syzbot

INFO: task syz-executor.5:5019 blocked for more than 143 seconds.
      Not tainted 6.4.0-rc4-syzkaller-00047-gafead42fdfca #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:20856 pid:5019  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5343 [inline]
 __schedule+0x187b/0x4900 kernel/sched/core.c:6669
 schedule+0xc3/0x180 kernel/sched/core.c:6745
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804
 rwsem_down_write_slowpath+0xedd/0x13a0 kernel/locking/rwsem.c:1178
 __down_write_common+0x1aa/0x200 kernel/locking/rwsem.c:1306
 deactivate_super+0xad/0xf0 fs/super.c:361
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1177
 task_work_run+0x24a/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f187768d5d7
RSP: 002b:00007fff7ba1bc68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f187768d5d7
RDX: 00007fff7ba1bd3c RSI: 000000000000000a RDI: 00007fff7ba1bd30
RBP: 00007fff7ba1bd30 R08: 00000000ffffffff R09: 00007fff7ba1bb00
R10: 0000555556501893 R11: 0000000000000246 R12: 00007f18776e6cdc
R13: 00007fff7ba1cdf0 R14: 0000555556501810 R15: 00007fff7ba1ce30
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/13:
 #0: ffffffff8cf276f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518
1 lock held by rcu_tasks_trace/14:
 #0: ffffffff8cf27ab0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518
1 lock held by khungtaskd/28:
 #0: ffffffff8cf27520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by syslogd/4428:
 #0: ffff8880b983c1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
 #1: ffff8880b98287c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: rcu_lock_acquire+0x5/0x40 include/linux/rcupdate.h:326
 #2: ffff88802133d1c0 (&info->lock){....}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline]
 #2: ffff88802133d1c0 (&info->lock){....}-{2:2}, at: shmem_get_folio_gfp+0x1535/0x3470 mm/shmem.c:1985
2 locks held by getty/4742:
 #0: ffff888028bf5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176
1 lock held by syz-executor.5/5019:
 #0: ffff8880305de0e0 (&type->s_umount_key#92){++++}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:361
5 locks held by syz-executor.2/30746:
1 lock held by syz-executor.2/30815:
 #0: ffff8880305de0e0 (&type->s_umount_key#92){++++}-{3:3}, at: iterate_supers+0xb0/0x1e0 fs/super.c:743

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc4-syzkaller-00047-gafead42fdfca #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x187/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xec2/0xf00 kernel/hung_task.c:379
 kthread+0x2b8/0x350 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4435 Comm: klogd Not tainted 6.4.0-rc4-syzkaller-00047-gafead42fdfca #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5447 [inline]
RIP: 0010:lock_is_held_type+0xd6/0x190 kernel/locking/lockdep.c:5776
Code: 48 ff c3 49 63 85 c0 0a 00 00 48 83 c5 28 48 39 c3 7c d8 eb 11 48 c7 c7 c0 52 df 8c 48 89 de e8 20 aa bd f9 eb cb 31 ed eb 1f <41> 83 fe ff 74 14 31 c0 f6 45 22 03 0f 95 c0 31 ed 44 39 f0 40 0f
RSP: 0018:ffffc900000078e8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: 0000000000000009 RSI: ffff8880b983c1d8 RDI: ffff88807e2728d8
RBP: ffff88807e2728d8 R08: dffffc0000000000 R09: fffffbfff1cab90e
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000046
R13: ffff88807e271dc0 R14: 00000000ffffffff R15: ffff8880b983c1d8
FS:  00007fb77276d380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00083221c CR3: 0000000029f45000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 lock_is_held include/linux/lockdep.h:288 [inline]
 lockdep_assert_rq_held kernel/sched/sched.h:1357 [inline]
 rq_clock_task kernel/sched/sched.h:1509 [inline]
 update_curr+0x10c/0xa60 kernel/sched/fair.c:900
 enqueue_entity+0xb3/0x1790 kernel/sched/fair.c:4836
 enqueue_task_fair+0x23f/0xba0 kernel/sched/fair.c:6318
 enqueue_task+0x19d/0x2e0 kernel/sched/core.c:2082
 activate_task kernel/sched/core.c:2112 [inline]
 ttwu_do_activate+0x1d7/0x7b0 kernel/sched/core.c:3735
 ttwu_queue kernel/sched/core.c:3985 [inline]
 try_to_wake_up+0x734/0x1230 kernel/sched/core.c:4307
 autoremove_wake_function+0x16/0x110 kernel/sched/wait.c:419
 __wake_up_common+0x2a0/0x4e0 kernel/sched/wait.c:107
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up+0x11e/0x1d0 kernel/sched/wait.c:160
 irq_work_single+0xd9/0x230 kernel/irq_work.c:221
 irq_work_run_list kernel/irq_work.c:252 [inline]
 irq_work_run+0x18b/0x350 kernel/irq_work.c:261
 __sysvec_irq_work+0xa0/0x260 arch/x86/kernel/irq_work.c:22
 sysvec_irq_work+0x8d/0xb0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:671
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline]
RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline]
RIP: 0010:native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:205
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 f3 0f 1e fa 89 f6 31 d2 e9 27 ee 31 03 0f 1f 80 00 00 00
RSP: 0018:ffffc90005faf448 EFLAGS: 00000246
RAX: 00000000000000f6 RBX: ffffffff8ca43ae8 RCX: 000000000000083f
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f
RBP: 0000000000000000 R08: ffffffff8432aaaa R09: fffff52000bf5e75
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8d01b068
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000020
 arch_irq_work_raise+0x86/0xd0 arch/x86/kernel/irq_work.c:31
 irq_work_queue+0xa7/0x150 kernel/irq_work.c:124
 __kfence_alloc+0x22a/0x370 mm/kfence/core.c:1042
 kfence_alloc include/linux/kfence.h:128 [inline]
 slab_alloc_node mm/slub.c:3437 [inline]
 kmem_cache_alloc_node+0x2c6/0x350 mm/slub.c:3496
 __alloc_skb+0x181/0x420 net/core/skbuff.c:644
 alloc_skb include/linux/skbuff.h:1288 [inline]
 alloc_skb_with_frags+0xa8/0x750 net/core/skbuff.c:6380
 sock_alloc_send_pskb+0x919/0xa50 net/core/sock.c:2729
 unix_dgram_sendmsg+0x5b5/0x2050 net/unix/af_unix.c:1944
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 __sys_sendto+0x475/0x630 net/socket.c:2144
 __do_sys_sendto net/socket.c:2156 [inline]
 __se_sys_sendto net/socket.c:2152 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2152
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb7728cf9b5
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:00007ffda62e5a38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fb7728cf9b5
RDX: 0000000000000049 RSI: 000056482563f190 RDI: 0000000000000003
RBP: 0000564825636910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007fb772a5d212 R14: 00007ffda62e5b38 R15: 0000000000000000
 </TASK>