------------[ cut here ]------------ kernel BUG at fs/buffer.c:605! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 11490 Comm: syz-executor.0 Not tainted 4.14.149 #0 kobject: 'loop4' (ffff8880a4b37220): kobject_uevent_env Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888058a066c0 task.stack: ffff88805e870000 RIP: 0010:mark_buffer_dirty_inode fs/buffer.c:605 [inline] RIP: 0010:mark_buffer_dirty_inode+0x2ea/0x3e0 fs/buffer.c:596 RSP: 0018:ffff88805e8773e8 EFLAGS: 00010246 RAX: 0000000000040000 RBX: ffff88807fac7c78 RCX: ffffc9000823f000 RDX: 0000000000040000 RSI: ffffffff8199885a RDI: ffff888051c61ef8 RBP: ffff88805e877420 R08: ffff888058a066c0 R09: 0000000000000004 R10: 0000000000000000 R11: ffff888058a066c0 R12: ffff888051c61d98 R13: 0000000000000000 R14: ffff8880881725e0 R15: ffff88805e8776a8 FS: 00007fc5dd331700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kobject: 'loop4' (ffff8880a4b37220): fill_kobj_path: path = '/devices/virtual/block/loop4' CR2: 0000000000000000 CR3: 0000000053499000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fat12_ent_put+0x176/0x370 fs/fat/fatent.c:170 fat_alloc_clusters+0x5a4/0xdb0 fs/fat/fatent.c:502 kobject: 'loop4' (ffff8880a4b37220): kobject_uevent_env fat_add_cluster+0x60/0xc0 fs/fat/inode.c:100 kobject: 'loop4' (ffff8880a4b37220): fill_kobj_path: path = '/devices/virtual/block/loop4' __fat_get_block fs/fat/inode.c:147 [inline] fat_get_block+0x2d4/0x7e0 fs/fat/inode.c:176 __block_write_begin_int+0x396/0x1100 fs/buffer.c:2027 BFS-fs: bfs_fill_super(): No BFS filesystem on loop4 (magic=00000000) __block_write_begin fs/buffer.c:2077 [inline] block_write_begin+0x5f/0x190 fs/buffer.c:2136 cont_write_begin+0x430/0x770 fs/buffer.c:2486 fat_write_begin+0x8d/0x120 fs/fat/inode.c:222 generic_perform_write+0x1f8/0x480 mm/filemap.c:3046 __generic_file_write_iter+0x239/0x5b0 mm/filemap.c:3171 generic_file_write_iter+0x303/0x660 mm/filemap.c:3199 call_write_iter include/linux/fs.h:1777 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x4a7/0x6b0 fs/read_write.c:482 vfs_write+0x198/0x500 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xfd/0x230 fs/read_write.c:582 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459a59 RSP: 002b:00007fc5dd330c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a59 RDX: 000000000076656f RSI: 00000000200009c0 RDI: 0000000000000008 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc5dd3316d4 R13: 00000000004c9eb5 R14: 00000000004e1ad8 R15: 00000000ffffffff Code: fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 4d 4c 89 63 58 4c 89 ef e8 70 df 82 04 e9 13 fe ff ff e8 a6 6b c3 ff <0f> 0b 4c 89 ff e8 1c 1d ed ff e9 f8 fd ff ff e8 12 1d ed ff e9 RIP: mark_buffer_dirty_inode fs/buffer.c:605 [inline] RSP: ffff88805e8773e8 RIP: mark_buffer_dirty_inode+0x2ea/0x3e0 fs/buffer.c:596 RSP: ffff88805e8773e8 ---[ end trace d71c7ecf4663264c ]---