syzbot


WARNING in __jbd2_log_wait_for_space

Status: upstream: reported C repro on 2025/01/03 03:46
Subsystems: ocfs2 ext4
[Documentation on labels]
Reported-by: syzbot+04ae2c9e709a347f1a81@syzkaller.appspotmail.com
First crash: 359d, last: 34d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: WARNING in __jbd2_log_wait_for_space (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit 93ce0ff117b0c468961d7c296a03ad57e1e8da9f
Author: Deepanshu Kartikey <kartikey406@gmail.com>
Date: Thu Oct 30 15:30:03 2025 +0000

  ocfs2: validate cl_bpc in allocator inodes to prevent divide-by-zero

  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ext4?] [ocfs2?] WARNING in __jbd2_log_wait_for_space 0 (2) 2025/12/24 00:32
Last patch testing requests (10)
Created Duration User Patch Repo Result
2025/12/09 11:04 23m retest repro upstream OK log
2025/11/19 21:17 21m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/11/19 21:17 30m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/11/05 07:43 24m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/10/21 23:34 14m retest repro upstream report log
2025/09/28 21:34 13m retest repro upstream report log
2025/08/27 06:45 19m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/08/27 06:45 19m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/08/27 06:45 23m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/08/12 22:40 14m retest repro upstream report log
Fix bisection attempts (5)
Created Duration User Patch Repo Result
2025/12/23 18:00 6h30m bisect fix upstream OK (1) job log
2025/07/20 02:28 1h42m bisect fix upstream OK (0) job log log
2025/06/02 18:35 2h15m bisect fix upstream OK (0) job log log
2025/05/01 12:38 4h08m bisect fix upstream OK (0) job log log
2025/03/05 12:24 1h46m bisect fix upstream OK (0) job log log

Sample crash report:
__jbd2_log_wait_for_space: needed 5461 blocks and only had 1246 space available
__jbd2_log_wait_for_space: no way to get more journal space in loop0-75
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5423 at fs/jbd2/checkpoint.c:115 __jbd2_log_wait_for_space+0x3b5/0x480 fs/jbd2/checkpoint.c:115
Modules linked in:
CPU: 0 UID: 0 PID: 5423 Comm: syz-executor Not tainted 6.16.0-syzkaller-02094-g86aa72182095 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__jbd2_log_wait_for_space+0x3b5/0x480 fs/jbd2/checkpoint.c:115
Code: 3f 96 9c 8d 48 8b 54 24 28 44 89 f1 e8 94 b1 9f fe 48 c7 c7 20 11 a0 8b 48 c7 c6 3f 96 9c 8d 48 8b 54 24 40 e8 7c b1 9f fe 90 <0f> 0b 90 4c 8b 24 24 4c 89 e7 be fb ff ff ff e8 b7 34 01 00 e9 38
RSP: 0018:ffffc9000cb97588 EFLAGS: 00010246
RAX: 0000000000000047 RBX: 0000000000000000 RCX: 7a5dbe71832d2900
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffff88801fc24293 R09: 1ffff11003f84852
R10: dffffc0000000000 R11: ffffed1003f84853 R12: 0000000000000000
R13: ffff88805960e190 R14: 00000000000004de R15: dffffc0000000000
FS:  000055555da55500(0000) GS:ffff88808d27c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00857c000 CR3: 000000004d82f000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 add_transaction_credits fs/jbd2/transaction.c:279 [inline]
 start_this_handle+0x122f/0x21c0 fs/jbd2/transaction.c:403
 jbd2__journal_start+0x2c1/0x5b0 fs/jbd2/transaction.c:501
 jbd2_journal_start+0x2a/0x40 fs/jbd2/transaction.c:540
 ocfs2_start_trans+0x376/0x6d0 fs/ocfs2/journal.c:374
 ocfs2_shutdown_local_alloc+0x200/0xa10 fs/ocfs2/localalloc.c:417
 ocfs2_dismount_volume+0x201/0x8d0 fs/ocfs2/super.c:1825
 generic_shutdown_super+0x135/0x2c0 fs/super.c:643
 kill_block_super+0x44/0x90 fs/super.c:1766
 deactivate_locked_super+0xb9/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1378
 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: 0033:0x7fb89498fcd7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe3c1a9578 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fb894a10b55 RCX: 00007fb89498fcd7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe3c1a9630
RBP: 00007ffe3c1a9630 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe3c1aa6c0
R13: 00007fb894a10b55 R14: 0000000000019912 R15: 00007ffe3c1aa700
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/29 22:35 upstream 86aa72182095 ba28e0a8 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-snapshot-upstream-root WARNING in __jbd2_log_wait_for_space
2024/12/30 05:11 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 573067a5a685 d3ccff63 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 WARNING in __jbd2_log_wait_for_space
2024/12/30 04:43 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 573067a5a685 d3ccff63 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 WARNING in __jbd2_log_wait_for_space
2024/12/30 04:15 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 573067a5a685 d3ccff63 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 WARNING in __jbd2_log_wait_for_space
2025/01/04 18:32 upstream 63676eefb7a0 f3558dbf .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs WARNING in __jbd2_log_wait_for_space
2024/12/30 03:40 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 573067a5a685 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __jbd2_log_wait_for_space
* Struck through repros no longer work on HEAD.