syzbot

 do_splice_direct+0x164/0x210 fs/splice.c:1061
------------[ cut here ]------------
WARNING: CPU: 0 PID: 28311 at fs/super.c:1163 kill_block_super+0xbe/0xe0 fs/super.c:1163
Kernel panic - not syncing: panic_on_warn set ...

 do_sendfile+0x469/0xaf0 fs/read_write.c:1441
 SYSC_sendfile64 fs/read_write.c:1496 [inline]
 SyS_sendfile64+0x9b/0x110 fs/read_write.c:1488
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cb29
RSP: 002b:00007f701ff28c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000004fd880 RCX: 000000000045cb29
RDX: 0000000020000040 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000005
R13: 0000000000000905 R14: 00000000004cbe3c R15: 00007f701ff296d4
CPU: 0 PID: 28311 Comm: syz-executor.3 Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
 __warn.cold+0x2f/0x30 kernel/panic.c:547
 report_bug+0x20a/0x248 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:kill_block_super+0xbe/0xe0 fs/super.c:1163
RSP: 0018:ffff888056ca7a98 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc9000a51d000
RDX: 0000000000040000 RSI: ffffffff818c077e RDI: ffff8880a6f064e8
RBP: ffff8880627ca100 R08: 0000000000000001 R09: 0000000000000001
R10: ffff88805c100e98 R11: ffff88805c1005c0 R12: ffff8880a6f06140
R13: ffff8880627ca240 R14: dffffc0000000000 R15: ffffffff87b534c0
 gfs2_kill_sb+0x144/0x1a0 fs/gfs2/ops_fstype.c:1384
 deactivate_locked_super+0x6c/0xd0 fs/super.c:319
 sget_userns+0x9df/0xc30 fs/super.c:537
 sget+0xd1/0x110 fs/super.c:572
 gfs2_mount+0x10f/0x4f3 fs/gfs2/ops_fstype.c:1278
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x3c9/0x25e0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45f57a
RSP: 002b:00007f68cf3b6a68 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000050a380 RCX: 000000000045f57a
RDX: 00007f68cf3b6ae0 RSI: 00000000200000c0 RDI: 00007f68cf3b6b00
RBP: 000000000078bf00 R08: 00007f68cf3b6b40 R09: 00007f68cf3b6ae0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000003
R13: 0000000000000c31 R14: 00000000004ce7ee R15: 00007f68cf3b76d4
Kernel Offset: disabled
Rebooting in 86400 seconds..