syzbot

INFO: task syz-executor:9878 blocked for more than 143 seconds.
      Not tainted 6.11.0-syzkaller-07341-gbaeb9a7d8b60 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:20992 pid:9878  tgid:9878  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1893/0x4b50 kernel/sched/core.c:6607
 __schedule_loop kernel/sched/core.c:6684 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6699
 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
 kthread_stop+0x19e/0x640 kernel/kthread.c:710
 ext4_stop_mmpd+0x47/0xb0 fs/ext4/mmp.c:261
 ext4_put_super+0x753/0xd50 fs/ext4/super.c:1365
 generic_shutdown_super+0x13b/0x2d0 fs/super.c:642
 kill_block_super+0x44/0x90 fs/super.c:1696
 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7289
 deactivate_locked_super+0xc6/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
 task_work_run+0x251/0x310 kernel/task_work.c:228
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9862f7f227
RSP: 002b:00007fff41632008 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f9862f7f227
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff416320c0
RBP: 00007fff416320c0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff41633140
R13: 00007f9862ff0a14 R14: 00000000000b7ae7 R15: 00007fff41633180
 </TASK>
INFO: task kmmpd-loop2:11020 blocked for more than 143 seconds.
      Not tainted 6.11.0-syzkaller-07341-gbaeb9a7d8b60 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kmmpd-loop2     state:D stack:27472 pid:11020 tgid:11020 ppid:2      flags:0x00024000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5264 [inline]
 __schedule+0x1893/0x4b50 kernel/sched/core.c:6607
 __schedule_loop kernel/sched/core.c:6684 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6699
 percpu_rwsem_wait+0x3c2/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xee/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 __sb_start_write include/linux/fs.h:1715 [inline]
 sb_start_write include/linux/fs.h:1851 [inline]
 write_mmp_block+0x2f2/0x3a0 fs/ext4/mmp.c:66
 kmmpd+0x26d/0xaa0 fs/ext4/mmp.c:246
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/11:
 #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90000107d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000107d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
1 lock held by khungtaskd/30:
 #0: ffffffff8e9389e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e9389e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e9389e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701
3 locks held by kworker/u8:5/81:
4 locks held by kworker/0:2/932:
 #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90003d7fd00 ((delayed_fput_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90003d7fd00 ((delayed_fput_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff88805b9bf408 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #2: ffff88805b9bf408 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #2: ffff88805b9bf408 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1427
 #3: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: raw_release+0x1b8/0x8b0 net/can/raw.c:415
2 locks held by dhcpcd/4886:
 #0: ffff888079b9b6c8 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2404
 #1: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #1: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6505
2 locks held by getty/4969:
 #0: ffff8880327710a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
5 locks held by kworker/u8:7/5292:
 #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc9000389fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc9000389fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcbd010 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580
 #3: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: cleanup_net+0x6af/0xcc0 net/core/net_namespace.c:616
 #4: ffffffff8e93df78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #4: ffffffff8e93df78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976
1 lock held by syz-executor/9878:
 #0: ffff888065c3c0e0 (&type->s_umount_key#33){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888065c3c0e0 (&type->s_umount_key#33){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888065c3c0e0 (&type->s_umount_key#33){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505
3 locks held by kworker/u8:19/10555:
 #0: ffff88802d7c4948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88802d7c4948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90003c67d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90003c67d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196
1 lock held by kmmpd-loop2/11020:
 #0: ffff888065c3c420 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x26d/0xaa0 fs/ext4/mmp.c:246
3 locks held by kworker/0:4/11260:
 #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90003fd7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90003fd7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by syz-executor/11556:
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517
1 lock held by syz-executor/11720:
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
1 lock held by syz-executor/11842:
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
7 locks held by syz-executor/11844:
 #0: ffff88802dcca420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2930 [inline]
 #0: ffff88802dcca420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679
 #1: ffff888054cc3088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff8880278e33c8 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f5676c8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
 #4: ffff88805ca410e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #4: ffff88805ca410e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline]
 #4: ffff88805ca410e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1292
 #5: ffff88804d9d8250 (&devlink->lock_key#50){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672
 #6: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773
2 locks held by syz-executor/11987:
 #0: ffffffff8fcbd010 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490
 #1: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x20e/0x720 net/ipv4/ip_tunnel.c:1159
1 lock held by syz.2.1198/12022:
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
1 lock held by syz.1.1201/12031:
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
 #0: ffffffff8fcc9b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-07341-gbaeb9a7d8b60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 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+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4661 Comm: klogd Not tainted 6.11.0-syzkaller-07341-gbaeb9a7d8b60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:preempt_count_add+0x34/0x190 kernel/sched/core.c:5724
Code: fb 48 c7 c0 00 69 3a 9a 48 c1 e8 03 49 bf 00 00 00 00 00 fc ff df 42 0f b6 04 38 84 c0 0f 85 ed 00 00 00 83 3d bc 51 d7 18 00 <75> 07 65 8b 05 7b bf a0 7e 65 01 1d 74 bf a0 7e 48 c7 c0 00 69 3a
RSP: 0018:ffffc900052f74b0 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff9a3a6903
RDX: 0000000000000000 RSI: ffffffff8c60dce0 RDI: 0000000000000001
RBP: ffffc900052f7630 R08: ffffffff901c5aaf R09: 1ffffffff2038b55
R10: dffffc0000000000 R11: fffffbfff2038b56 R12: ffff88807ea4a244
R13: ffff88807ea4a248 R14: 1ffff1100fd49449 R15: dffffc0000000000
FS:  00007f6b18531380(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33217ff8 CR3: 0000000032148000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_lock include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock+0x12/0x40 kernel/locking/spinlock.c:154
 rcu_note_context_switch+0x2a9/0xff0 kernel/rcu/tree_plugin.h:337
 __schedule+0x348/0x4b50 kernel/sched/core.c:6489
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6786
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6810
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x130/0x140 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock+0x18c/0x1e0 kernel/sched/wait.c:108
 sock_def_readable+0x20f/0x5b0 net/core/sock.c:3442
 unix_dgram_sendmsg+0x1495/0x1f80 net/unix/af_unix.c:2167
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 __sys_sendto+0x398/0x4f0 net/socket.c:2210
 __do_sys_sendto net/socket.c:2222 [inline]
 __se_sys_sendto net/socket.c:2218 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2218
 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: 0033:0x7f6b186939b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffed6a5b588 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f6b186939b5
RDX: 000000000000004a RSI: 000056474656cac0 RDI: 0000000000000003
RBP: 0000564746564910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007f6b18821212 R14: 00007ffed6a5b688 R15: 0000000000000000
 </TASK>