loop0: detected capacity change from 0 to 128
------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:991 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:991, CPU#0: syz.0.0/5322
Modules linked in:
CPU: 0 UID: 0 PID: 5322 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:mark_buffer_dirty+0x299/0x410 fs/buffer.c:991
Code: 4c 89 f7 e8 69 fa d7 ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 74 52 fb ff e8 af 58 66 ff eb 8c e8 a8 58 66 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 9a 58 66 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc9000ebbf438 EFLAGS: 00010287
RAX: ffffffff8261c6f8 RBX: ffff8880427fe7e0 RCX: 0000000000100000
RDX: ffffc9000f501000 RSI: 000000000001f27d RDI: 000000000001f27e
RBP: dffffc0000000001 R08: ffff8880427fe7e7 R09: 1ffff110084ffcfc
R10: dffffc0000000000 R11: ffffed10084ffcfd R12: dffffc0000000000
R13: 1ffff92001d77ebe R14: ffffc9000ebbf5f0 R15: ffff8880450ec788
FS:  00007f0e6a3d66c0(0000) GS:ffff88808c2bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e4bd909c0 CR3: 0000000012c66000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 mmb_mark_buffer_dirty+0x2c/0x1f0 fs/buffer.c:624
 fat12_ent_put+0x1b7/0x2f0 fs/fat/fatent.c:173
 fat_ent_write+0xb8/0x190 fs/fat/fatent.c:422
 fat_chain_add+0x409/0x8e0 fs/fat/misc.c:140
 fat_add_cluster fs/fat/inode.c:113 [inline]
 __fat_get_block fs/fat/inode.c:155 [inline]
 fat_get_block+0x768/0xae0 fs/fat/inode.c:190
 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030
 block_write_begin fs/buffer.c:2144 [inline]
 cont_write_begin+0x71b/0xac0 fs/buffer.c:2506
 fat_write_begin+0x7a/0x150 fs/fat/inode.c:230
 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374
 generic_file_write_iter+0xae/0x330 mm/filemap.c:4517
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e6959e159
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:00007f0e6a3d5fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0e69825fa0 RCX: 00007f0e6959e159
RDX: 00000000fffffceb RSI: 00002000000001c0 RDI: 0000000000000005
RBP: 00007f0e6963506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0e69826038 R14: 00007f0e69825fa0 R15: 00007ffd92d6a498
 </TASK>