------------[ cut here ]------------ kernel BUG at fs/buffer.c:555! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 27184 Comm: syz-executor.0 Not tainted 5.4.13-syzkaller-00760-gb0b02162a4b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mark_buffer_dirty_inode+0x2fb/0x300 fs/buffer.c:555 Code: ef e8 e9 77 ed ff 48 8b 45 b8 49 89 45 00 48 89 df e8 19 28 03 02 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 55 75 bf ff <0f> 0b 0f 1f 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 49 89 fe 49 RSP: 0018:ffff8881d0f36fe8 EFLAGS: 00010287 RAX: ffffffff81834b6b RBX: 1ffff11032637677 RCX: 0000000000040000 RDX: ffffc90001f7b000 RSI: 000000000001c205 RDI: 000000000001c206 RBP: ffff8881d0f37038 R08: ffffffff81647cb3 R09: fffff94000d9a409 R10: fffff94000d9a409 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8881931bb320 R14: ffff88818ecf8e70 R15: ffff8881931bb3b8 FS: 00007f42c1ba2700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001e57978 CR3: 00000001d7af7002 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fat_mirror_bhs+0x31e/0x470 fs/fat/fatent.c:396 fat_alloc_clusters+0x10e9/0x13e0 fs/fat/fatent.c:541 fat_add_cluster fs/fat/inode.c:107 [inline] __fat_get_block fs/fat/inode.c:154 [inline] fat_get_block+0x39c/0xac0 fs/fat/inode.c:189 __block_write_begin_int+0x68b/0x1770 fs/buffer.c:1969 __block_write_begin fs/buffer.c:2019 [inline] block_write_begin+0x5e/0x150 fs/buffer.c:2078 cont_write_begin+0x603/0x8a0 fs/buffer.c:2427 fat_write_begin+0xa6/0x180 fs/fat/inode.c:235 pagecache_write_begin+0x98/0xb0 mm/filemap.c:3128 cont_expand_zero fs/buffer.c:2354 [inline] cont_write_begin+0x217/0x8a0 fs/buffer.c:2417 fat_write_begin+0xa6/0x180 fs/fat/inode.c:235 pagecache_write_begin+0x98/0xb0 mm/filemap.c:3128 generic_cont_expand_simple+0xd8/0x1b0 fs/buffer.c:2318 fat_cont_expand+0x6b/0x1f0 fs/fat/file.c:233 fat_setattr+0x305/0xd50 fs/fat/file.c:512 notify_change2+0xaf3/0xf20 fs/attr.c:339 do_truncate2 fs/open.c:64 [inline] do_sys_ftruncate+0x5c3/0x740 fs/open.c:204 __do_sys_ftruncate fs/open.c:214 [inline] __se_sys_ftruncate fs/open.c:212 [inline] __x64_sys_ftruncate+0x60/0x70 fs/open.c:212 do_syscall_64+0xc0/0x100 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45b349 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f42c1ba1c78 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007f42c1ba26d4 RCX: 000000000045b349 RDX: 0000000000000000 RSI: 0000000000200004 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000000e3 R14: 00000000004c21a7 R15: 000000000075bf2c Modules linked in: ---[ end trace f363f60a3fd4c870 ]--- RIP: 0010:mark_buffer_dirty_inode+0x2fb/0x300 fs/buffer.c:555 Code: ef e8 e9 77 ed ff 48 8b 45 b8 49 89 45 00 48 89 df e8 19 28 03 02 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 55 75 bf ff <0f> 0b 0f 1f 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 49 89 fe 49 RSP: 0018:ffff8881d0f36fe8 EFLAGS: 00010287 RAX: ffffffff81834b6b RBX: 1ffff11032637677 RCX: 0000000000040000 RDX: ffffc90001f7b000 RSI: 000000000001c205 RDI: 000000000001c206 RBP: ffff8881d0f37038 R08: ffffffff81647cb3 R09: fffff94000d9a409 R10: fffff94000d9a409 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8881931bb320 R14: ffff88818ecf8e70 R15: ffff8881931bb3b8 FS: 00007f42c1ba2700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42ab6d000 CR3: 00000001d7af7005 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400