OVAL/XCCDF/DS/source: fix memory-corruption bugs on malformed input#2363
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OVAL/XCCDF/DS/source: fix memory-corruption bugs on malformed input#2363edznux-dd wants to merge 1 commit into
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- OVAL oval_set.c: a <set> mixing a nested <set> (aggregate) with
object_reference/filter children (collective) wrote into the wrong union
member, so oval_setobject_free() later freed a model-owned object
(use-after-free / double free). Reject children that don't match the
established set type.
- XCCDF resolve.c: <warning> entries were resolved through
xccdf_resolve_textlist(), which reads each item as oscap_text -- but a
xccdf_warning is smaller, so this read out of bounds (heap-buffer-overflow).
Added a dedicated xccdf_resolve_warninglist() operating on warning->text.
- DS sds.c: component_id aliased the xlink_href buffer that was freed too
early (use-after-free); keep it alive until last use. Also cap catalog
component-ref recursion (cyclic catalog -> OOM); this recursion-DoS fix is
bundled here because it is interleaved with the UAF fix in the same function.
Also a NULL id guard in lookup_component_in_collection.
- source/schematron.c: OSCAP_SCHEMATRON_TABLE lacked the {0,NULL,NULL}
sentinel its lookup loop relies on -> global-buffer-overflow; added it.
Plus NULL guards for missing href/uri, empty <catalog>, and NULL XPath eval.
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(see #2361 for more context)
This is the 3rd PR of the series (out of 4). This one focuses on UaF, double free and heap buffer overflow found with the fuzzer setup (under address sanitizer for ease of discovery)
Open question:
I've set
#define DS_SDS_MAX_COMPONENT_REF_DEPTHto an arbitrary limit of30, but I'm not familiar enough withopenscapexpectations here to see if this could/should be lowered. 30 was a safe, but conservative value (I don't see a real scenario where it would be > 5, but I might be completely miss guided here)For more context: