syzbot


WARNING in btrfs_remove_chunk

Status: upstream: reported C repro on 2025/09/12 10:19
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+d81c84c17a84aee2cdcd@syzkaller.appspotmail.com
First crash: 5d01h, last: 11h58m
Bug presence (1)
Date Name Commit Repro Result
2025/09/13 upstream (ToT) 22f20375f5b7 C [report] WARNING in btrfs_remove_chunk
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in btrfs_remove_chunk missing-backport origin:upstream -1 C inconclusive 107 7d11h 914d 0/3 upstream: reported C repro on 2023/03/17 14:37
linux-6.1 WARNING in btrfs_remove_chunk (2) origin:upstream -1 C error 51 23h50m 637d 0/3 upstream: reported C repro on 2023/12/20 03:26
upstream WARNING in btrfs_remove_chunk btrfs -1 C error inconclusive 394 7h00m 1022d 0/29 upstream: reported C repro on 2022/11/30 08:16
linux-6.1 WARNING in btrfs_remove_chunk origin:lts-only -1 C done 10 810d 901d 3/3 fixed on 2023/09/19 11:51

Sample crash report:
BTRFS info (device loop0): block group has cluster?: no
BTRFS info (device loop0): 1 free space entries at or bigger than 4096 bytes
BTRFS info (device loop0): 12447744 bytes available across all block groups
------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: CPU: 0 PID: 6301 at fs/btrfs/volumes.c:3236 btrfs_remove_chunk+0x1601/0x1920 fs/btrfs/volumes.c:3236
Modules linked in:
CPU: 0 PID: 6301 Comm: syz.0.36 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:btrfs_remove_chunk+0x1601/0x1920 fs/btrfs/volumes.c:3236
Code: e8 44 69 cf fd 0f 0b 49 be 00 00 00 00 00 fc ff df e9 8e fd ff ff e8 5e ed 04 fe 48 c7 c7 00 94 ed 8a 44 89 e6 e8 1f 69 cf fd <0f> 0b 49 be 00 00 00 00 00 fc ff df e9 d5 fd ff ff e8 39 ed 04 fe
RSP: 0018:ffffc90004e1f8e0 EFLAGS: 00010246
RAX: 8928c91fe3188900 RBX: 0000000000000000 RCX: ffff888030d40000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90004e1fad0 R08: ffffc90004e1f5e7 R09: 1ffff920009c3ebc
R10: dffffc0000000000 R11: fffff520009c3ebd R12: ffffffffffffffe4
R13: 0000000000000001 R14: ffff88802673c001 R15: 1ffff11005f86170
FS:  00007ff97fded6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff97ef71fe0 CR3: 00000000608a9000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 btrfs_relocate_chunk+0x292/0x3b0 fs/btrfs/volumes.c:3366
 __btrfs_balance+0x187b/0x21c0 fs/btrfs/volumes.c:4067
 btrfs_balance+0xcb1/0x11c0 fs/btrfs/volumes.c:4444
 btrfs_ioctl_balance+0x4a2/0x730 fs/btrfs/ioctl.c:3647
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff97ef8eba9
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:00007ff97fded038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff97f1d5fa0 RCX: 00007ff97ef8eba9
RDX: 0000200000000200 RSI: 00000000c4009420 RDI: 0000000000000004
RBP: 00007ff97f011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff97f1d6038 R14: 00007ff97f1d5fa0 R15: 00007ffc1a4fa6e8
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/12 13:51 linux-6.6.y 60a9e718726f e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-6-6-kasan WARNING in btrfs_remove_chunk
2025/09/16 23:36 linux-6.6.y 60a9e718726f e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in btrfs_remove_chunk
2025/09/16 23:27 linux-6.6.y 60a9e718726f e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in btrfs_remove_chunk
2025/09/12 10:18 linux-6.6.y 60a9e718726f e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in btrfs_remove_chunk
* Struck through repros no longer work on HEAD.