WARNING in btrfs_quota_enable (2)

Status: upstream: reported syz repro on 2026/10/31 18:48
Reported-by: syzbot+b450b6b7888d22583e2a@syzkaller.appspotmail.com
First crash: 12d, last: 7d04h
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in btrfs_quota_enable origin:upstream -1 syz, C error 8 19d 1085d 0/3 upstream: reported C repro on 2023/11/24 03:47
upstream WARNING in btrfs_quota_enable btrfs -1 1 1174d 1170d 0/29 auto-obsoleted due to no activity on 2023/12/05 05:27
linux-6.6 WARNING in btrfs_quota_enable -1 syz, C 1 2d03h 2d03h 0/2 upstream: reported C repro on 2026/11/11 10:02
linux-6.1 WARNING in btrfs_quota_enable -1 1 380d 380d 0/3 auto-obsoleted due to no activity on 2026/02/06 00:31
linux-4.19 WARNING in btrfs_quota_enable btrfs -1 syz, C error 4 1357d 1429d 0/1 upstream: reported C repro on 2022/12/15 10:06
upstream WARNING in btrfs_quota_enable (2) prio:low btrfs -1 17 3d04h 79d 0/29 upstream: reported on 2026/08/25 15:41

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5410 at fs/btrfs/qgroup.c:1042 btrfs_quota_enable+0x1848/0x1c60 fs/btrfs/qgroup.c:1042
Modules linked in:
CPU: 0 PID: 5410 Comm: syz.2.149 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:btrfs_quota_enable+0x1848/0x1c60 fs/btrfs/qgroup.c:1042
Code: 00 00 4c 89 e7 e8 48 19 51 fe e9 8c e9 ff ff e8 0e a4 b4 06 e8 a9 b4 ff fd 48 c7 c7 c0 5c f0 8a 48 8b 74 24 18 e8 58 16 cb fd <0f> 0b e9 45 f9 ff ff e8 8c b4 ff fd 48 c7 c7 c0 5c f0 8a be f4 ff
RSP: 0018:ffffc900061ffcc0 EFLAGS: 00010246
RAX: a8bb5ea6f116ef00 RBX: ffff88807355da28 RCX: ffff888027ad3c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc900061ffea0 R08: ffffc900061ff947 R09: 1ffff92000c3ff28
R10: dffffc0000000000 R11: fffff52000c3ff29 R12: ffff8880296f8001
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100e6abb45
FS:  00007fac722036c0(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fac713ed200 CR3: 0000000028138000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btrfs_ioctl_quota_ctl+0x13a/0x170 fs/btrfs/ioctl.c:4646
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fac7139fb19
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fac72203028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fac71626090 RCX: 00007fac7139fb19
RDX: 0000200000006380 RSI: 00000000c0109428 RDI: 0000000000000003
RBP: 00007fac71437b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fac71626128 R14: 00007fac71626090 R15: 00007ffdbc64cbc8
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/06 08:38 linux-6.1.y 08889840163e 5cecaf1f .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-6-1-kasan WARNING in btrfs_quota_enable
2026/10/31 18:48 linux-6.1.y 08889840163e 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in btrfs_quota_enable
2026/10/31 18:47 linux-6.1.y 08889840163e 2041d3f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in btrfs_quota_enable
* Struck through repros no longer work on HEAD.