INFO: task syz-executor:5845 blocked for more than 143 seconds.
Not tainted 6.16.0-rc3-next-20250626-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:19048 pid:5845 tgid:5845 ppid:1 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5313 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
__schedule_loop kernel/sched/core.c:6774 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6789
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
kthread_stop+0x194/0x5f0 kernel/kthread.c:790
bch2_copygc_stop+0x4f/0x150 fs/bcachefs/movinggc.c:438
__bch2_fs_read_only+0x47/0x5b0 fs/bcachefs/super.c:280
bch2_fs_read_only+0x42a/0xb00 fs/bcachefs/super.c:366
__bch2_fs_stop+0x100/0x900 fs/bcachefs/super.c:677
generic_shutdown_super+0x132/0x2c0 fs/super.c:643
bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2619
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d0c18fc57
RSP: 002b:00007ffd574d3468 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f0d0c210925 RCX: 00007f0d0c18fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd574d3520
RBP: 00007ffd574d3520 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd574d45b0
R13: 00007f0d0c210925 R14: 000000000005df0c R15: 00007ffd574d45f0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13bf20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13bf20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13bf20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5598:
#0: ffff88814dc570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/5845:
#0: ffff8880402020e0 (&type->s_umount_key#64){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880402020e0 (&type->s_umount_key#64){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880402020e0 (&type->s_umount_key#64){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff888045380278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:676
2 locks held by bch-copygc/loop/11253:
#0: ffff888045384398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#0: ffff888045384398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#0: ffff888045384398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3300
#1: ffff8880453a6710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1202
3 locks held by syz.2.3479/14226:
3 locks held by syz.0.3482/14233:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-next-20250626-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14233 Comm: syz.0.3482 Not tainted 6.16.0-rc3-next-20250626-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4857 [inline]
RIP: 0010:__lock_acquire+0x332/0xd20 kernel/locking/lockdep.c:5190
Code: e5 15 09 d5 09 cd 44 09 f5 41 89 6c c7 20 45 89 44 c7 24 4c 89 7c 24 10 4d 8d 34 c7 81 e5 ff 1f 00 00 48 0f a3 2d 3e 22 0a 12 <73> 10 48 69 c5 c8 00 00 00 48 8d 80 30 c3 48 93 eb 40 83 3d 85 b1
RSP: 0018:ffffc9001cabf548 EFLAGS: 00000003
RAX: 000000000000000a RBX: ffffffff8e2445e0 RCX: 00000000000000a7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888025953c00
RBP: 00000000000000a7 R08: 0000000000000000 R09: ffffffff82166103
R10: ffffc9001cabf740 R11: fffff52003957eed R12: 0000000000000000
R13: 0000000000000000 R14: ffff888025954740 R15: ffff8880259546f0
FS: 00007f713ebb36c0(0000) GS:ffff888125d1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f27fca02000 CR3: 0000000028dba000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
__fs_reclaim_acquire mm/page_alloc.c:4231 [inline]
fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4245
might_alloc include/linux/sched/mm.h:318 [inline]
prepare_alloc_pages+0x153/0x610 mm/page_alloc.c:4913
__alloc_frozen_pages_noprof+0x123/0x370 mm/page_alloc.c:5134
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2438
shmem_alloc_folio mm/shmem.c:1871 [inline]
shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1910
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2537
shmem_get_folio mm/shmem.c:2643 [inline]
shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3293
generic_perform_write+0x2c4/0x910 mm/filemap.c:4175
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3468
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x54b/0xa90 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f713dd8d3df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f713ebb2df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000002000000 RCX: 00007f713dd8d3df
RDX: 0000000002000000 RSI: 00007f7133600000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000080ef
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f713ebb2ef0 R14: 00007f713ebb2eb0 R15: 00007f7133600000