audit: type=1804 audit(1563457340.797:140): pid=13785 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="ToMToU" comm="syz-executor.4" name="/root/syzkaller-testdir607157544/syzkaller.8OYudC/243/file0/file0" dev="loop4" ino=263 res=1 ------------[ cut here ]------------ kobject: 'loop4' (ffff8880a4a74a60): kobject_uevent_env kernel BUG at fs/buffer.c:605! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 13785 Comm: syz-executor.4 Not tainted 4.14.133 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88803f794500 task.stack: ffff88806bea0000 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:ffff88806bea7678 EFLAGS: 00010246 RAX: 0000000000040000 RBX: ffff888038db3930 RCX: ffffc9000c478000 RDX: 0000000000040000 RSI: ffffffff819921ca RDI: ffff88807e485ef8 RBP: ffff88806bea76b0 R08: ffff88803f794500 R09: 0000000000000004 R10: 0000000000000000 R11: ffff88803f794500 R12: ffff88807e485d98 kobject: 'loop4' (ffff8880a4a74a60): fill_kobj_path: path = '/devices/virtual/block/loop4' R13: 0000000000000000 R14: ffff8880a77d24e0 R15: 0000000000003376 FS: 00007f083c9ad700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f083c98bdb8 CR3: 000000008ff6a000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fat16_ent_put+0xc5/0x100 /fs/fat/fatent.c:181 fat_free_clusters+0x369/0x810 /fs/fat/fatent.c:593 fat_free /fs/fat/file.c:351 [inline] fat_truncate_blocks+0x693/0xae0 /fs/fat/file.c:369 fat_setattr+0x6c1/0xae0 /fs/fat/file.c:513 notify_change+0x8d1/0xd10 /fs/attr.c:313 do_truncate+0x124/0x1c0 /fs/open.c:63 handle_truncate /fs/namei.c:3009 [inline] do_last /fs/namei.c:3434 [inline] path_openat+0x2786/0x3f70 /fs/namei.c:3566 do_filp_open+0x18e/0x250 /fs/namei.c:3600 do_sys_open+0x2c5/0x430 /fs/open.c:1065 SYSC_open /fs/open.c:1083 [inline] SyS_open /fs/open.c:1078 [inline] SYSC_creat /fs/open.c:1123 [inline] SyS_creat+0x27/0x30 /fs/open.c:1121 do_syscall_64+0x1e8/0x640 /arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459819 RSP: 002b:00007f083c9acc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000459819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f083c9ad6d4 R13: 00000000004bfe84 R14: 00000000004d1ae0 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 f0 8b 81 04 e9 13 fe ff ff e8 26 85 c3 ff <0f> 0b 4c 89 ff e8 dc 26 ed ff e9 f8 fd ff ff e8 d2 26 ed ff e9 RIP: mark_buffer_dirty_inode /fs/buffer.c:605 [inline] RSP: ffff88806bea7678 RIP: mark_buffer_dirty_inode+0x2ea/0x3e0 /fs/buffer.c:596 RSP: ffff88806bea7678 ---[ end trace fa4cb778ceadbf86 ]---