audit: type=1804 audit(1569532175.747:196): pid=21294 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.5" name="/root/syzkaller-testdir022546976/syzkaller.DJRdxu/95/file0/file0" dev="loop5" ino=214 res=1 ------------[ cut here ]------------ kernel BUG at fs/buffer.c:605! invalid opcode: 0000 [#1] PREEMPT SMP KASAN kobject: 'loop5' (ffff8880a49eaa20): fill_kobj_path: path = '/devices/virtual/block/loop5' Modules linked in: CPU: 0 PID: 21294 Comm: syz-executor.5 Not tainted 4.14.146 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888056e74180 task.stack: ffff88808f658000 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:ffff88808f65f678 EFLAGS: 00010246 RAX: 0000000000040000 RBX: ffff88807f04e7e0 RCX: ffffc90007438000 RDX: 0000000000040000 RSI: ffffffff8199764a RDI: ffff8880959f6ef8 RBP: ffff88808f65f6b0 R08: ffff888056e74180 R09: 0000000000000004 R10: 0000000000000000 R11: ffff888056e74180 R12: ffff8880959f6d98 R13: 0000000000000000 R14: ffff8880a77b3420 R15: 0000000000003ecb FS: 00007f2bd24bb700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2bd2499db8 CR3: 000000005edb6000 CR4: 00000000001406f0 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:1084 SYSC_open fs/open.c:1102 [inline] SyS_open fs/open.c:1097 [inline] SYSC_creat fs/open.c:1142 [inline] SyS_creat+0x27/0x30 fs/open.c:1140 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459a29 RSP: 002b:00007f2bd24bac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000459a29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000080 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2bd24bb6d4 R13: 00000000004c0089 R14: 00000000004d2098 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 30 af 82 04 e9 13 fe ff ff e8 a6 6c c3 ff <0f> 0b 4c 89 ff e8 cc 1c ed ff e9 f8 fd ff ff e8 c2 1c ed ff e9 RIP: mark_buffer_dirty_inode fs/buffer.c:605 [inline] RSP: ffff88808f65f678 RIP: mark_buffer_dirty_inode+0x2ea/0x3e0 fs/buffer.c:596 RSP: ffff88808f65f678 ---[ end trace f7c779db4d0c1b09 ]---