justinrush
commented
3 years ago I'm seeing the same thing - oddly enough, it doesn't panic if pass something like []byte("[]wazza wazza woo"), but does panic if I pass slightly invalid json (missing a closing quote on level1.thing1):
{
"level1": {
"thing1: {
"somevalue": []
},
"thing2": {
"usefulthing": "bleh"
}
},
"level2": {
"widget1": {
"meh": {}
}
}
}Its panicing in parser.validateMapValue on this line: valueColumn := value.GetToken().Position.Column
It seems that parser.parseMapValue (called in parser.parseMappingValue) can return nil for value. Should a check be added to parser.parseMapValue to return an error if value is nil? It looks like parser.parseToken can return nil values for several conditions, but looking at other areas of the codebase (such as ast.Integer as is one of the stack traces above), the code assumes the value is not nil. Should parser.parseToken simply return an error if value is nil?
ernado
mx-psi
Found in go-fuzz https://github.com/dvyukov/go-fuzz
Bad inputs have panic. Some may have the same cause.
Output