INFO: task hung in jbd2_journal_commit_transaction (2)

Status: upstream: reported syz repro on 2025/07/11 16:44
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+9a89536a77a7521a4a2a@syzkaller.appspotmail.com
First crash: 390d, last: 6h29m
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/07/12 linux-6.1.y (ToT) dfc486ec9cce syz [report] INFO: rcu detected stall in corrupted
2025/07/12 upstream (ToT) 379f604cc3dc syz Didn't crash
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 INFO: task hung in jbd2_journal_commit_transaction 1 syz, C 5 20h58m 5d15h 0/1 premoderation: reported C repro on 2026/07/31 15:32
upstream INFO: task hung in jbd2_journal_commit_transaction (2) ext4 1 1 1973d 1973d 0/29 auto-closed as invalid on 2021/06/09 10:13
linux-6.6 INFO: task hung in jbd2_journal_commit_transaction (2) 1 1 8h45m 8h45m 0/2 upstream: reported on 2026/08/05 22:06
android-44 INFO: task hung in jbd2_journal_commit_transaction 1 syz, C 6 2959d 2672d 0/2 public: reported C repro on 2019/04/13 00:00
android-49 INFO: task hung in jbd2_journal_commit_transaction 1 5 2866d 3011d 0/3 auto-closed as invalid on 2019/03/29 12:13
upstream INFO: task hung in jbd2_journal_commit_transaction (5) ext4 1 syz, C error error 2238 now 813d 0/29 upstream: reported C repro on 2024/05/15 03:54
linux-6.1 INFO: task hung in jbd2_journal_commit_transaction 1 1 1161d 1161d 0/3 auto-obsoleted due to no activity on 2023/09/09 09:50
linux-5.15 INFO: task hung in jbd2_journal_commit_transaction 1 2 9h40m 1d01h 0/3 upstream: reported on 2026/08/05 05:38
upstream INFO: task hung in jbd2_journal_commit_transaction (4) ext4 1 7 1105d 1253d 0/29 auto-obsoleted due to no activity on 2023/10/25 18:13
upstream INFO: task hung in jbd2_journal_commit_transaction (3) ext4 1 syz, C error error 24 1406d 1691d 0/29 auto-obsoleted due to no activity on 2023/01/27 09:20
upstream INFO: task hung in jbd2_journal_commit_transaction ext4 1 syz, C 52 2853d 2872d 0/29 closed as dup on 2018/10/02 14:53
linux-6.6 INFO: task hung in jbd2_journal_commit_transaction 1 2 304d 391d 0/2 auto-obsoleted due to no activity on 2026/01/13 11:32
android-414 INFO: task hung in jbd2_journal_commit_transaction 1 syz, C 31 2858d 2674d 0/1 public: reported C repro on 2019/04/11 00:00
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/08/05 01:44 3h04m fix candidate upstream OK (0) job log

Sample crash report:
INFO: task jbd2/sda1-8:3600 blocked for more than 143 seconds.
      Not tainted 6.1.144-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:jbd2/sda1-8     state:D stack:25792 pid:3600  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8797
 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0xa8/0x2d0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x11f/0x160 kernel/sched/wait_bit.c:64
 wait_on_buffer include/linux/buffer_head.h:385 [inline]
 journal_wait_on_commit_record fs/jbd2/commit.c:175 [inline]
 jbd2_journal_commit_transaction+0x3764/0x60e0 fs/jbd2/commit.c:922
 kjournald2+0x412/0x810 fs/jbd2/journal.c:210
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cb2b730 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8cb2bf50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
 #0: ffffffff8cb2ada0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2ada0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2ada0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4029:
 #0: ffff88807e208098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-execprog/4276:
1 lock held by syz.1.17/4467:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.144-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xeee/0xf30 kernel/hung_task.c:377
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4467 Comm: syz.1.17 Not tainted 6.1.144-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__preempt_count_sub arch/x86/include/asm/preempt.h:85 [inline]
RIP: 0010:preempt_count_sub+0x58/0x160 kernel/sched/core.c:5748
Code: 05 a5 c0 aa 7e 89 c1 81 e1 ff ff ff 7f 39 cf 7f 25 81 ff ff 00 00 00 0f 93 c1 84 c0 0f 95 c0 08 c8 74 53 65 8b 05 80 c0 aa 7e <f7> df 65 01 3d 77 c0 aa 7e 5b 5d c3 e8 97 06 ad 02 85 c0 74 f4 48
RSP: 0018:ffffc900001e0878 EFLAGS: 00000002
RAX: 0000000080010004 RBX: dffffc0000000000 RCX: 0000000000010000
RDX: ffffc900001e0901 RSI: dffffc0000000000 RDI: 0000000000000001
RBP: ffffffff8ea4b564 R08: ffffc90003367dc0 R09: ffffc900001e09b8
R10: fffff5200003c139 R11: 1ffff9200003c137 R12: ffffc90003360000
R13: dffffc0000000000 R14: ffffc900001e0978 R15: ffffc90003367dd0
FS:  000055556bf72500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007c63d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 unwind_next_frame+0x1880/0x20b0 arch/x86/kernel/unwind_orc.c:629
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3422
 __sigqueue_alloc+0x40c/0x520 kernel/signal.c:436
 __send_signal_locked+0x22f/0xde0 kernel/signal.c:1129
 do_send_sig_info kernel/signal.c:1301 [inline]
 group_send_sig_info+0x1f6/0x250 kernel/signal.c:1449
 do_bpf_send_signal+0x7b/0x150 kernel/trace/bpf_trace.c:840
 irq_work_single+0xd1/0x230 kernel/irq_work.c:211
 irq_work_run_list kernel/irq_work.c:242 [inline]
 irq_work_run+0x152/0x2e0 kernel/irq_work.c:251
 __sysvec_irq_work+0xba/0x350 arch/x86/kernel/irq_work.c:22
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x98/0xc0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline]
RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline]
RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:206
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 8f b1 f8 02 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90003367cb0 EFLAGS: 00000246
RAX: 00000000000000f6 RBX: ffffffff8c5e4b88 RCX: 000000000000083f
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff5200066cf85
R10: fffff5200066cf85 R11: 1ffff9200066cf84 R12: ffff8880b8f33e01
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000020
 arch_irq_work_raise+0x82/0xd0 arch/x86/kernel/irq_work.c:31
 irq_work_queue+0x95/0x140 kernel/irq_work.c:114
 bpf_send_signal_common+0x2b2/0x420 kernel/trace/bpf_trace.c:879
 ____bpf_send_signal kernel/trace/bpf_trace.c:888 [inline]
 bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:886
 bpf_prog_7ba5217f62dcd359+0x38/0x3c
 bpf_dispatcher_nop_func include/linux/bpf.h:1001 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline]
 bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324
 __bpf_trace_sys_enter+0x60/0x70 include/trace/events/syscalls.h:18
 trace_sys_enter+0x6b/0x80 include/trace/events/syscalls.h:18
 syscall_trace_enter+0xf0/0x150 kernel/entry/common.c:81
 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:77
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f609e12ab19
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007ffdb9de8c00 EFLAGS: 00000246 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f609e3b5fa8 RCX: 00007f609e12ab19
RDX: 00007ffdb9de8c00 RSI: 00007ffdb9de8d30 RDI: 0000000000000011
RBP: 0000000000000000 R08: 001de2c73f1b896c R09: 00000007b9de94af
R10: 0000000000000005 R11: 0000000000000246 R12: 00007f609e3b5fac
R13: 00007f609e3b5fa0 R14: 0000000000000095 R15: 0000000000000003
 </TASK>

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/11 16:43 linux-6.1.y dfc486ec9cce 3cda49cf .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2026/08/06 00:22 linux-6.1.y fb28aa725e05 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2026/08/06 00:21 linux-6.1.y fb28aa725e05 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2026/08/05 22:12 linux-6.1.y fb28aa725e05 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2026/08/05 05:55 linux-6.1.y fb28aa725e05 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2026/08/05 05:55 linux-6.1.y fb28aa725e05 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2026/08/05 05:55 linux-6.1.y fb28aa725e05 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2026/08/05 05:55 linux-6.1.y fb28aa725e05 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2026/08/05 01:43 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
2025/12/26 07:55 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in jbd2_journal_commit_transaction
* Struck through repros no longer work on HEAD.