syzbot


INFO: task hung in flush_old_commits

Status: upstream: reported C repro on 2023/04/04 05:08
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+1402b2dbcd2d308b6f11@syzkaller.appspotmail.com
First crash: 465d, last: 33d
Bug presence (1)
Date Name Commit Repro Result
2023/09/16 upstream (ToT) 57d88e8a5974 C [report] INFO: task hung in flush_old_commits
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in flush_old_commits origin:upstream C error 64 1d18h 479d 0/3 upstream: reported C repro on 2023/03/21 14:16
upstream INFO: task hung in flush_old_commits reiserfs C done done 113 165d 417d 0/27 auto-obsoleted due to no activity on 2024/04/23 04:32
Fix bisection attempts (7)
Created Duration User Patch Repo Result
2024/05/07 19:13 1h20m bisect fix linux-6.1.y OK (0) job log log
2024/04/03 13:12 1h50m bisect fix linux-6.1.y OK (0) job log log
2024/02/03 15:34 1h21m (2) bisect fix linux-6.1.y OK (0) job log log
2023/12/31 19:11 2h01m bisect fix linux-6.1.y OK (0) job log log
2023/12/01 14:25 1h50m bisect fix linux-6.1.y OK (0) job log log
2023/10/31 09:07 2h01m bisect fix linux-6.1.y OK (0) job log log
2023/09/01 04:02 2h17m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
INFO: task kworker/1:1:26 blocked for more than 143 seconds.
      Not tainted 6.1.80-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1     state:D stack:25464 pid:26    ppid:2      flags:0x00004000
Workqueue: events_long flush_old_commits
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 reiserfs_write_lock+0x76/0xd0 fs/reiserfs/lock.c:27
 reiserfs_sync_fs fs/reiserfs/super.c:76 [inline]
 flush_old_commits+0x1df/0x2e0 fs/reiserfs/super.c:111
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12aa90 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12b290 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
4 locks held by kworker/1:1/26:
 #0: ffff888012471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000a1fd20 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff88801eb220e0 (&type->s_umount_key#41){++++}-{3:3}
, at: flush_old_commits+0xc7/0x2e0 fs/reiserfs/super.c:97
 #3: ffff888019b20090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x76/0xd0 fs/reiserfs/lock.c:27
1 lock held by khungtaskd/28:
 #0: ffffffff8d12a8c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:319 [inline]
 #0: ffffffff8d12a8c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:760 [inline]
 #0: ffffffff8d12a8c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by getty/3301:
 #0: ffff88814b700098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
6 locks held by syz-executor230/3565:

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.80-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3565 Comm: syz-executor230 Not tainted 6.1.80-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:203
Code: e8 25 00 00 00 0f 0b 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 58 9f e8 0c 48 89 de 5b e9 b7 9e 56 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0d 24 f0 77 7e 65 8b 15 25 f0 77 7e f7 c2 00
RSP: 0018:ffffc900000e6458 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff8aecb0e1 RCX: ffff88807e6ebb80
RDX: ffff88807e6ebb80 RSI: 0000000000000025 RDI: 0000000000000000
RBP: ffffc900000e6550 R08: ffffffff8a83d7f5 R09: ffffffff8a83d4ac
R10: 0000000000000002 R11: ffff88807e6ebb80 R12: ffffffff8aecb0e0
R13: 1ffff9200001cc9c R14: ffffffff8aecb0e1 R15: 0000000000000025
FS:  00005555564d4380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc2a72d088 CR3: 0000000013ec4000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 format_decode+0x72f/0x1f10 lib/vsprintf.c:2545
 vsnprintf+0x14d/0x1c70 lib/vsprintf.c:2757
 sprintf+0xd6/0x120 lib/vsprintf.c:3009
 print_time kernel/printk/printk.c:1274 [inline]
 info_print_prefix+0x167/0x300 kernel/printk/printk.c:1300
 record_print_text kernel/printk/printk.c:1349 [inline]
 console_emit_next_record+0x71c/0xea0 kernel/printk/printk.c:2725
 console_unlock+0x278/0x7c0 kernel/printk/printk.c:2871
 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2268
 _printk+0xd1/0x111 kernel/printk/printk.c:2293
 __reiserfs_warning+0x14f/0x1a0 fs/reiserfs/prints.c:290
 reiserfs_read_bitmap_block+0x232/0x6c0 fs/reiserfs/bitmap.c:1434
 scan_bitmap_block+0x19d/0xfe0 fs/reiserfs/bitmap.c:164
 scan_bitmap fs/reiserfs/bitmap.c:402 [inline]
 allocate_without_wrapping_disk fs/reiserfs/bitmap.c:1161 [inline]
 blocknrs_and_prealloc_arrays_from_search_start fs/reiserfs/bitmap.c:1274 [inline]
 reiserfs_allocate_blocknrs+0x2cf5/0x5070 fs/reiserfs/bitmap.c:1375
 reiserfs_get_block+0x3296/0x5150 fs/reiserfs/inode.c:756
 __block_write_begin_int+0x544/0x1a30 fs/buffer.c:1991
 reiserfs_write_begin+0x249/0x510 fs/reiserfs/inode.c:2775
 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3817
 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3945
 generic_file_write_iter+0xab/0x310 mm/filemap.c:3977
 call_write_iter include/linux/fs.h:2251 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x7ae/0xba0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4d9970af99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc65e2b0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4d99754095 RCX: 00007f4d9970af99
RDX: 00000000000000c1 RSI: 00000000200002c0 RDI: 0000000000000005
RBP: 00007f4d997805f0 R08: 0000000020000000 R09: 00005555564d54c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc65e2b0f0
R13: 00007ffc65e2b318 R14: 431bde82d7b634db R15: 00007f4d9975401d
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.357 msecs

Crashes (22):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/03 20:44 linux-6.1.y a3eb3a74aa8c 25905f5d .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan INFO: task hung in flush_old_commits
2023/09/16 13:26 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan INFO: task hung in flush_old_commits
2023/05/19 06:31 linux-6.1.y fa74641fb6b9 3bb7af1d .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/06/24 08:39 linux-6.1.y e84a4e368abe 79782afc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan INFO: task hung in flush_old_commits
2023/06/22 01:32 linux-6.1.y e84a4e368abe 79782afc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2024/06/06 00:36 linux-6.1.y 88690811da69 5aa1a7c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in flush_old_commits
2024/06/05 23:56 linux-6.1.y 88690811da69 5aa1a7c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in flush_old_commits
2024/06/05 23:16 linux-6.1.y 88690811da69 5aa1a7c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in flush_old_commits
2024/05/23 12:07 linux-6.1.y 4078fa637fcd 4c2072ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in flush_old_commits
2023/09/27 06:21 linux-6.1.y d23900f974e0 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in flush_old_commits
2024/06/09 22:51 linux-6.1.y 88690811da69 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2024/06/09 22:40 linux-6.1.y 88690811da69 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/09/30 11:12 linux-6.1.y d23900f974e0 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/06/08 23:01 linux-6.1.y 76ba310227d2 058b3a5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/06/08 21:24 linux-6.1.y 76ba310227d2 058b3a5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/06/04 23:35 linux-6.1.y d2869ace6eeb a4ae4f42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/05/22 14:04 linux-6.1.y fa74641fb6b9 4bce1a3e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/04/22 17:33 linux-6.1.y f17b0ab65d17 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/04/22 06:09 linux-6.1.y f17b0ab65d17 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/04/19 02:26 linux-6.1.y 0102425ac76b d931e9f0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/04/05 05:19 linux-6.1.y 3b29299e5f60 831373d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
2023/04/04 05:08 linux-6.1.y 3b29299e5f60 41147e3e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in flush_old_commits
* Struck through repros no longer work on HEAD.