WARNING in btrfs_put_block_group

Status: auto-obsoleted due to no activity on 2026/08/03 06:58
Subsystems: btrfs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+e38c6fff39c0d7d6f121@syzkaller.appspotmail.com
First crash: 1207d, last: 149d
Cause bisection: introduced by (bisect log) [merge commit]:
commit f8566aa4f1766bb0267b7a0ed89c1d2c4a82ee1a
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sat Jul 1 18:40:01 2023 +0000

  Merge tag 'x86-urgent-2023-07-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Crash: WARNING in btrfs_put_block_group (log)
Repro: C syz .config
  
Fix bisection: failed (error log, bisect log)
  
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
00f4b27c assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in btrfs_put_block_group 2026/05/17 22:13 2026/05/17 22:13 2026/05/17 22:58 de5aae85
Discussions (6)
Title Replies (including bot) Last reply
[syzbot] Monthly btrfs report (Oct 2025) 0 (1) 2025/10/27 12:50
[syzbot] Monthly btrfs report (Nov 2024) 0 (1) 2024/11/18 10:39
[syzbot] Monthly btrfs report (Oct 2024) 0 (1) 2024/10/17 07:41
[syzbot] Monthly btrfs report (Sep 2024) 0 (1) 2024/09/16 12:27
[syzbot] Monthly btrfs report (Jul 2024) 0 (1) 2024/07/15 14:03
[syzbot] [btrfs?] WARNING in btrfs_put_block_group 0 (2) 2023/11/07 15:19
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in btrfs_put_block_group origin:lts-only -1 syz, C error 76 6d18h 1231d 0/3 upstream: reported C repro on 2023/03/29 11:09
Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/08/03 06:22 34m retest repro upstream no crash log
2026/05/24 18:42 25m retest repro upstream log
2026/03/15 15:36 44m retest repro upstream report log
2026/01/04 14:07 42m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci no crash log
2026/01/04 13:46 20m retest repro upstream error
2025/11/04 11:39 22m retest repro upstream no crash log
2025/09/10 19:16 23m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/08/12 22:55 25m retest repro upstream report log
2025/08/10 19:11 26m retest repro upstream no crash log
2025/05/16 13:52 53m retest repro upstream report log
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2026/03/15 09:19 4m bisect fix upstream error job log
2024/08/04 08:49 2h25m bisect fix upstream OK (0) job log log
2024/01/05 18:36 5h18m bisect fix upstream OK (0) job log log

Sample crash report:
BTRFS info (device loop4): last unmount of filesystem c9fe44da-de57-406a-8241-57ec7d4412cf
BTRFS info (device loop4): at unmount dio bytes count 69632
------------[ cut here ]------------
cache->reserved > 0
WARNING: fs/btrfs/block-group.c:172 at btrfs_put_block_group+0x305/0x360 fs/btrfs/block-group.c:172, CPU#0: syz-executor/5796
Modules linked in:
CPU: 0 UID: 0 PID: 5796 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:btrfs_put_block_group+0x305/0x360 fs/btrfs/block-group.c:172
Code: 42 80 3c 20 00 74 08 48 89 df e8 46 06 29 fe bf 48 20 00 00 48 03 3b 48 89 de e8 76 cd 01 00 e9 c0 fe ff ff e8 bc ec c3 fd 90 <0f> 0b 90 e9 84 fe ff ff e8 ae ec c3 fd e9 7a fe ff ff e8 a4 ec c3
RSP: 0018:ffffc900049d7a98 EFLAGS: 00010293
RAX: ffffffff83ff28c4 RBX: ffff888034781800 RCX: ffff888039e90000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10077f2497 R12: dffffc0000000000
R13: ffff888034781b64 R14: 0000000000011000 R15: dffffc0000000000
FS:  0000555562a18500(0000) GS:ffff888126595000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc70df4e223 CR3: 0000000043d04000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 btrfs_free_block_groups+0xd36/0x1110 fs/btrfs/block-group.c:4665
 close_ctree+0x7b4/0x13b0 fs/btrfs/disk-io.c:4456
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_anon_super+0x3b/0x70 fs/super.c:1292
 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2127
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fec0f9dd1d7
Code: a2 c7 05 bc e3 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 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 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe18896e08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fec0fa71c3b RCX: 00007fec0f9dd1d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe18896ec0
RBP: 00007ffe18896ec0 R08: 00007ffe18897ec0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe18897f50
R13: 00007fec0fa71c3b R14: 00000000000267f4 R15: 00007ffe18897f90
 </TASK>

Crashes (195):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/13 09:04 upstream c22e26bd0906 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2026/02/13 06:40 upstream c22e26bd0906 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2026/01/23 06:01 upstream c072629f05d7 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2026/01/19 15:39 upstream 24d479d26b25 a9fc5226 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2026/01/12 10:55 upstream 9c7ef209cd0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2026/01/11 09:49 upstream 97313d6113ab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2026/01/11 09:41 upstream 97313d6113ab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/11/30 13:25 upstream 6bda50f4333f d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-upstream-kasan-gce-root WARNING in btrfs_put_block_group
2025/11/30 11:20 upstream 6bda50f4333f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in btrfs_put_block_group
2025/11/17 02:53 upstream 7254a2b52279 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/11/05 08:02 upstream 284922f4c563 a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/10/20 12:13 upstream 211ddde0823f 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/08/27 18:41 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in btrfs_put_block_group
2025/07/27 18:22 upstream ec2df4364666 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/07/19 11:51 upstream 4871b7cb27f4 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/07/19 02:44 upstream d786aba32000 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/07/04 12:48 upstream 4c06e63b9203 76ad128c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/07/04 02:38 upstream 17bbde2e1716 76ad128c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/06/22 14:59 upstream 739a6c93cc75 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/06/08 10:55 upstream 8630c59e9936 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/05/30 15:19 upstream f66bc387efbe 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/05/28 14:18 upstream feacb1774bd5 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/05/27 14:37 upstream 785cdec46e92 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/05/20 01:54 upstream a5806cd506af b84f0537 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/05/02 11:41 upstream ebd297a2affa d7f099d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/26 20:32 upstream f1a3944c860b c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/22 13:22 upstream a33b5a08cbbd 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/22 12:15 upstream a33b5a08cbbd 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/14 14:07 upstream 8ffd015db85f 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/13 20:07 upstream 5aaaedb0cb54 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/13 16:24 upstream 5aaaedb0cb54 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/13 10:20 upstream 7cdabafc0012 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/12 12:40 upstream 3bde70a2c827 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/11 12:09 upstream 900241a5cc15 94486846 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/10 21:18 upstream 2eb959eeecc6 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/04/10 19:39 upstream 2eb959eeecc6 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/03/24 04:18 upstream 586de92313fc 875573af .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/03/24 00:17 upstream 586de92313fc 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/03/15 05:15 upstream a29967be967e e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/02/28 18:47 upstream 76544811c850 67cf5345 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2024/05/02 15:22 upstream 0106679839f7 3ba885bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in btrfs_put_block_group
2023/11/07 15:19 upstream be3ca57cfb77 83211397 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-root WARNING in btrfs_put_block_group
2024/06/07 13:18 upstream 8a92980606e3 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in btrfs_put_block_group
2024/06/13 11:11 upstream 2ccbdf43d5e7 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in btrfs_put_block_group
2023/04/22 11:33 upstream 8e41e0a57566 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in btrfs_put_block_group
2025/07/02 08:11 linux-next 1343433ed389 ffe4b334 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in btrfs_put_block_group
2026/01/28 22:14 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 59e4d31a0470 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/12/21 13:45 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f0b4cce4481 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/12/14 05:51 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 05c93f3395ed d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/10/07 10:40 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bf45a62baffc 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/10/05 20:39 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bf45a62baffc 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/08/24 09:19 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/08/14 06:20 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 22ec1469 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/08/14 04:34 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/07/11 09:44 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ec4801305969 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/05/23 03:27 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d7fa1af5b33e fa44301a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
2025/02/09 20:28 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2014c95afece ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in btrfs_put_block_group
* Struck through repros no longer work on HEAD.