From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) (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 15A9A383C64 for ; Mon, 2 Mar 2026 20:01:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772481709; cv=none; b=RtZVj4MT/qO1fap+TdUlI9gFxIB28ZMklyqZvwJN+exINkkTmupxXbtgyAqhstzAFPHV5KUNX1+uzLNfUnpMhVvVuqSloFVw12LFZtb6K0mXa+3C5tntsdZ18KMon6gCMO/88Uy9kH359naNXRLq+ySw40ywF9VbJKj2VzWI/l0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772481709; c=relaxed/simple; bh=gDW1mf/SM6xsStA7Z8vSo/fK5nl2CusOU94hPGW/VRo=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=h8pKrdh2zC0mG7jKkD2+EUDpgVYHzDcqUEqUhr5QI+LRkbpzQhTywCKid7j4n+bFAB8z+930zVdniFFCh1yr4cMevclbTQ4e0RCbuX60I0PTfjKTIxZombDpVaGlNhIIU8jiClKWs9A4ya2mgReM6lRXl9FFGDp+5btkUyfyiDw= 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=209.85.161.71 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-oo1-f71.google.com with SMTP id 006d021491bc7-679c54e29f6so25628913eaf.1 for ; Mon, 02 Mar 2026 12:01:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772481703; x=1773086503; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=mxlee0+VtCk5JxrX1yoCNhmITIf/9d+ushv4xvi0o0M=; b=Cu+kkfe/cTTCwiuiRsxigjIT0jCXOTu0bkNyrouvmdsRdPNASeyogsgghsvmnQplU5 oQ4mxAXJZmXwTmh7UIQg9qVE4qFUkc/5osiw/P4/wTUGx+Wz7iL2AXhAdXFkmxAsDduf O37zxDMuiEAwm7HfOQcxqQcEwvdBo0m9XP8DXeLwGHJdieCOfofLJ/pkktY8i/Pw/P5T XxFbVbNTX29RO2WimWN/ramfGEvaRDphChAxvp7mf2whecLy0nUagVHZcBcmGkIgu9Ia 4pP8kbjNvwIpFuYCx1SaJM672Tq3thTIz3pepwntwAlGu7LU8k5qd3Ybz7sEtNjV56T1 5zjg== X-Forwarded-Encrypted: i=1; AJvYcCXzxPDE0E0Zr5qoWZkQvQwIESZscJJL7BmHUEjcGEkbErrVxsE1PWml28sFwmAfavVrMKDvGq60Zj0mJQ==@vger.kernel.org X-Gm-Message-State: AOJu0YyT4L8CbZqDQj/WRQZ4lIe13iGVsMQ7raqafFS99uagF0lANBRb POmRhej3kLl0DdU1C80KEZcVjtM9jGFifibtseRGSDy759iuBOXOCKHx6D5ZyYjeew0q9o5TYiO 9yqbG4+Jw81Eq/Z49ytj2fnsj/EFpZ2UQsR4lz8MBIlGsDIHZODbcsJEp/Uc= Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4de4:b0:667:7e1a:204a with SMTP id 006d021491bc7-679faf91292mr7462782eaf.71.1772481702945; Mon, 02 Mar 2026 12:01:42 -0800 (PST) Date: Mon, 02 Mar 2026 12:01:42 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69a5eca6.a70a0220.b118c.0003.GAE@google.com> Subject: [syzbot] [btrfs?] WARNING: suspicious RCU usage in btrfs_dev_name 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: 7d6661873f6b Add linux-next specific files for 20260226 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=11591952580000 kernel config: https://syzkaller.appspot.com/x/.config?x=98a1e192f758c1c1 dashboard link: https://syzkaller.appspot.com/bug?extid=ba123cf1dd631315ffca 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: https://storage.googleapis.com/syzbot-assets/4cd2824adb8a/disk-7d666187.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/bbdd4a130d86/vmlinux-7d666187.xz kernel image: https://storage.googleapis.com/syzbot-assets/6e3bea3e96f8/bzImage-7d666187.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ba123cf1dd631315ffca@syzkaller.appspotmail.com BTRFS info (device loop1): first mount of filesystem 7e32c2af-f87a-45a1-bcba-64dea7c56a53 BTRFS info (device loop1): using xxhash64 checksum algorithm ============================= WARNING: suspicious RCU usage syzkaller #0 Not tainted ----------------------------- fs/btrfs/volumes.h:872 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz.1.21/6007: #0: ffff8880346a60e0 (&type->s_umount_key#58/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345 stack backtrace: CPU: 0 UID: 0 PID: 6007 Comm: syz.1.21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x13f/0x1d0 kernel/locking/lockdep.c:6876 btrfs_dev_name+0x128/0x130 fs/btrfs/volumes.h:872 btrfs_repair_io_failure+0x4f8/0x6a0 fs/btrfs/bio.c:989 btrfs_repair_eb_io_failure fs/btrfs/disk-io.c:198 [inline] btrfs_read_extent_buffer+0xb84/0xcd0 fs/btrfs/disk-io.c:245 read_tree_block fs/btrfs/disk-io.c:592 [inline] read_tree_root_path+0x29d/0x840 fs/btrfs/disk-io.c:988 load_global_roots_objectid+0x431/0xa20 fs/btrfs/disk-io.c:2095 load_global_roots fs/btrfs/disk-io.c:2135 [inline] btrfs_read_roots fs/btrfs/disk-io.c:2160 [inline] init_tree_roots+0xbe2/0x2240 fs/btrfs/disk-io.c:2712 open_ctree+0x1960/0x2e40 fs/btrfs/disk-io.c:3489 btrfs_fill_super+0x187/0x2e0 fs/btrfs/super.c:981 btrfs_get_tree_super fs/btrfs/super.c:1944 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline] btrfs_get_tree+0xe77/0x1370 fs/btrfs/super.c:2121 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3839 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f30d979da0a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f30da6dee58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f30da6deee0 RCX: 00007f30d979da0a RDX: 00002000000002c0 RSI: 0000200000000680 RDI: 00007f30da6deea0 RBP: 00002000000002c0 R08: 00007f30da6deee0 R09: 0000000001a001d8 R10: 0000000001a001d8 R11: 0000000000000246 R12: 0000200000000680 R13: 00007f30da6deea0 R14: 000000000002223e R15: 0000200000000000 BTRFS info (device loop1): read error corrected: ino 0 off 30670848 (dev /dev/loop1 sector 76288) BTRFS info (device loop1): read error corrected: ino 0 off 30687232 (dev /dev/loop1 sector 76320) BTRFS info (device loop1): read error corrected: ino 0 off 30523392 (dev /dev/loop1 sector 76000) BTRFS info (device loop1): read error corrected: ino 0 off 30457856 (dev /dev/loop1 sector 75872) BTRFS info (device loop1): deleted orphan free space tree entries BTRFS info (device loop1): checking UUID tree BTRFS info (device loop1): turning on sync discard BTRFS info (device loop1): enabling free space tree --- 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