loop0: detected capacity change from 0 to 512
------------[ cut here ]------------
kernel BUG at fs/buffer.c:2714!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1960 Comm: syz.0.407 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:submit_bh_wbc+0x4c9/0x4f0 fs/buffer.c:2714
Code: c3 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c bd fe ff ff 48 89 df e8 08 36 e8 ff e9 b0 fe ff ff e8 9e bc a3 ff 0f 0b e8 97 bc a3 ff <0f> 0b e8 90 bc a3 ff 0f 0b e8 89 bc a3 ff 0f 0b e8 82 bc a3 ff 0f
RSP: 0018:ffffc90002c777a0 EFLAGS: 00010283
RAX: ffffffff81cc6de9 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc900015ca000 RSI: 0000000000001712 RDI: 0000000000001713
RBP: ffffc90002c777f0 R08: dffffc0000000000 R09: ffffed102658b5cf
R10: ffffed102658b5cf R11: 1ffff1102658b5ce R12: 0000000000000000
R13: 1ffff1102658b5ce R14: ffff888132c5ae70 R15: 0000000000003000
FS:  00007f7a5c9ea6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 00000001210bf000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 submit_bh+0x1f/0x30 fs/buffer.c:2755
 __ext4_read_bh fs/ext4/super.c:175 [inline]
 ext4_read_bh+0x18c/0x220 fs/ext4/super.c:199
 read_mmp_block+0x15f/0x6d0 fs/ext4/mmp.c:97
 ext4_multi_mount_protect+0x583/0x950 fs/ext4/mmp.c:378
 __ext4_fill_super fs/ext4/super.c:5277 [inline]
 ext4_fill_super+0x4bf0/0x7970 fs/ext4/super.c:5655
 get_tree_bdev+0x444/0x680 fs/super.c:1368
 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5685
 vfs_get_tree+0x9a/0x270 fs/super.c:1575
 do_new_mount+0x25a/0xa20 fs/namespace.c:3078
 path_mount+0x675/0x1010 fs/namespace.c:3408
 do_mount fs/namespace.c:3421 [inline]
 __do_sys_mount fs/namespace.c:3629 [inline]
 __se_sys_mount+0x318/0x380 fs/namespace.c:3606
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3606
 x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7a5bb90eea
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:00007f7a5c9e9e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f7a5c9e9ef0 RCX: 00007f7a5bb90eea
RDX: 00002000000004c0 RSI: 0000200000000500 RDI: 00007f7a5c9e9eb0
RBP: 00002000000004c0 R08: 00007f7a5c9e9ef0 R09: 0000000000000008
R10: 0000000000000008 R11: 0000000000000246 R12: 0000200000000500
R13: 00007f7a5c9e9eb0 R14: 0000000000000523 R15: 0000200000000080
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:submit_bh_wbc+0x4c9/0x4f0 fs/buffer.c:2714
Code: c3 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c bd fe ff ff 48 89 df e8 08 36 e8 ff e9 b0 fe ff ff e8 9e bc a3 ff 0f 0b e8 97 bc a3 ff <0f> 0b e8 90 bc a3 ff 0f 0b e8 89 bc a3 ff 0f 0b e8 82 bc a3 ff 0f
RSP: 0018:ffffc90002c777a0 EFLAGS: 00010283
RAX: ffffffff81cc6de9 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc900015ca000 RSI: 0000000000001712 RDI: 0000000000001713
RBP: ffffc90002c777f0 R08: dffffc0000000000 R09: ffffed102658b5cf
R10: ffffed102658b5cf R11: 1ffff1102658b5ce R12: 0000000000000000
R13: 1ffff1102658b5ce R14: ffff888132c5ae70 R15: 0000000000003000
FS:  00007f7a5c9ea6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 00000001210bf000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400