syzbot


kernel BUG in btrfs_exclop_balance

Status: upstream: reported C repro on 2023/06/04 20:48
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+25d31944df2ee34214f5@syzkaller.appspotmail.com
First crash: 354d, last: 177d
Fix commit to backport (bisect log) :
tree: upstream
commit b19c98f237cd76981aaded52c258ce93f7daa8cb
Author: Josef Bacik <josef@toxicpanda.com>
Date: Fri Jun 23 05:05:41 2023 +0000

  btrfs: fix race between balance and cancel/pause

[report pending]
  
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: INFO: rcu detected stall in corrupted (log)
Repro: C syz .config
  
Bug presence (3)
Date Name Commit Repro Result
2023/07/21 linux-6.1.y (ToT) a456e1743881 C [report] kernel BUG in btrfs_exclop_balance
2023/06/05 upstream (ToT) 9561de3a55be C [report] kernel BUG in btrfs_exclop_balance
2023/07/21 upstream (ToT) 57f1f9dd3abe C Didn't crash
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in btrfs_exclop_balance btrfs 1 473d 473d 0/26 closed as invalid on 2023/02/08 16:28
upstream kernel BUG in btrfs_exclop_balance (2) btrfs C error 8 353d 456d 22/26 fixed on 2023/07/01 16:05
Fix bisection attempts (5)
Created Duration User Patch Repo Result
2023/12/11 15:19 8h02m fix candidate upstream job log (1)
2023/11/29 04:43 2h15m bisect fix linux-6.1.y job log (0) log
2023/10/28 19:19 2h02m bisect fix linux-6.1.y job log (0) log
2023/09/26 01:48 2h15m bisect fix linux-6.1.y job log (0) log
2023/07/10 05:35 2h16m bisect fix linux-6.1.y job log (0) log

Sample crash report:
assertion failed: fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED, in fs/btrfs/ioctl.c:454
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.h:3716!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4597 Comm: syz-executor138 Not tainted 6.1.31-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:assertfail+0x18/0x1a fs/btrfs/ctree.h:3716
Code: 0b e8 f7 7c 08 f7 48 c7 c7 60 2f c7 91 e9 9b a7 94 f9 89 f1 48 89 fe 48 c7 c7 c0 56 2e 8b 48 c7 c2 e8 51 2e 8b e8 7c 85 ff ff <0f> 0b 89 f1 48 89 fe 48 c7 c7 00 70 2e 8b 48 c7 c2 20 6b 2e 8b e8
RSP: 0018:ffffc9000b0cfe48 EFLAGS: 00010246
RAX: 0000000000000066 RBX: 1ffff11003569c1c RCX: 7eecb1a9e8baf200
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffffffff816d9a9c R09: fffff52001619f41
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801ab4e0e0
R13: ffff88801ab4c000 R14: ffff88801ab4c688 R15: dffffc0000000000
FS:  00007f7c13737700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab2458f308 CR3: 00000000228ee000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btrfs_exclop_balance+0x145/0x1e0 fs/btrfs/ioctl.c:454
 btrfs_ioctl_balance+0x482/0x7c0 fs/btrfs/ioctl.c:4453
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f7c1b3d1479
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 31 16 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:00007f7c137372f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7c1b461580 RCX: 00007f7c1b3d1479
RDX: 0000000020000540 RSI: 00000000c4009420 RDI: 0000000000000004
RBP: 00007f7c1b428330 R08: 00007f7c13737700 R09: 0000000000000000
R10: 00007f7c13737700 R11: 0000000000000246 R12: 7fffffffffffffff
R13: 0000000100000001 R14: 8000000000000001 R15: 00007f7c1b461588
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:assertfail+0x18/0x1a fs/btrfs/ctree.h:3716
Code: 0b e8 f7 7c 08 f7 48 c7 c7 60 2f c7 91 e9 9b a7 94 f9 89 f1 48 89 fe 48 c7 c7 c0 56 2e 8b 48 c7 c2 e8 51 2e 8b e8 7c 85 ff ff <0f> 0b 89 f1 48 89 fe 48 c7 c7 00 70 2e 8b 48 c7 c2 20 6b 2e 8b e8
RSP: 0018:ffffc9000b0cfe48 EFLAGS: 00010246
RAX: 0000000000000066 RBX: 1ffff11003569c1c RCX: 7eecb1a9e8baf200
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffffffff816d9a9c R09: fffff52001619f41
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801ab4e0e0
R13: ffff88801ab4c000 R14: ffff88801ab4c688 R15: dffffc0000000000
FS:  00007f7c13737700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab2458f308 CR3: 00000000228ee000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/04 20:47 linux-6.1.y d2869ace6eeb a4ae4f42 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan kernel BUG in btrfs_exclop_balance
* Struck through repros no longer work on HEAD.