tree 3075d9d178fd168654cdbe93017b5dd59b6afbb0
parent 4d1379a8d47c8d441d4d3076fe712d0815cf1786
author Hui Yingst <nigi@chromium.org> 1687382509 +0000
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> 1687382509 +0000

Fix stack-overflow in CheckForSharedFormInternal()

CheckForSharedFormInternal() is called recursively to traverse the
nodes in a meta data tree. If the meta data contains corrupted data
and never closes XML tags correctly, it could trigger stack-overflow
in this function.

This CL adds `kMaxMetaDataDepth` as the arbitrary maximum meta data
tree depth to prevent too many recursive calls of
CheckForSharedFormInternal() and adds a unit test for it. Also
renames `pElement` to `xml_element` to fit the c++ style guide better.

Bug: chromium:1012377
Change-Id: Iaad7a07c6dc17d37130fdfd1e02441ba50b2066e
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/108910
Commit-Queue: Nigi <nigi@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>