Commit 644a89e080bced793295f61f18aac8cfad6bece2
2022-08-31T22:11:25
[CVE-2022-40304] Fix dict corruption caused by entity reference cycles When an entity reference cycle is detected, the entity content is cleared by setting its first byte to zero. But the entity content might be allocated from a dict. In this case, the dict entry becomes corrupted leading to all kinds of logic errors, including memory errors like double-frees. Stop storing entity content, orig, ExternalID and SystemID in a dict. These values are unlikely to occur multiple times in a document, so they shouldn't have been stored in a dict in the first place. Thanks to Ned Williamson and Nathan Wachholz working with Google Project Zero for the report!