loop0: detected capacity change from 0 to 32768
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/bcachefs/super-io.c:290:18
shift exponent 255 is too large for 32-bit type 'int'
CPU: 0 UID: 0 PID: 5095 Comm: syz-executor156 Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468
 validate_sb_layout+0xafa/0xb10 fs/bcachefs/super-io.c:290
 bch2_sb_validate+0x8e4/0xf70 fs/bcachefs/super-io.c:442
 __bch2_read_super+0xc24/0x1380 fs/bcachefs/super-io.c:832
 bch2_fs_open+0x270/0x2f80 fs/bcachefs/super.c:2032
 bch2_fs_get_tree+0x738/0x1710 fs/bcachefs/fs.c:2161
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efc36576dea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff737695c8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff737695e0 RCX: 00007efc36576dea
RDX: 00000000200058c0 RSI: 0000000020005900 RDI: 00007fff737695e0
RBP: 0000000000000004 R08: 00007fff73769620 R09: 00000000000058e0
R10: 0000000000010000 R11: 0000000000000282 R12: 0000000000010000
R13: 00007fff73769620 R14: 0000000000000003 R15: 0000000001000000
 </TASK>
---[ end trace ]---