INFO: task kworker/u8:4:63 blocked for more than 143 seconds.
Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4 state:D stack:23488 pid:63 tgid:63 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-bcachefs-6)
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746
bch2_vfs_write_inode+0x6a/0xd0 fs/bcachefs/fs.c:2171
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.0.26:6103 blocked for more than 144 seconds.
Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.26 state:D stack:20664 pid:6103 tgid:6102 ppid:5819 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
__closure_sync+0x163/0x220 lib/closure.c:146
bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:256 [inline]
bch2_btree_update_start+0x1193/0x14c0 fs/bcachefs/btree_update_interior.c:1251
bch2_btree_split_leaf+0x13c/0x8f0 fs/bcachefs/btree_update_interior.c:1864
bch2_trans_commit_error+0x1a8/0x1100 fs/bcachefs/btree_trans_commit.c:904
__bch2_trans_commit+0x779c/0x8ae0 fs/bcachefs/btree_trans_commit.c:1069
bch2_trans_commit fs/bcachefs/btree_update.h:195 [inline]
__bch2_create+0x887/0xb90 fs/bcachefs/fs.c:593
bch2_mknod fs/bcachefs/fs.c:750 [inline]
bch2_mkdir+0x62/0xd0 fs/bcachefs/fs.c:910
vfs_mkdir+0x303/0x510 fs/namei.c:4359
do_mkdirat+0x247/0x590 fs/namei.c:4392
__do_sys_mkdir fs/namei.c:4414 [inline]
__se_sys_mkdir fs/namei.c:4412 [inline]
__x64_sys_mkdir+0x6c/0x80 fs/namei.c:4412
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5de1d8e969
RSP: 002b:00007f5de2bfc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f5de1fb5fa0 RCX: 00007f5de1d8e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000300
RBP: 00007f5de1e10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5de1fb5fa0 R15: 00007ffc5a144288
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
3 locks held by kworker/0:1/10:
#0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
#2: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#2: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
#2: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
4 locks held by kworker/u8:4/63:
#0: ffff888020a82148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff888020a82148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90001557c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90001557c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffff8880664320e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
#3: ffff888059290530 (&inode->ei_update_lock){+.+.}-{4:4}, at: bch2_vfs_write_inode+0x6a/0xd0 fs/bcachefs/fs.c:2171
2 locks held by kworker/u8:9/3036:
1 lock held by udevd/5192:
2 locks held by getty/5577:
#0: ffff888033bc00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900030062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by udevd/5974:
5 locks held by syz.0.26/6103:
#0: ffff888066432420 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff888059290148 (&sb->s_type->i_mutex_key#20/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline]
#1: ffff888059290148 (&sb->s_type->i_mutex_key#20/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4132
#2: ffff888059290530 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:567
#3: ffff888058a84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#3: ffff888058a84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#3: ffff888058a84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3385
#4: ffff888058aa6590 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179
2 locks held by bch-copygc/loop/6122:
2 locks held by syz.8.124/7248:
#0: ffff8880664320e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880664320e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff8880664347d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880664347d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.3.176/7868:
#0: ffff8880664320e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880664320e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff8880664347d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880664347d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz-executor/8060:
#0: ffff888079d4e0e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff888079d4e0e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff888079d4e0e0 (&type->s_umount_key#68){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
#1: ffffffff8df41200 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774
3 locks held by dhcpcd-run-hook/8615:
#0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
#2: ffff888031a86558 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffff888031a86558 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: handle_pte_fault mm/memory.c:6005 [inline]
#2: ffff888031a86558 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __handle_mm_fault+0xf74/0x5380 mm/memory.c:6140
3 locks held by dhcpcd-run-hook/8620:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 8619 Comm: dhcpcd-run-hook Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1089 [inline]
RIP: 0010:debug_check_no_obj_freed+0x205/0x470 lib/debugobjects.c:1129
Code: 00 ff c3 48 8b 44 24 18 49 89 c7 48 85 c0 0f 84 45 02 00 00 4d 89 fe 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df 41 80 3c 06 00 <74> 08 4c 89 ff e8 71 43 68 fd 49 8b 07 48 89 44 24 18 4d 8d 67 18
RSP: 0018:ffffc9000ad2f4c0 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000000002 RCX: dffffc0000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9000ad2f3a0
RBP: ffff888029611890 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520015a5e74 R12: ffff8880122c0018
R13: ffff888055025000 R14: 1ffff1100f1ef223 R15: ffff888078f79118
FS: 0000000000000000(0000) GS:ffff888126203000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffcc5c8458 CR3: 000000000dd36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
free_pages_prepare mm/page_alloc.c:1269 [inline]
free_unref_folios+0x429/0x1490 mm/page_alloc.c:2782
folios_put_refs+0x559/0x640 mm/swap.c:992
free_pages_and_swap_cache+0x4be/0x520 mm/swap_state.c:270
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:496
exit_mmap+0x474/0xba0 mm/mmap.c:1297
__mmput+0x118/0x410 kernel/fork.c:1379
exit_mm+0x1da/0x2c0 kernel/exit.c:589
do_exit+0x859/0x2550 kernel/exit.c:940
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c51809a90
Code: Unable to access opcode bytes at 0x7f4c51809a66.
RSP: 002b:00007fffcc5c8368 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055a14e1a5e04 RCX: 00007f4c51809a90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 0000000000000003 R08: 00007fffcc5c8460 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fffcc5c8688
R13: 00007fffcc5c86a0 R14: 000055a12aab1169 R15: 00007f4c51a08a80