Crashed by invalid input

Found in fuzz test with go-fuzz

input: "\ue031"

package main

import "github.com/mattn/anko/parser"

func main() {
    _, err := parser.ParseSrc("\ue031")
    if err != nil {
        panic(err)
    }
}

$ go run ./main.go
signal: killed

fuzz code

package parser

import "github.com/mattn/anko/parser"

func Fuzz(data []byte) int {
    _, err := parser.ParseSrc(string(data))
    if err != nil {
        return 0
    }
    return 1
}

crash log

program hanged (timeout 10 seconds)

SIGABRT: abort
PC=0x45e721 m=0 sigcode=0

goroutine 0 [idle]:
runtime.futex(0x5efec8, 0x80, 0x0, 0x0, 0x7f5800000000, 0x0, 0xc000118000, 0x7ffc00000001, 0x7ffcaf2e6e68, 0x40a28f, ...)
    runtime/sys_linux_amd64.s:567 +0x21
runtime.futexsleep(0x5efec8, 0x7f5800000000, 0xffffffffffffffff)
    runtime/os_linux.go:45 +0x46
runtime.notesleep(0x5efec8)
    runtime/lock_futex.go:151 +0x9f
runtime.stopm()
    runtime/proc.go:1834 +0xc0
runtime.exitsyscall0(0xc000000180)
    runtime/proc.go:3268 +0x111
runtime.mcall(0x0)
    runtime/asm_amd64.s:318 +0x5b

goroutine 1 [runnable]:
github.com/mattn/anko/parser.yylex1(0x538220, 0xc00037d8b0, 0xc000164500, 0xe031, 0x33)
    /home/heijo/go/pkg/mod/github.com/mattn/anko@v0.1.8/parser/parser.go:1042 +0x466
github.com/mattn/anko/parser.(*yyParserImpl).Parse(0xc000164500, 0x538220, 0xc00037d8b0, 0x0)
    /home/heijo/go/pkg/mod/github.com/mattn/anko@v0.1.8/parser/parser.go:1129 +0x161db
github.com/mattn/anko/parser.yyParse(...)
    /home/heijo/go/pkg/mod/github.com/mattn/anko@v0.1.8/parser/parser.go:1078
github.com/mattn/anko/parser.Parse(0xc000101650, 0xc000101650, 0x3, 0xc0003b38c8, 0x1)
    /home/heijo/go/pkg/mod/github.com/mattn/anko@v0.1.8/parser/lexer.go:591 +0xef
github.com/mattn/anko/parser.ParseSrc(0xc000420e78, 0x3, 0x3, 0x3, 0xc000420e78, 0x3)
    /home/heijo/go/pkg/mod/github.com/mattn/anko@v0.1.8/parser/lexer.go:612 +0xb9
github.com/johejo/go-fuzz-contrib/github.com/mattn/anko/parser.Fuzz(0x7f583a827000, 0x3, 0x3, 0x3)
    /home/heijo/ghq/github.com/johejo/go-fuzz-contrib/github.com/mattn/anko/parser/fuzz.go:6 +0x7d
go-fuzz-dep.Main(0xc000420f70, 0x1, 0x1)
    go-fuzz-dep/main.go:36 +0x1ad
main.main()
    github.com/johejo/go-fuzz-contrib/github.com/mattn/anko/parser/go.fuzz.main/main.go:15 +0x52

rax    0xca
rbx    0x5efd80
rcx    0x45e723
rdx    0x0
rdi    0x5efec8
rsi    0x80
rbp    0x7ffcaf2e6e30
rsp    0x7ffcaf2e6de8
r8     0x0
r9     0x0
r10    0x0
r11    0x286
r12    0x5debc0
r13    0x5ddda0
r14    0x5d85c0
r15    0x4
rip    0x45e721
rflags 0x286
cs     0x33
fs     0x0
gs     0x0
exit status 2

mattn / anko

Crashed by invalid input #341