------------[ cut here ]------------
kernel BUG at fs/buffer.c:579!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4378 Comm: syz.0.1 Not tainted 6.1.124-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:mark_buffer_dirty_inode+0x2f1/0x300 fs/buffer.c:579
Code: e8 34 be e0 ff 48 8b 44 24 10 49 89 06 48 8b 7c 24 18 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d e9 04 9a bb 08 e8 6f 27 89 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 41 57 41 56 41 55
RSP: 0018:ffffc90004a3efc0 EFLAGS: 00010283
RAX: ffffffff82017491 RBX: ffff8880555b0588 RCX: 0000000000080000
RDX: ffffc900056d1000 RSI: 000000000002cce8 RDI: 000000000002cce9
RBP: 1ffff1100aab60b1 R08: dffffc0000000000 R09: fffffbfff1d36176
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880556229f8 R14: ffff8880555b0368 R15: 0000000000000000
FS:  00007f5bf0b4a6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d607ff8 CR3: 000000002493c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 fat_mirror_bhs+0x3a8/0x4f0 fs/fat/fatent.c:398
 fat_alloc_clusters+0xd87/0x1190 fs/fat/fatent.c:543
 fat_add_cluster fs/fat/inode.c:108 [inline]
 __fat_get_block fs/fat/inode.c:155 [inline]
 fat_get_block+0x4c0/0xcf0 fs/fat/inode.c:190
 __block_write_begin_int+0x544/0x1a30 fs/buffer.c:1991
 __block_write_begin fs/buffer.c:2041 [inline]
 block_write_begin+0x98/0x1f0 fs/buffer.c:2102
 cont_write_begin+0x63f/0x880 fs/buffer.c:2456
 fat_write_begin+0x94/0x160 fs/fat/inode.c:235
 cont_expand_zero fs/buffer.c:2383 [inline]
 cont_write_begin+0x312/0x880 fs/buffer.c:2446
 fat_write_begin+0x94/0x160 fs/fat/inode.c:235
 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845
 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
 generic_file_write_iter+0xab/0x310 mm/filemap.c:4005
 do_iter_write+0x6e6/0xc40 fs/read_write.c:861
 vfs_writev fs/read_write.c:934 [inline]
 do_pwritev+0x216/0x360 fs/read_write.c:1031
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5befd85d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5bf0b4a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007f5beff75fa0 RCX: 00007f5befd85d29
RDX: 0000000000000001 RSI: 00000000200015c0 RDI: 000000000000000c
RBP: 00007f5befe01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000fffff R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5beff75fa0 R15: 00007ffe4275d318
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:mark_buffer_dirty_inode+0x2f1/0x300 fs/buffer.c:579
Code: e8 34 be e0 ff 48 8b 44 24 10 49 89 06 48 8b 7c 24 18 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d e9 04 9a bb 08 e8 6f 27 89 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 41 57 41 56 41 55
RSP: 0018:ffffc90004a3efc0 EFLAGS: 00010283
RAX: ffffffff82017491 RBX: ffff8880555b0588 RCX: 0000000000080000
RDX: ffffc900056d1000 RSI: 000000000002cce8 RDI: 000000000002cce9
RBP: 1ffff1100aab60b1 R08: dffffc0000000000 R09: fffffbfff1d36176
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880556229f8 R14: ffff8880555b0368 R15: 0000000000000000
FS:  00007f5bf0b4a6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7c00948178 CR3: 000000002493c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400