panic: runtime error: index out of range

[YoungWing]

panic: runtime error: index out of range

goroutine 411988086 [running]:
panic(0xa92dc0, 0xc42000a0e0)
/usr/local/go/src/runtime/panic.go:500 +0x1a1
github.com/oschwald/maxminddb-golang.(*decoder).decodeCtrlData(0xc4202e6020, 0x79d7b07, 0x0, 0x7f267c0650dc, 0x4)
/Users/yangrong/go/src/github.com/oschwald/maxminddb-golang/decoder.go:48 +0xbe
github.com/oschwald/maxminddb-golang.(*decoder).decode(0xc4202e6020, 0x79d7b07, 0xaf1660, 0xc42a377b80, 0x199, 0x199, 0x199, 0xaf1660)
/Users/yangrong/go/src/github.com/oschwald/maxminddb-golang/decoder.go:37 +0x39
github.com/oschwald/maxminddb-golang.(*decoder).unmarshalPointer(0xc4202e6020, 0x1b, 0x304a, 0xaf1660, 0xc42a377b80, 0x199, 0x199, 0x738732, 0xc4202e6020)
/Users/yangrong/go/src/github.com/oschwald/maxminddb-golang/decoder.go:277 +0x86
github.com/oschwald/maxminddb-golang.(*decoder).decodeFromType(0xc4202e6020, 0x1, 0x1b, 0x304a, 0xa41de0, 0xc42a377b80, 0x16, 0x7c5c4, 0x0, 0xa41de0)
/Users/yangrong/go/src/github.com/oschwald/maxminddb-golang/decoder.go:103 +0x2a8
github.com/oschwald/maxminddb-golang.(*decoder).decode(0xc4202e6020, 0x3049, 0xa41de0, 0xc42a377b80, 0x16, 0xc4202e6000, 0xc420d88fec, 0x4)
/Users/yangrong/go/src/github.com/oschwald/maxminddb-golang/decoder.go:43 +0xa0
github.com/oschwald/maxminddb-golang.(*Reader).Decode(0xc4202e6000, 0x3049, 0xa41de0, 0xc42a377b80, 0x0, 0xc4204737b0)
/Users/yangrong/go/src/github.com/oschwald/maxminddb-golang/reader.go:152 +0x13a
github.com/oschwald/maxminddb-golang.(*Reader).retrieveData(0xc4202e6000, 0x7c5c4, 0xa41de0, 0xc42a377b80, 0x7c5c4, 0x0)
/Users/yangrong/go/src/github.com/oschwald/maxminddb-golang/reader.go:236 +0x74
github.com/oschwald/maxminddb-golang.(*Reader).Lookup(0xc4202e6000, 0xc420d88fe0, 0x10, 0x10, 0xa41de0, 0xc42a377b80, 0xc, 0xc420d88fe0)
/Users/yangrong/go/src/github.com/oschwald/maxminddb-golang/reader.go:114 +0xa6
github.com/oschwald/geoip2-golang.(*Reader).Country(0xc42015a5e0, 0xc420d88fe0, 0x10, 0x10, 0x10, 0xc420d88fd0, 0xd)
/Users/yangrong/go/src/github.com/oschwald/geoip2-golang/reader.go:235 +0x1b7

[oschwald]

How do I reproduce this?

[oschwald]

Although it does not excuse the panic, I suspect your database is corrupt. It would be useful to get a copy of the database as well as the lookup that causes this so that I can confirm any fix. I am, however, running go-fuzz against the library in an attempt to find similar issues.

[oschwald]

I suspect this panic on a corrupt database is fixed in greg/fuzz-fixes.

[oschwald]

This panic should now no longer be possible. An error would be returned instead.