syzbot

INFO: task syz-executor342:4162 blocked for more than 143 seconds.
      Not tainted 5.15.179-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor342 state:D
 stack:24864 pid: 4162 ppid:  4160 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 schedule+0x11b/0x1f0 kernel/sched/core.c:6458
 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191
 sync_inodes_sb+0x293/0xab0 fs/fs-writeback.c:2770
 sync_filesystem+0x16b/0x220 fs/sync.c:64
 generic_shutdown_super+0x6b/0x310 fs/super.c:448
 kill_block_super+0x7a/0xe0 fs/super.c:1427
 deactivate_locked_super+0xa0/0x110 fs/super.c:335
 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc72af4f407
RSP: 002b:00007ffc6c058638 EFLAGS: 00000202
 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fc72af4f407
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc6c0586f0
RBP: 00007ffc6c0586f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffc6c059760
R13: 00005555625f86c0 R14: 0000000000000001 R15: 431bde82d7b634db
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/1:1/23:
1 lock held by khungtaskd/27:
 #0: 
ffffffff8cb1f4e0
 (
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:1/144:
 #0: 
ffff888019b98938
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: 
ffffc900016dfd20
 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: 
ffff88802ae0c650
 (
sb_internal
#2
){.+.+}-{0:0}
, at: xfs_bmapi_convert_delalloc+0x20f/0x1180 fs/xfs/libxfs/xfs_bmap.c:4573
 #3: 
ffff888072309768
 (
&xfs_nondir_ilock_class
){++++}-{3:3}
, at: xfs_bmapi_convert_delalloc+0x23c/0x1180 fs/xfs/libxfs/xfs_bmap.c:4578
2 locks held by getty/3926:
 #0: 
ffff88802ae91098
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: 
ffffc900026362e8
 (
&ldata->atomic_read_lock
){+.+.}-{3:3}
, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by syz-executor342/4162:
 #0: 
ffff88802ae0c0e0
 (
&type->s_umount_key
#43
){+.+.}-{3:3}
, at: deactivate_super+0xa9/0xe0 fs/super.c:365
 #1: 
ffff888020ac07d8
 (
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:369
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: xfs-buf/loop0 xfs_buf_ioend_work
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x81/0x290 mm/kasan/generic.c:189
Code: df 4f 8d 34 1a 4c 89 f5 4c 29 cd 48 83 fd 10 7f 26 48 85 ed 0f 84 3a 01 00 00 49 f7 d2 49 01 da 41 80 39 00 0f 85 c4 01 00 00 <49> ff c1 49 ff c2 75 ee e9 1d 01 00 00 45 89 cf 41 83 e7 07 0f 84
RSP: 0018:ffffc90000dd0638 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff920001ba148 RCX: ffffffff815d49fa
RDX: 0000000000000001 RSI: 0000000000000050 RDI: ffffc90000dd0a40
RBP: 000000000000000a R08: dffffc0000000000 R09: fffff520001ba151
R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000000000001
R13: 0000000000000010 R14: fffff520001ba152 R15: ffff88813fe47210
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fe07429600 CR3: 000000002baf8000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 memset+0x1f/0x40 mm/kasan/shadow.c:44
 update_sd_lb_stats kernel/sched/fair.c:9554 [inline]
 find_busiest_group kernel/sched/fair.c:9831 [inline]
 load_balance+0xada/0x76e0 kernel/sched/fair.c:10213
 rebalance_domains+0x546/0xa80 kernel/sched/fair.c:10632
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:console_trylock_spinning+0x36b/0x3f0 kernel/printk/printk.c:1909
Code: 0f 84 75 ff ff ff e8 14 1a 1a 00 fb 31 db eb 48 e8 0a 1a 1a 00 e8 95 7c d9 08 4d 85 ed 74 cd e8 fb 19 1a 00 fb bb 01 00 00 00 <48> c7 c7 a0 bd 9f 8c 31 f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00
RSP: 0018:ffffc90000ddf7c0 EFLAGS: 00000293
RAX: ffffffff816682c5 RBX: 0000000000000001 RCX: ffff88813fe58000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000ddf890 R08: ffffffff8166827e R09: fffffbfff2131e33
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001bbef8
R13: 0000000000000200 R14: 0000000000000046 R15: dffffc0000000000
 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273
 _printk+0xd1/0x120 kernel/printk/printk.c:2299
 __xfs_printk fs/xfs/xfs_message.c:24 [inline]
 xfs_alert+0x1c8/0x320 fs/xfs/xfs_message.c:52
 xfs_buf_verifier_error+0x161/0x290 fs/xfs/xfs_error.c:412
 xfs_agf_read_verify+0x1f8/0x2a0 fs/xfs/libxfs/xfs_alloc.c:2955
 xfs_buf_ioend+0x26a/0x6e0 fs/xfs/xfs_buf.c:1263
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.761 msecs