From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f80.google.com (mail-io1-f80.google.com [209.85.166.80]) (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 3D7DF32AADD for ; Tue, 21 Oct 2025 10:52:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761043945; cv=none; b=rkEJP+3fHRdn0fPU9duuXERF3DxbagwCM63dO7bzgNmc2SXDVppFQtmYrrzXEyTdNn+Gi9w91z9RgyBCR2Hn+XqrRvmhJbaSm8rIZWW9M/eAouWVqp4BFzUHhF3ztYQ5KZDWEvgBte9W718aWX8Cv2Y0izcwcAkYmNRq/z6NUtk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761043945; c=relaxed/simple; bh=k4+x/4Pc5WbcPGrx/Ued/YG0FZK+SVVlfYq/U4m/crg=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=az66Br+U4yiPmZFl1/sKv4jqHj7EOV8kgjgZ4FeEP5itOQRoi09mX2RlL7vlIjGUV2hUgLNLL88sfG8HUHP38nlzlz7+TQ50cpserK+hDGT79ET9sR8DrGW8ePWnTQ6od4hzMmFlVZU4M46DyRjomRwUu8EIIzZucGmGGEtLjPA= 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=209.85.166.80 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-io1-f80.google.com with SMTP id ca18e2360f4ac-93e4da7a183so512388639f.1 for ; Tue, 21 Oct 2025 03:52:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761043943; x=1761648743; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=XGGkkMNkHmC4tm1IO7kdwE41Uv9388JAygyHw2qBF5E=; b=mxizSU1cJJThMgb45l8hAhMyvKsrOUCB6ZVrUpxNV1Ulk5IjSvxg7Ti/WlSB5iUT1b pN1CY/uIIEjnLuQY93CeCc0nJaQDdLkJVMbUcmEEZphHB2bz+m5mVZf+sDgq+cMH5+tV gv4pu5bUEPPtAy09ws2f4aQfT601AVaoFwgyh3lqwJYqi1cTYs1d/G+f9JCaYeLQ87E6 miagzvE0G6xobYvKDb/H6iumB0PsAvhMc44tzAp3JJEx+NMyYirXtQSr1pMHqLddAZI9 4GdErpE5C/ZWSoG7BrPuEN0JAW8JMIhjj4+xuwfhJy3fRSBZ6YXgR9B9wC+I3MU41HuB crDg== X-Forwarded-Encrypted: i=1; AJvYcCUnYkN4rnPXnWoDvG/K6nyLy6xJDNWbg5EY6MXcqExGcrXTKofZBC1BHBRjIvp/FdgVt5wAmUDOLbzKziU=@vger.kernel.org X-Gm-Message-State: AOJu0Yx29rpYEz0PdK8DdpetkHZjVFBhetifAreNDPZDXCLXPmAVbkQK Mwewc01eCNnL1aFEe0bKVIEhoY09POS4SoyXb5fDOal3vx5DHRzt7Svo6alkDA6tUH02cs38cji ZFLmaz77Ck3N4uLWs2y7ea3p52vZDRt0ZZjpaUltWNtyTpEoTS+a4TWpX4wA= X-Google-Smtp-Source: AGHT+IGZl/z9F3NGvnVY+4zx0T3/5eRzUDTVNeEAVsxrcpu9Kl75QHk4JVAqg9mnWOqdC1rEv0pCnJdsDiI880v7ISAFskicLI5i Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6602:1651:b0:940:d1b4:1089 with SMTP id ca18e2360f4ac-940d1b41221mr1519079439f.1.1761043943425; Tue, 21 Oct 2025 03:52:23 -0700 (PDT) Date: Tue, 21 Oct 2025 03:52:23 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68f765e7.050a0220.346f24.0012.GAE@google.com> Subject: [syzbot] [btrfs?] kernel BUG in btrfs_backref_release_cache (2) From: syzbot To: clm@fb.com, dsterba@suse.com, josef@toxicpanda.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: 98ac9cc4b445 Merge tag 'f2fs-fix-6.18-rc2' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15facb04580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c2d7b4143707d3a0 dashboard link: https://syzkaller.appspot.com/bug?extid=6dafaff006dcd512c3af compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 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-98ac9cc4.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4a2afc96e189/vmlinux-98ac9cc4.xz kernel image: https://storage.googleapis.com/syzbot-assets/92d24cde05de/bzImage-98ac9cc4.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6dafaff006dcd512c3af@syzkaller.appspotmail.com BTRFS info (device loop0): balance: start -d -m BTRFS info (device loop0): relocating block group 6881280 flags data|metadata BTRFS info (device loop0): found 1 extents, stage: move data extents BTRFS info (device loop0): relocating block group 5242880 flags data|metadata BTRFS info (device loop0): found 9 extents, stage: move data extents assertion failed: !cache->nr_nodes :: 0, in fs/btrfs/backref.c:3160 ------------[ cut here ]------------ kernel BUG at fs/btrfs/backref.c:3160! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5319 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~bpo12+1 04/01/2014 RIP: 0010:btrfs_backref_release_cache+0x1ef/0x220 fs/btrfs/backref.c:3160 Code: 0f 0b e8 84 5f d7 fd 48 c7 c7 80 16 b0 8b 48 c7 c6 20 1f b0 8b 31 d2 48 c7 c1 20 17 b0 8b 41 b8 58 0c 00 00 e8 22 9d 3e fd 90 <0f> 0b e8 5a 5f d7 fd 48 c7 c7 80 16 b0 8b 48 c7 c6 60 1f b0 8b 31 RSP: 0018:ffffc9000d5c7830 EFLAGS: 00010246 RAX: 0000000000000043 RBX: ffff88801f4f2020 RCX: 85e0f5a888a8ee00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1bfa650 R12: 1ffff11003e9e421 R13: 00000000fffffffe R14: ffff88801f4f20f0 R15: dffffc0000000000 FS: 00007faaa33d86c0(0000) GS:ffff88808d300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5176a4e949 CR3: 000000001fd36000 CR4: 0000000000352ef0 Call Trace: relocate_block_group+0xac6/0xd70 fs/btrfs/relocation.c:3638 btrfs_relocate_block_group+0x6bc/0xc60 fs/btrfs/relocation.c:3983 btrfs_relocate_chunk+0x12f/0x5c0 fs/btrfs/volumes.c:3451 __btrfs_balance+0x1860/0x23f0 fs/btrfs/volumes.c:4227 btrfs_balance+0xac2/0x11b0 fs/btrfs/volumes.c:4604 btrfs_ioctl_balance+0x3d3/0x610 fs/btrfs/ioctl.c:3577 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+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faaa258efc9 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:00007faaa33d8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007faaa27e6090 RCX: 00007faaa258efc9 RDX: 0000200000000180 RSI: 00000000c4009420 RDI: 0000000000000005 RBP: 00007faaa2611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faaa27e6128 R14: 00007faaa27e6090 R15: 00007ffe79b9d7c8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:btrfs_backref_release_cache+0x1ef/0x220 fs/btrfs/backref.c:3160 Code: 0f 0b e8 84 5f d7 fd 48 c7 c7 80 16 b0 8b 48 c7 c6 20 1f b0 8b 31 d2 48 c7 c1 20 17 b0 8b 41 b8 58 0c 00 00 e8 22 9d 3e fd 90 <0f> 0b e8 5a 5f d7 fd 48 c7 c7 80 16 b0 8b 48 c7 c6 60 1f b0 8b 31 RSP: 0018:ffffc9000d5c7830 EFLAGS: 00010246 RAX: 0000000000000043 RBX: ffff88801f4f2020 RCX: 85e0f5a888a8ee00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1bfa650 R12: 1ffff11003e9e421 R13: 00000000fffffffe R14: ffff88801f4f20f0 R15: dffffc0000000000 FS: 00007faaa33d86c0(0000) GS:ffff88808d300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5176a5bae0 CR3: 000000001fd36000 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