------------[ cut here ]------------
WARNING: CPU: 1 PID: 7204 at fs/bcachefs/super.c:1253 bch2_dev_free+0x27f/0x2d0 fs/bcachefs/super.c:1253
Modules linked in:
CPU: 1 UID: 0 PID: 7204 Comm: syz.3.395 Not tainted 6.15.0-rc6-syzkaller-00278-g172a9d94339c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:bch2_dev_free+0x27f/0x2d0 fs/bcachefs/super.c:1253
Code: 02 89 ee e8 23 b1 5c fd 40 84 ed 0f 84 de fe ff ff e9 cc fe ff ff e8 30 b6 5c fd 90 0f 0b 90 e9 e4 fd ff ff e8 22 b6 5c fd 90 <0f> 0b 90 e9 ae fd ff ff 4c 89 f7 e8 f1 3d c1 fd e9 05 fe ff ff e8
RSP: 0018:ffffc900039cf238 EFLAGS: 00010283
RAX: 0000000000062210 RBX: ffff88805e95a000 RCX: ffffc9000cb7b000
RDX: 0000000000080000 RSI: ffffffff845e8f6e RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88805e95a0c0
R13: ffffc900039cf398 R14: ffff88805e95a000 R15: ffffc900039cf340
FS:  00007fe37c1b36c0(0000) GS:ffff888124ae0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f308d57d2d8 CR3: 000000007834c000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __bch2_dev_alloc+0xa4e/0xe80 fs/bcachefs/super.c:1422
 bch2_dev_alloc+0xb8/0x170 fs/bcachefs/super.c:1448
 bch2_fs_alloc+0x1b43/0x2470 fs/bcachefs/super.c:960
 bch2_fs_open+0x78e/0xb40 fs/bcachefs/super.c:2210
 bch2_fs_get_tree+0x104d/0x1860 fs/bcachefs/fs.c:2491
 vfs_get_tree+0x8e/0x340 fs/super.c:1759
 do_new_mount fs/namespace.c:3881 [inline]
 path_mount+0x14d4/0x1f20 fs/namespace.c:4208
 do_mount fs/namespace.c:4221 [inline]
 __do_sys_mount fs/namespace.c:4432 [inline]
 __se_sys_mount fs/namespace.c:4409 [inline]
 __x64_sys_mount+0x28d/0x310 fs/namespace.c:4409
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe37b39010a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe37c1b2e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe37c1b2ef0 RCX: 00007fe37b39010a
RDX: 0000200000000080 RSI: 0000200000000000 RDI: 00007fe37c1b2eb0
RBP: 0000200000000080 R08: 00007fe37c1b2ef0 R09: 0000000000800000
R10: 0000000000800000 R11: 0000000000000246 R12: 0000200000000000
R13: 00007fe37c1b2eb0 R14: 0000000000005903 R15: 0000200000000180
 </TASK>