syzbot


INFO: task hung in __block_write_full_folio

Status: auto-obsoleted due to no activity on 2025/08/01 00:24
Subsystems: hfs
[Documentation on labels]
First crash: 117d, last: 117d

Sample crash report:
INFO: task syz.2.151:7160 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.151       state:D stack:24680 pid:7160  tgid:7158  ppid:5816   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 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
 io_schedule+0x81/0xe0 kernel/sched/core.c:7742
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:247
 __wait_on_bit_lock+0xe9/0x4f0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x123/0x170 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline]
 __lock_buffer fs/buffer.c:71 [inline]
 lock_buffer include/linux/buffer_head.h:434 [inline]
 __block_write_full_folio+0x54f/0xe10 fs/buffer.c:1916
 write_cache_pages+0x61/0x100 mm/page-writeback.c:2613
 blkdev_writepages+0xa8/0x100 block/fops.c:458
 do_writepages+0x3ae/0x7b0 mm/page-writeback.c:2656
 filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 filemap_write_and_wait_range+0x217/0x310 mm/filemap.c:691
 hfs_file_fsync+0x113/0x140 fs/hfs/inode.c:682
 generic_write_sync include/linux/fs.h:2976 [inline]
 generic_file_write_iter+0x311/0x540 mm/filemap.c:4250
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x548/0xa90 fs/read_write.c:684
 ksys_write+0x145/0x250 fs/read_write.c:736
 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: 0033:0x7fef3b78e969
RSP: 002b:00007fef3c6e2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fef3b9b5fa0 RCX: 00007fef3b78e969
RDX: 0000000000004000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007fef3b810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fef3b9b5fa0 R15: 00007ffca35fc7d8
 </TASK>
INFO: task syz.2.151:7163 blocked for more than 144 seconds.
      Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.151       state:D stack:26968 pid:7163  tgid:7158  ppid:5816   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 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
 io_schedule+0x81/0xe0 kernel/sched/core.c:7742
 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
 folio_lock include/linux/pagemap.h:1137 [inline]
 __find_get_block_slow fs/buffer.c:205 [inline]
 find_get_block_common+0x2e6/0xfc0 fs/buffer.c:1413
 bdev_getblk+0x4b/0x670 fs/buffer.c:-1
 __bread_gfp+0x89/0x3c0 fs/buffer.c:1520
 sb_bread include/linux/buffer_head.h:348 [inline]
 hfs_mdb_commit+0xa42/0x1160 fs/hfs/mdb.c:318
 hfs_sync_fs+0x15/0x20 fs/hfs/super.c:37
 sync_filesystem+0xeb/0x230 fs/sync.c:56
 hfs_reconfigure+0x66/0x270 fs/hfs/super.c:119
 reconfigure_super+0x224/0x890 fs/super.c:1083
 do_remount fs/namespace.c:3368 [inline]
 path_mount+0xd18/0xfe0 fs/namespace.c:4203
 do_mount fs/namespace.c:4224 [inline]
 __do_sys_mount fs/namespace.c:4435 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.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: 0033:0x7fef3b79010a
RSP: 002b:00007fef3c6c0e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fef3c6c0ef0 RCX: 00007fef3b79010a
RDX: 0000200000000180 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 0000200000000180 R08: 00007fef3c6c0ef0 R09: 0000000002046022
R10: 0000000002046022 R11: 0000000000000246 R12: 0000200000000000
R13: 00007fef3c6c0eb0 R14: 0000000000000000 R15: 00002000000002c0
 </TASK>

Showing all locks held in the system:
2 locks held by ksoftirqd/0/15:
 #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
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
3 locks held by kworker/u8:3/54:
 #0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
 #1: ffffc90000bf7c60 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000bf7c60 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffff8880b8825558 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1046 [inline]
 #2: ffff8880b8825558 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1127
3 locks held by kworker/u8:7/3481:
 #0: ffff88801eae2948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801eae2948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc9000c057c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000c057c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffff88801b2960e0 (&type->s_umount_key#41){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
2 locks held by getty/5583:
 #0: ffff8880275070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by udevd/5868:
 #0: ffff88802288e3a0 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline]
 #0: ffff88802288e3a0 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:808
 #1: ffff88802288e540 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline]
 #1: ffff88802288e540 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2451 [inline]
 #1: ffff88802288e540 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x7db/0x1eb0 mm/filemap.c:2613
2 locks held by kworker/1:3/5874:
 #0: ffff88801a081548 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a081548 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc9000410fc60 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000410fc60 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
3 locks held by syz.2.151/7160:
 #0: ffff888032db80f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213
 #1: ffff88807b976420 (sb_writers#27){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
 #1: ffff88807b976420 (sb_writers#27){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680
 #2: ffff88802408a320 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #2: ffff88802408a320 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: hfs_file_fsync+0x9a/0x140 fs/hfs/inode.c:673
1 lock held by syz.2.151/7163:
 #0: ffff88807b9760e0 (&type->s_umount_key#103){++++}-{4:4}, at: do_remount fs/namespace.c:3365 [inline]
 #0: ffff88807b9760e0 (&type->s_umount_key#103){++++}-{4:4}, at: path_mount+0xcd2/0xfe0 fs/namespace.c:4203
1 lock held by syz.6.567/9275:
 #0: ffff88807b9760e0 (&type->s_umount_key#103){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88807b9760e0 (&type->s_umount_key#103){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
2 locks held by syz.3.582/9344:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9344 Comm: syz.3.582 Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:-1 [inline]
RIP: 0010:rcu_is_watching+0x44/0xb0 kernel/rcu/tree.c:736
Code: 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10 8c 95 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 ac a7 78 00 <48> c7 c3 58 2b 73 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38
RSP: 0018:ffffc9000b7c72d8 EFLAGS: 00000246
RAX: 1ffffffff1b2b183 RBX: 0000000000000001 RCX: acf54dee3ea68300
RDX: 0000000000000000 RSI: ffffffff8bc0fd40 RDI: ffffffff8bc0fd00
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff817199f5 R12: 1ffff920016f8e79
R13: ffffc9000b7c7400 R14: ffffffff8d958c18 R15: dffffc0000000000
FS:  00007f54758276c0(0000) GS:ffff888126200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa0b4f80178 CR3: 0000000056b34000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rcu_read_lock include/linux/rcupdate.h:842 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xd4/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf7/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 free_unref_folios+0xb70/0x1490 mm/page_alloc.c:2782
 folios_put_refs+0x559/0x640 mm/swap.c:992
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1125
 shmem_fallocate+0xc70/0xde0 mm/shmem.c:3753
 vfs_fallocate+0x6a0/0x830 fs/open.c:338
 ksys_fallocate fs/open.c:362 [inline]
 __do_sys_fallocate fs/open.c:367 [inline]
 __se_sys_fallocate fs/open.c:365 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:365
 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: 0033:0x7f547498e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5475827038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f5474bb5fa0 RCX: 00007f547498e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f5474a10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008000c62 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5474bb5fa0 R15: 00007ffc5d6c3748
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/03 00:22 upstream 2bfcee565c3a b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in __block_write_full_folio
* Struck through repros no longer work on HEAD.