syzbot

INFO: task syz.1.102:6269 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.102       state:D stack:24656 pid:6269  tgid:6265  ppid:5734   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5315 [inline]
 __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675
 __schedule_loop kernel/sched/core.c:6752 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6767
 jfs_flush_journal+0x72c/0xec0 fs/jfs/jfs_logmgr.c:1564
 jfs_sync_fs+0x80/0xa0 fs/jfs/super.c:684
 sync_filesystem+0x1c8/0x230 fs/sync.c:66
 jfs_remount+0x136/0x6b0 fs/jfs/super.c:432
 reconfigure_super+0x445/0x880 fs/super.c:1083
 do_remount fs/namespace.c:3047 [inline]
 path_mount+0xc22/0xfa0 fs/namespace.c:3826
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbe20d7f79a
RSP: 002b:00007fbe21b07e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fbe21b07ef0 RCX: 00007fbe20d7f79a
RDX: 0000000020000180 RSI: 0000000020000100 RDI: 0000000000000000
RBP: 0000000020000180 R08: 00007fbe21b07ef0 R09: 0000000001a4243c
R10: 0000000001a4243c R11: 0000000000000246 R12: 0000000020000100
R13: 00007fbe21b07eb0 R14: 0000000000000000 R15: 0000000020000600
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/12:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90000117d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000117d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff9a5edc78 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed lib/debugobjects.c:978 [inline]
 #2: ffffffff9a5edc78 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_check_no_obj_freed+0x234/0x580 lib/debugobjects.c:1019
1 lock held by khungtaskd/30:
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
3 locks held by kworker/1:2/2633:
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90009a17d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90009a17d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
3 locks held by kworker/u8:7/3032:
 #0: ffff88802dd7b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88802dd7b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc9000a047d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc9000a047d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196
1 lock held by dhcpcd/4887:
 #0: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1aa0 net/ipv4/devinet.c:1097
2 locks held by getty/4974:
 #0: ffff88814c36d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:4/5223:
 #0: ffff88802f8a5148 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88802f8a5148 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90003e57d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90003e57d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff888062b00d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:327
3 locks held by kworker/0:5/5272:
3 locks held by kworker/0:6/5273:
1 lock held by syz.1.102/6269:
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: do_remount fs/namespace.c:3044 [inline]
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: path_mount+0xbdb/0xfa0 fs/namespace.c:3826
3 locks held by kworker/u8:13/6488:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90004357d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90004357d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
1 lock held by syz.3.125/6544:
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
1 lock held by syz.1.146/6809:
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
1 lock held by syz.3.150/6826:
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
7 locks held by syz-executor/7943:
1 lock held by syz.1.264/7947:
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88804bed40e0 (&type->s_umount_key#89){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
1 lock held by syz-executor/8120:
 #0: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
1 lock held by syz-executor/8243:
 #0: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
2 locks held by syz.4.322/8379:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7943 Comm: syz-executor Not tainted 6.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:406
Code: a0 e7 53 fc 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 d1 75 ba fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c
RSP: 0018:ffffc90004c5e698 EFLAGS: 00000006
RAX: 1ffffffff34db905 RBX: ffffffff9a6dcc00 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff8540fe76 R09: fffff5200098bcb4
R10: dffffc0000000000 R11: ffffffff8540fe30 R12: dffffc0000000000
R13: 1ffff9200098bcf0 R14: 00000000000003f9 R15: dffffc0000000000
FS:  000055555f60b500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc1dc656de CR3: 000000006a7ba000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 serial_port_in include/linux/serial_core.h:787 [inline]
 serial8250_console_write+0x4de/0x1ed0 drivers/tty/serial/8250/8250_port.c:3357
 console_emit_next_record kernel/printk/printk.c:3092 [inline]
 console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3180
 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
 console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279
 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407
 _printk+0xd5/0x120 kernel/printk/printk.c:2432
 batadv_hardif_activate_interface+0x16e/0x3c0 net/batman-adv/hard-interface.c:675
 batadv_hard_if_event+0x354/0x1620 net/batman-adv/hard-interface.c:977
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 __dev_notify_flags+0x207/0x400
 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8918
 do_setlink+0xcd0/0x41f0 net/core/rtnetlink.c:2900
 __rtnl_newlink net/core/rtnetlink.c:3696 [inline]
 rtnl_newlink+0x180d/0x20a0 net/core/rtnetlink.c:3743
 rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:744
 __sys_sendto+0x39b/0x4f0 net/socket.c:2209
 __do_sys_sendto net/socket.c:2221 [inline]
 __se_sys_sendto net/socket.c:2217 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2217
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8035b7fe8c
Code: 2a 5a 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5a 02 00 48 8b
RSP: 002b:00007fff699bb560 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f8036864620 RCX: 00007f8035b7fe8c
RDX: 000000000000002c RSI: 00007f8036864670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007fff699bb5b4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f8036864670 R15: 0000000000000000
 </TASK>