INFO: task syz-executor:5403 blocked for more than 143 seconds. Not tainted 5.15.167-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:19992 pid: 5403 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x293/0xab0 fs/fs-writeback.c:2770 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6e/0x2c0 fs/super.c:448 kill_block_super+0x7a/0xe0 fs/super.c:1425 deactivate_locked_super+0xa0/0x110 fs/super.c:335 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143 task_work_run+0x129/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fbe51070327 RSP: 002b:00007ffcf0ede9a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fbe510e1134 RCX: 00007fbe51070327 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcf0edea60 RBP: 00007ffcf0edea60 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcf0edfae0 R13: 00007fbe510e1134 R14: 0000000000043691 R15: 00007ffcf0edfb20 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:2/154: 3 locks held by kworker/0:2/1291: #0: ffff8880295e2538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000502fd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x1720 net/ipv6/addrconf.c:4113 1 lock held by dhcpcd/3237: #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x12e/0x6d0 net/netlink/af_netlink.c:2348 2 locks held by getty/3326: #0: ffff888029a49098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc9000208e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 4 locks held by kworker/u4:4/3594: 2 locks held by kworker/0:5/3613: #0: ffff888017072138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900030b7d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 4 locks held by kworker/u4:6/3656: 4 locks held by kworker/u4:7/3657: 5 locks held by kworker/u4:10/3695: #0: ffff8880171d5938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90003167d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8da261d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:561 #3: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xc9/0x330 net/ipv4/ip_tunnel.c:1145 #4: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #4: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 3 locks held by kworker/u4:12/3717: 2 locks held by syz-executor/4384: #0: ffff88805cb420e0 (&type->s_umount_key#56){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365 #1: ffff888020bae7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888020bae7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768 2 locks held by syz-executor/5403: #0: ffff8880254f40e0 (&type->s_umount_key#56){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365 #1: ffff8881472d07d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8881472d07d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768 2 locks held by syz-executor/5421: #0: ffff8880758ca0e0 (&type->s_umount_key#56){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365 #1: ffff888020bbc7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888020bbc7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768 2 locks held by syz-executor/5573: #0: ffff8880557aa0e0 (&type->s_umount_key#56){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365 #1: ffff888020ba87d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888020ba87d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768 3 locks held by kworker/u4:18/6608: 1 lock held by syz-executor/6920: #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5615 1 lock held by syz-executor/6955: #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5615 3 locks held by syz-executor/6971: #0: ffffffff8da8f550 (cb_lock){++++}-{3:3} , at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8da8f408 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8da8f408 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x124/0x14a0 net/netlink/genetlink.c:790 #2: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: wg_set_device+0xff/0x2100 drivers/net/wireguard/netlink.c:504 2 locks held by syz.1.752/7177: #0: ffff888073095c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline] #0: ffff888073095c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline] #0: ffff888073095c10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x98/0x230 net/socket.c:1336 #1: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.167-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+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3594 Comm: kworker/u4:4 Not tainted 5.15.167-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: writeback wb_workfn (flush-7:4) RIP: 0010:io_serial_in+0x72/0xb0 drivers/tty/serial/8250/8250_port.c:461 Code: 74 b0 04 fd 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 75 7a 4e fd 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 89 e9 80 e1 07 38 c1 7c ad 48 89 ef RSP: 0018:ffffc90002f85fb8 EFLAGS: 00000006 RAX: 1ffffffff2d71e05 RBX: ffffffff96b8f0c0 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff847ba9f2 R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: ffffffff96b8f080 R13: 1ffffffff2d71e1a R14: 00000000000003f9 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8b2b50bab8 CR3: 000000007f343000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:344 [inline] serial8250_console_write+0x29d/0x1180 drivers/tty/serial/8250/8250_port.c:3359 console_unlock+0xced/0x12b0 kernel/printk/printk.c:2744 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274 _printk+0xd1/0x120 kernel/printk/printk.c:2299 _udf_err+0x137/0x180 fs/udf/super.c:2356 udf_bitmap_new_block fs/udf/balloc.c:357 [inline] udf_new_block+0x1c34/0x21a0 fs/udf/balloc.c:730 inode_getblk fs/udf/inode.c:858 [inline] udf_get_block+0x1a69/0x5360 fs/udf/inode.c:448 __mpage_writepage+0x4f9/0x1c00 fs/mpage.c:564 write_cache_pages+0xa97/0x1160 mm/page-writeback.c:2277 mpage_writepages+0x13c/0x2f0 fs/mpage.c:712 do_writepages+0x481/0x730 mm/page-writeback.c:2386 __writeback_single_inode+0x15b/0xe30 fs/fs-writeback.c:1647 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930 wb_writeback+0x451/0xc50 fs/fs-writeback.c:2104 wb_do_writeback fs/fs-writeback.c:2247 [inline] wb_workfn+0x46c/0x1130 fs/fs-writeback.c:2288 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287