[syzbot] [btrfs?] WARNING in btrfs_init_new_device

[syzbot] [btrfs?] WARNING in btrfs_init_new_device

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    848acc8ffe1b Merge tag 'fsverity-for-linus' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17e65bb9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b7079b368dcec295
dashboard link: https://syzkaller.appspot.com/bug?extid=3bf3e110b2d406b8166c
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/25bde0bfecb5/disk-848acc8f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8a5ebf809884/vmlinux-848acc8f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1d1810845ac3/bzImage-848acc8f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3bf3e110b2d406b8166c@syzkaller.appspotmail.com

kobject: kobject_add_internal failed for 2 with -EEXIST, don't try to register things with the same name in the same directory.
BTRFS warning (device loop7): devinfo init for devid 2 failed: -17
------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/volumes.c:3013 at btrfs_init_new_device+0x1fc6/0x3e70 fs/btrfs/volumes.c:3013, CPU#1: syz.7.121/6685
Modules linked in:
CPU: 1 UID: 0 PID: 6685 Comm: syz.7.121 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:btrfs_init_new_device+0x1fc6/0x3e70 fs/btrfs/volumes.c:3013
Code: fd 48 c7 c6 60 79 29 8c e8 97 62 a4 fd 8d 45 1e 83 f8 19 77 0f ba 01 00 04 02 48 0f a3 c2 0f 82 94 8b ca fc e8 ab 67 a4 fd 90 <0f> 0b 90 e9 86 8b ca fc e8 9d 67 a4 fd 48 8b 7c 24 40 e8 e3 81 f3
RSP: 0018:ffffc90005627960 EFLAGS: 00010283
RAX: 0000000000030d92 RBX: ffff88807adf0000 RCX: ffffc9002560b000
RDX: 0000000000080000 RSI: ffffffff8465ec15 RDI: ffff8880207d0000
RBP: 00000000ffffffef R08: 0000000000000005 R09: fffffffffffffffb
R10: ffffffffffffffef R11: 0000000000000000 R12: ffff888079bb4a80
R13: ffff88807adf1c00 R14: ffff88802bc92000 R15: ffff88805186c5e0
FS:  00007f40c8b946c0(0000) GS:ffff888123ed9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7e4921b1d4 CR3: 000000002d0c8000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 btrfs_ioctl_add_dev+0x34a/0x5f0 fs/btrfs/ioctl.c:2558
 btrfs_ioctl+0xce8/0x5d10 fs/btrfs/ioctl.c:5529
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f40c7d9e019
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:00007f40c8b94028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f40c8026090 RCX: 00007f40c7d9e019
RDX: 00002000000023c0 RSI: 000000005000940a RDI: 0000000000000009
RBP: 00007f40c7e3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f40c8026128 R14: 00007f40c8026090 R15: 00007fff8c42dc38
 </TASK>


---
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Re: [syzbot] [btrfs?] WARNING in btrfs_init_new_device

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    3d6d817622b0 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13705149580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=158601bb8cb292dd
dashboard link: https://syzkaller.appspot.com/bug?extid=3bf3e110b2d406b8166c
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13d3ec79580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=100c8ac6580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fc778852603e/disk-3d6d8176.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/05372451f9a9/vmlinux-3d6d8176.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0620f51f7bde/bzImage-3d6d8176.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/99b4705403e2/mount_0.gz
  fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=17f48ac6580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3bf3e110b2d406b8166c@syzkaller.appspotmail.com

------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/volumes.c:3013 at btrfs_init_new_device+0x1913/0x19e0 fs/btrfs/volumes.c:3013, CPU#1: syz.0.17/5924
Modules linked in:
CPU: 1 UID: 0 PID: 5924 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:btrfs_init_new_device+0x1913/0x19e0 fs/btrfs/volumes.c:3013
Code: 00 00 41 83 fe f4 0f 85 d8 00 00 00 e8 d6 c3 b4 fd e9 d7 00 00 00 e8 cc c3 b4 fd eb 10 e8 c5 c3 b4 fd eb 09 e8 be c3 b4 fd 90 <0f> 0b 90 44 89 f1 f7 d9 e9 7b fc ff ff 89 d9 80 e1 07 38 c1 0f 8c
RSP: 0018:ffffc90003f07da8 EFLAGS: 00010293
RAX: ffffffff84110472 RBX: ffff8880357dc001 RCX: ffff8880381a5d00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffff8880381a5d00 R09: 0000000000000003
R10: 0000000000000100 R11: 00000000fffffffb R12: ffff8880357dce40
R13: 0000000000000001 R14: 00000000ffffffef R15: ffff8880357dc000
FS:  00007fc65910e6c0(0000) GS:ffff888125d46000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc659afb7c0 CR3: 00000000472b8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 btrfs_ioctl_add_dev+0x1ad/0x640 fs/btrfs/ioctl.c:2558
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xff/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: 0033:0x7fc659aae0d9
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:00007fc65910e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc659d35fa0 RCX: 00007fc659aae0d9
RDX: 0000200000001000 RSI: 000000005000940a RDI: 0000000000000004
RBP: 00007fc659b45024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc659d36038 R14: 00007fc659d35fa0 R15: 00007fff92859458
 </TASK>


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