loop0: detected capacity change from 0 to 8192
=======================================================
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
FAT-fs (loop0): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.
Buffer I/O error on dev loop0, logical block 2, lost sync page write
------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:991 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:991, CPU#0: syz.0.0/5323
Modules linked in:
CPU: 0 UID: 0 PID: 5323 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 9f 46 66 ff eb 8c e8 98 46 66 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 8a 46 66 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc9000dbf7270 EFLAGS: 00010283
RAX: ffffffff8261d748 RBX: ffff88801d06c000 RCX: 0000000000100000
RDX: ffffc9000e81a000 RSI: 000000000007693d RDI: 000000000007693e
RBP: dffffc0000000001 R08: ffff88801d06c007 R09: 1ffff11003a0d800
R10: dffffc0000000000 R11: ffffed1003a0d801 R12: ffffffff8c28b260
R13: ffff88803fd6c248 R14: dffffc0000000000 R15: ffff888051900788
FS:  00007fdd0cd106c0(0000) GS:ffff88808c2bb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005609d91a4e38 CR3: 00000000432b0000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 mmb_mark_buffer_dirty+0x2c/0x1f0 fs/buffer.c:624
 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
 cont_expand_zero fs/buffer.c:2434 [inline]
 cont_write_begin+0x2d6/0xac0 fs/buffer.c:2496
 fat_write_begin+0x7a/0x150 fs/fat/inode.c:230
 generic_cont_expand_simple+0x146/0x210 fs/buffer.c:2397
 fat_cont_expand+0x61/0x1f0 fs/fat/file.c:226
 fat_setattr+0x3e3/0xee0 fs/fat/file.c:550
 notify_change+0xbba/0xea0 fs/attr.c:556
 do_truncate+0x1c2/0x250 fs/open.c:68
 do_ftruncate+0x4d4/0x580 fs/open.c:194
 ksys_ftruncate fs/open.c:206 [inline]
 __do_sys_ftruncate fs/open.c:211 [inline]
 __se_sys_ftruncate fs/open.c:209 [inline]
 __x64_sys_ftruncate+0x8f/0xe0 fs/open.c:209
 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: 0033:0x7fdd0bd9e199
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:00007fdd0cd0ffe8 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007fdd0c025fa0 RCX: 00007fdd0bd9e199
RDX: 0000000000000000 RSI: 0000000002007ffb RDI: 0000000000000006
RBP: 00007fdd0be350b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdd0c026038 R14: 00007fdd0c025fa0 R15: 00007ffe5aacf8f8
 </TASK>