list is tainted by calling list.append(TAINT) #181
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KevinHock
approved these changes
Nov 1, 2018
| @@ -578,6 +580,23 @@ def visit_Call(self, node): | |||
| else: | |||
| raise Exception('Definition was neither FunctionDef or ' + | |||
| 'ClassDef, cannot add the function ') | |||
| elif ( | |||
Taint is propagated by: ``` list += [TAINT] list = list + TAINT ``` but with lists we often use a function to mutate the list: ``` list = [] list.append(TAINT) list.insert(0, TAINT) list.extend(TAINT) ``` Previously this didn't taint `list` so we had FALSE NEGATIVES. Now `list.append(TAINT)` is treated like augmented assignment, so list will be tainted. `list += list.append(TAINT)` Of course this wouldn't work as real code since `append` returns `None` but it is how you can think about this function which mutates `list`. The same goes for `set.add()`, `list.extend()`, `list.insert()`, `dict.update()`, although we aren't actually doing type checking, just looking at the name of the method.
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Taint is propagated by:
but with lists we often use a function to mutate the list:
Previously this didn't taint
listso we had FALSE NEGATIVES.Now
list.append(TAINT)is treated like augmented assignment, so listwill be tainted.
list += list.append(TAINT)Of course this wouldn't work as real code since
appendreturnsNonebut it is how you can think about this function which mutates
list.The same goes for
set.add(),list.extend(),list.insert(),dict.update(), although we aren't actually doing type checking, justlooking at the name of the method.