INFO: task syz.4.388:7005 blocked for more than 146 seconds.
      Not tainted 6.12.0-rc3-next-20241015-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.388       state:D stack:23512 pid:7005  tgid:7004  ppid:5797   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x18af/0x4bd0 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839
 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578
 mmap_write_lock include/linux/mmap_lock.h:106 [inline]
 exit_mmap+0x2bd/0xc40 mm/mmap.c:1886
 __mmput+0x115/0x390 kernel/fork.c:1346
 exit_mm+0x220/0x310 kernel/exit.c:570
 do_exit+0x9b2/0x28e0 kernel/exit.c:925
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 get_signal+0x16a3/0x1740 kernel/signal.c:2917
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f79ecf7dff9
RSP: 002b:00007f79ede460e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f79ed135f88 RCX: 00007f79ecf7dff9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f79ed135f8c
RBP: 00007f79ed135f80 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 00007f79ed135f8c
R13: 0000000000000000 R14: 00007ffe9a011120 R15: 00007ffe9a011208
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/12:
1 lock held by khungtaskd/30:
 #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
5 locks held by kworker/u8:2/35:
 #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90000ab7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000ab7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fccf910 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:587
 #3: ffffffff8fcdc488 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:11942
 #4: ffffffff8e93f3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #4: ffffffff8e93f3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976
3 locks held by kworker/u8:5/1060:
 #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: ffffc90003c77d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90003c77d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcdc488 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
1 lock held by dhcpcd/4905:
2 locks held by getty/4987:
 #0: ffff8880326a20a0 (&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
1 lock held by dhcpcd/5050:
1 lock held by syz.4.388/7005:
 #0: ffff88807e1a4418 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:106 [inline]
 #0: ffff88807e1a4418 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x2bd/0xc40 mm/mmap.c:1886
1 lock held by syz-executor/7564:
1 lock held by syz-executor/7565:
1 lock held by syz-executor/7970:
1 lock held by syz.4.662/7996:
1 lock held by syz.4.662/7997:
1 lock held by syz.4.662/8020:
1 lock held by syz.1.664/8004:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc3-next-20241015-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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 101 PID: 4904 Comm: dhcpcd Not tainted 6.12.0-rc3-next-20241015-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:314
Code: 44 0a 20 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 <65> 48 8b 14 25 c0 d3 03 00 65 8b 05 d0 ed 6e 7e 25 00 01 ff 00 74
RSP: 0018:ffffc9000316f918 EFLAGS: 00000293
RAX: ffffffff8157319d RBX: 0000000000000001 RCX: ffff88802dd7da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000030
RBP: ffffc9000316faf0 R08: ffffffff815731be R09: ffffffff8157302e
R10: 0000000000000002 R11: ffff88802dd7da00 R12: ffffc9000316fca0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f0606e40740(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d2a09ad600 CR3: 0000000021b6e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 wait_consider_task+0x29e/0x2e60 kernel/exit.c:1440
 do_wait_thread kernel/exit.c:1539 [inline]
 __do_wait+0x1b0/0x850 kernel/exit.c:1657
 do_wait+0x1e9/0x560 kernel/exit.c:1691
 kernel_wait4+0x2a7/0x3e0 kernel/exit.c:1850
 __do_sys_wait4 kernel/exit.c:1878 [inline]
 __se_sys_wait4 kernel/exit.c:1874 [inline]
 __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1874
 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: 0033:0x7f0606ef0476
Code: 10 00 00 00 48 89 d1 89 f2 48 89 fe 83 cf ff e9 00 00 00 00 49 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 73 48 8b 15 83 49 0f 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffcb3711df8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 000055d2bae11e20 RCX: 00007f0606ef0476
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00000000ffffffff
RBP: 00007ffcb3711ef8 R08: 0000000000000008 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 044e806f841adc0d
R13: 000055d2a09ad610 R14: 00000000ffffffff R15: 0000000000000000
 </TASK>