Fix: repeatedly dereference pom variables #2781
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Previously, if there was more than one layer of variable indirection in the pom property (propert A says it has the same value as property B, property B says it has the same value as property C), then Syft would only dereference one layer. Add a loop to dereference variables until either dereferencing fails, or until the variable is completely dereferenced back to a literal. Signed-off-by: Will Murphy <[email protected]>
| if value, ok := entries[propertyName]; ok { | ||
| return value | ||
| } | ||
| for propertyMatcher.MatchString(propertyCase) { |
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Note that this diff looks larger than it is, because the change in control flow intends the replace function one more tab, but the body of the replace function is not changed.
| propertyName := strings.TrimSpace(match[2 : len(match)-1]) // remove leading ${ and trailing } | ||
| entries := pomProperties(pom) | ||
| if value, ok := entries[propertyName]; ok { | ||
| return value |
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Instead of having a loop, adding a recursive call here to resolveProperty could also be a solution?
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That diff would potentially be a lot easier to read. Let me give that a shot. Thanks for the suggestion!
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Actually, in adding new tests for this implementation, I realized that there are two cases we need to make sure halt:
- Non-rooted deference, where following the path of repeated de-reference ends in a variable
- Cyclic dereference, where a variable refers to itself
Neither of these are well-formed pom.xml, we just need to defend against them hanging or overflowing the stack or something.
Signed-off-by: Will Murphy <[email protected]>
Signed-off-by: Will Murphy <[email protected]>
Signed-off-by: Will Murphy <[email protected]>
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@kzantow I changed to a recursive implementation and added more test cases to guard against degenerate pom files that have cyclic or unending variable definitions. Looking for a re-review when you have a moment. Thanks! |
Signed-off-by: Will Murphy <[email protected]>
* Fix: repeatedly dereference pom variables Previously, if there was more than one layer of variable indirection in the pom property (propert A says it has the same value as property B, property B says it has the same value as property C), then Syft would only dereference one layer. Add a loop to dereference variables until either dereferencing fails, or until the variable is completely dereferenced back to a literal. Signed-off-by: Will Murphy <[email protected]> * switch to recursive implementation Signed-off-by: Will Murphy <[email protected]> * add test cases for degenerate poms Signed-off-by: Will Murphy <[email protected]> * switch to recursive implementation Signed-off-by: Will Murphy <[email protected]> * remove redundant pieces of test cases Signed-off-by: Will Murphy <[email protected]> --------- Signed-off-by: Will Murphy <[email protected]>
Previously, if there was more than one layer of variable indirection in the pom property (propert A says it has the same value as property B, property B says it has the same value as property C), then Syft would only dereference one layer. Add a loop to dereference variables until either dereferencing fails, or until the variable is completely dereferenced back to a literal.
Fixes #2776
Manual testing on repro example from that issue: