From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f77.google.com (mail-ot1-f77.google.com [209.85.210.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1720B19EED3 for ; Wed, 17 Jun 2026 01:33:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781660015; cv=none; b=BiBSgElTVVe94Bs1McGycGl6VHqh3cBi/LlwvkWy9OL80A0ow4KDNjoKrV2uncEs/BmVi2t2HpJQ+pPzBe7FDrx1kAprb5ocMN0ybvQdgD0yTLBD3GZ39+nwsTz8IKrfLWxGK23SSQ2CuvdJ/+PWwcaZZlsPh8F9uzcUrENSB0Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781660015; c=relaxed/simple; bh=mRv7Eqs7EXZZH4CAmy0L5rN+q2ad8wI/2KEOwHRzLOo=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=NhSP+TbqS+bIQSVLNqkmqAKn9GhZrxRGa46gRTyAsd4+v8AKsSF7KbBycztTNcaQ7cOdy9qy4pwTDCwo2H2uDpjFInQ5BPkoa6nX8cuFp0hoyxtFlgojgPIK/7sFJfrxa16+QKbXIH7CJMI6x/nihJg9pJOuEQvY7sri2z6Oc00= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.210.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-ot1-f77.google.com with SMTP id 46e09a7af769-7e6cb279950so10354663a34.1 for ; Tue, 16 Jun 2026 18:33:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781660013; x=1782264813; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=9+ggiXFVPEh/C4DsLvAL8y9CgmsmMf1deiPtKj4kPAE=; b=Q1sXbVuHcWCzMJwbF08EaHBbLmZsE67tccgnpu3B3j1OPzZ+NFaIsZWwVmGw3oJ5/y OdcEAYNPnTNoCT3u3Wqba92cpap+xiXbCtP1h7G2PmzVp7EIdXpNDsZdw5BdIo6dyHjy iz+yUR7u0RpDL1/M0OrMbVFnpjr+RewXueEW/iWSmuG7BuF9c6UOxuiglxWf+8aG8Ptx Ag5bEwx4cTwok9zDmvzBtOEAJL+BVac1xvC47AhJN43Y0+XZmbFovuDARzT6P+ds1CpI F/3dLwHXA1qMk/vXLjPnDog/za+Q4zyPO+pKQIAtM2cDIZbMR17hHo0E7+cTfTAzOJCV 1uSw== X-Forwarded-Encrypted: i=1; AFNElJ9l6XNVK8C6XX8bLJMpELAfMcHbRSod7Oz1zjAd/3St7xkVe0RMIfNGPPVePPkIddt9hoHLwg11DkujxO8=@vger.kernel.org X-Gm-Message-State: AOJu0YwfMDY0tnTpwz3sdBytDhsrGiOD0OG7sF0VIzgOP95NgItRPrnS rXsIWC6nVGC3WKMnHVUAHVGsT7JJhy+quwC41OYXFKbNn23eDn2z7TiYWZwt0Z6Gsv6TKTnRiTj RK76hLnyVlbC5YZyVeW/ifp65AFNUw60QBkHDrY5aQ0Ad9ycPOh83p2hPftg= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1797:b0:45c:8fa8:7497 with SMTP id 5614622812f47-489429eea8fmr1733053b6e.34.1781660013093; Tue, 16 Jun 2026 18:33:33 -0700 (PDT) Date: Tue, 16 Jun 2026 18:33:33 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a31f96d.d1b4d54b.11ef78.002d.GAE@google.com> Subject: [syzbot] [btrfs?] kernel BUG in btrfs_balance From: syzbot To: clm@fb.com, dsterba@suse.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 1dadb7e7eb5a Merge tag 'sound-7.1' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10eb83b6580000 kernel config: https://syzkaller.appspot.com/x/.config?x=b4166e8ea5fbf7e3 dashboard link: https://syzkaller.appspot.com/bug?extid=dc9291cf132691aeb478 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-1dadb7e7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/83a43e146e33/vmlinux-1dadb7e7.xz kernel image: https://storage.googleapis.com/syzbot-assets/758209a3afac/bzImage-1dadb7e7.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+dc9291cf132691aeb478@syzkaller.appspotmail.com loop0: detected capacity change from 0 to 32768 btrfs: Deprecated parameter 'usebackuproot' BTRFS warning: 'usebackuproot' is deprecated, use 'rescue=usebackuproot' instead BTRFS: device fsid c9fe44da-de57-406a-8241-57ec7d4412cf devid 1 transid 8 /dev/loop0 (7:0) scanned by syz.0.0 (5338) BTRFS info (device loop0): first mount of filesystem c9fe44da-de57-406a-8241-57ec7d4412cf BTRFS info (device loop0): using crc32c checksum algorithm BTRFS info (device loop0): rebuilding free space tree BTRFS info (device loop0): setting nodatasum BTRFS info (device loop0): allowing degraded mounts BTRFS info (device loop0): setting nodatacow BTRFS info (device loop0): enabling ssd optimizations BTRFS info (device loop0): using spread ssd allocation scheme BTRFS info (device loop0): turning on flush-on-commit BTRFS info (device loop0): turning on async discard BTRFS info (device loop0): enabling free space tree BTRFS info (device loop0): force clearing of disk cache BTRFS info (device loop0): trying to use backup root at mount time FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 UID: 0 PID: 5338 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x412/0x560 lib/fault-inject.c:174 should_failslab+0xa8/0x100 mm/failslab.c:46 slab_pre_alloc_hook mm/slub.c:4523 [inline] slab_alloc_node mm/slub.c:4876 [inline] kmem_cache_alloc_noprof+0x87/0x650 mm/slub.c:4906 btrfs_start_dirty_block_groups+0x340/0x10b0 fs/btrfs/block-group.c:3567 btrfs_commit_transaction+0x375/0x2fc0 fs/btrfs/transaction.c:2291 insert_balance_item+0xcd7/0x1610 fs/btrfs/volumes.c:3834 btrfs_balance+0x7d2/0x11b0 fs/btrfs/volumes.c:4874 btrfs_ioctl_balance+0x3d3/0x610 fs/btrfs/ioctl.c:3453 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1f1d19ce59 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:00007f1f1e011fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1f1d415fa0 RCX: 00007f1f1d19ce59 RDX: 0000200000000180 RSI: 00000000c4009420 RDI: 0000000000000008 RBP: 00007f1f1e012050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007f1f1d416038 R14: 00007f1f1d415fa0 R15: 00007ffd7ed8ab98 ------------[ cut here ]------------ kernel BUG at fs/btrfs/volumes.c:4879! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5338 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:btrfs_balance+0x1196/0x11b0 fs/btrfs/volumes.c:4879 Code: c9 fd 48 c7 c7 60 42 17 8c 48 c7 c6 20 4c 17 8c 48 c7 c2 e0 3f 17 8c b9 1b 13 00 00 e8 33 91 2b fd 90 0f 0b e8 3b ab c9 fd 90 <0f> 0b e8 33 ab c9 fd 90 0f 0b e8 2b ab c9 fd 90 0f 0b 0f 1f 84 00 RSP: 0018:ffffc900036efd70 EFLAGS: 00010293 RAX: ffffffff83fc1bd5 RBX: 0000000000000000 RCX: ffff88801ce1ca80 RDX: 0000000000000000 RSI: 00000000ffffffef RDI: 00000000ffffffef RBP: 00000000ffffffef R08: ffff88801ce1ca80 R09: 0000000000000002 R10: 00000000ffffffef R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880418a0000 R14: ffff8880121a2400 R15: 1ffff11008314002 FS: 00007f1f1e0126c0(0000) GS:ffff88808c894000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1f111ff000 CR3: 000000001f443000 CR4: 0000000000352ef0 Call Trace: btrfs_ioctl_balance+0x3d3/0x610 fs/btrfs/ioctl.c:3453 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1f1d19ce59 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:00007f1f1e011fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1f1d415fa0 RCX: 00007f1f1d19ce59 RDX: 0000200000000180 RSI: 00000000c4009420 RDI: 0000000000000009 RBP: 00007f1f1d232d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1f1d416038 R14: 00007f1f1d415fa0 R15: 00007ffd7ed8ab98 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:btrfs_balance+0x1196/0x11b0 fs/btrfs/volumes.c:4879 Code: c9 fd 48 c7 c7 60 42 17 8c 48 c7 c6 20 4c 17 8c 48 c7 c2 e0 3f 17 8c b9 1b 13 00 00 e8 33 91 2b fd 90 0f 0b e8 3b ab c9 fd 90 <0f> 0b e8 33 ab c9 fd 90 0f 0b e8 2b ab c9 fd 90 0f 0b 0f 1f 84 00 RSP: 0018:ffffc900036efd70 EFLAGS: 00010293 RAX: ffffffff83fc1bd5 RBX: 0000000000000000 RCX: ffff88801ce1ca80 RDX: 0000000000000000 RSI: 00000000ffffffef RDI: 00000000ffffffef RBP: 00000000ffffffef R08: ffff88801ce1ca80 R09: 0000000000000002 R10: 00000000ffffffef R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880418a0000 R14: ffff8880121a2400 R15: 1ffff11008314002 FS: 00007f1f1e0126c0(0000) GS:ffff88808c894000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055697aa6da80 CR3: 000000001f443000 CR4: 0000000000352ef0 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup