syzbot

INFO: task syz-executor170:4995 blocked for more than 143 seconds.
      Not tainted 6.4.0-rc2-syzkaller-00015-g1b66c114d161 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor170 state:D stack:26216 pid:4995  ppid:4994   flags:0x00004006
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_timeout+0xb0/0x310 kernel/time/timer.c:2143
 do_wait_for_common+0x449/0x5f0 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x4a/0x60 kernel/sched/completion.c:138
 __flush_workqueue+0x743/0x1620 kernel/workqueue.c:2977
 nbd_start_device_ioctl drivers/block/nbd.c:1426 [inline]
 __nbd_ioctl drivers/block/nbd.c:1488 [inline]
 nbd_ioctl+0xb48/0xed0 drivers/block/nbd.c:1528
 blkdev_ioctl+0x602/0x7a0 block/ioctl.c:615
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 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: 0033:0x7f2e5095d379
RSP: 002b:00007fff3c9d7738 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2e5095d379
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007fff3c9d78d8 R09: 00007fff3c9d78d8
R10: 00007fff3c9d78d8 R11: 0000000000000246 R12: 00007f2e5091c690
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/13:
 #0: ffffffff8cf27670 (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: ffffffff8cf27a30 (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: ffffffff8cf274a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u5:1/4398:
 #0: ffff88801ff6b138 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378
 #1: ffffc90006d17d20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380
2 locks held by getty/4748:
 #0: ffff88802d542098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc2-syzkaller-00015-g1b66c114d161 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
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: 1008 Comm: kworker/u4:5 Not tainted 6.4.0-rc2-syzkaller-00015-g1b66c114d161 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:kasan_check_range+0x9/0x290 mm/kasan/generic.c:186
Code: c7 e8 6b 7d cc 08 31 c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 0f 1f 84 00 00 00 00 00 66 0f 1f 00 55 41 57 41 56 <53> b0 01 48 85 f6 0f 84 9a 01 00 00 48 89 fd 48 01 f5 0f 82 5a 02
RSP: 0018:ffffc90005a5f558 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000032 RCX: ffffffff816b1c9a
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90328260
RBP: 0000000000000019 R08: ffff888021310ac8 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000040032
R13: 1ffff11004262155 R14: 0000000000000000 R15: 0000000000000032
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559686d15680 CR3: 000000000cd30000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 hlock_class kernel/locking/lockdep.c:228 [inline]
 check_wait_context kernel/locking/lockdep.c:4746 [inline]
 __lock_acquire+0x4aa/0x2000 kernel/locking/lockdep.c:5024
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:350 [inline]
 __get_locked_pte+0x16d/0x1c0 mm/memory.c:1810
 get_locked_pte include/linux/mm.h:2583 [inline]
 __text_poke+0x284/0x9b0 arch/x86/kernel/alternative.c:1584
 text_poke arch/x86/kernel/alternative.c:1669 [inline]
 text_poke_bp_batch+0x485/0x950 arch/x86/kernel/alternative.c:1992
 text_poke_flush arch/x86/kernel/alternative.c:2161 [inline]
 text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2168
 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146
 static_key_disable_cpuslocked+0xce/0x1b0 kernel/jump_label.c:235
 static_key_disable+0x1a/0x20 kernel/jump_label.c:243
 toggle_allocation_gate+0x1b8/0x250 mm/kfence/core.c:836
 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405
 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552
 kthread+0x2b8/0x350 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.202 msecs