main.c:6046 unregister_netdevice_many_notify+0x1cde/0x2390 net/core/dev.c:12305 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248 cleanup_net+0x4d8/0x820 net/core/net_namespace.c:695 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245