IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
Entities which reference out-of-scope namespace have always been broken.
xmlParseBalancedChunkMemoryInternal tried to reuse the namespaces
currently in scope but these namespaces were ignored by the SAX handler.
Besides, there could be different namespaces in scope when expanding the
entity again. For example:
<!DOCTYPE doc [
<!ENTITY ent "<ns:elem/>">
]>
<doc>
<decl1 xmlns:ns="urn:ns1">
&ent;
</decl1>
<decl2 xmlns:ns="urn:ns2">
&ent;
</decl2>
</doc>
Add some comments outlining possible solutions to this problem.
For now, we stop copying namespaces to the temporary parser context
in xmlParseBalancedChunkMemoryInternal. This has never really worked
and the recent changes contained a partial fix which uncovered other
problems like a use-after-free with the XML Reader interface, found
by OSS-Fuzz.
To check whether an entity was already parsed, the code previously
tested whether "checked" was non-zero or "children" was non-null. The
"children" check could be unreliable because an empty entity also
results in an empty (NULL) node list. Use a separate flag to make this
check more reliable.
Remove explicit integer casts as final operation
- in assignments
- when passing arguments
- when returning values
Remove casts
- to the same type
- from certain range-bound values
The main motivation is that these explicit casts don't change the result
of operations and only render UBSan's implicit-conversion checks
useless. Removing these casts allows UBSan to detect cases where
truncation or sign-changes occur unexpectedly.
Document some explicit casts as truncating and add a few missing ones.
Private functions were previously declared
- in header files in the root directory
- in public headers guarded with IN_LIBXML
- in libxml.h
- redundantly in source files that used them.
Consolidate all private header files in include/private.
This is a follow-up to commit 6c283d83.
* buf.c:
(xmlBufGrowInternal):
- Call xmlBufMemoryError() when the buffer size would overflow.
- Account for NUL terminator byte when using XML_MAX_TEXT_LENGTH.
- Do not include NUL terminator byte when returning length.
(xmlBufAdd):
- Call xmlBufMemoryError() when the buffer size would overflow.
* tree.c:
(xmlBufferGrow):
- Call xmlTreeErrMemory() when the buffer size would overflow.
- Do not include NUL terminator byte when returning length.
(xmlBufferResize):
- Update error message in xmlTreeErrMemory() to be consistent
with other similar messages.
(xmlBufferAdd):
- Call xmlTreeErrMemory() when the buffer size would overflow.
(xmlBufferAddHead):
- Add overflow checks similar to those in xmlBufferAdd().
* buf.c:
(xmlBufAddLen):
- Change check for remaining space to account for the NUL
terminator. When adding a length exactly equal to the number
of unused bytes, a NUL terminator was not written.
(xmlBufResize):
- Set `buf->use` and NUL terminator when allocating a new
buffer.
* tree.c:
(xmlBufferResize):
- Set `buf->use` and NUL terminator when allocating a new
buffer.
(xmlBufferAddHead):
- Set NUL terminator before returning early when shifting
contents.
When changing `doc` on an xmlNodePtr or xmlAttrPtr, certain
fields must either be a free-standing string, or they must be
owned by `doc->dict`.
The code to make this change was simply missing, so the crash
happened when an xmlAttrPtr was being torn down after `doc`
changed from non-NULL to NULL, but the `name` field was not
copied. This is scenario 1 below.
The xmlNodePtr->name and xmlNodePtr->content fields are also
fixed at the same time. Note that xmlNodePtr->content is never
added to the dictionary, so NULL is used instead of `newDict` to
force a free-standing copy.
This change covers all cases of dictionary changes:
1. Owned by old dictionary -> NULL new dictionary
- Create free-standing copy of string.
2. Owned by old dictionary -> Non-NULL new dictionary
- Get string from new dictionary pool.
3. Not owned by old dictionary -> Non-NULL new dictionary
- No action necessary (already a free-standing string).
4. Not owned by old dictionary -> NULL new dictionary
- No action necessary (already a free-standing string).
* tree.c:
(_copyStringForNewDictIfNeeded): Add.
(xmlSetTreeDoc):
- Update xmlNodePtr->name, xmlNodePtr->content and
xmlAttrPtr->name when changing the document, if needed.
Found by OSS-Fuzz Issue 45132.
In several places, the code handling string buffers didn't check for
integer overflow or used wrong types for buffer sizes. This could
result in out-of-bounds writes or other memory errors when working on
large, multi-gigabyte buffers.
Thanks to Felix Wilhelm for the report.
Commit 7618a3b1 didn't account for coalesced text nodes.
I think it would be better if xmlStaticCopyNode didn't try to coalesce
text nodes at all. This code path can only be triggered if some other
code doesn't coalesce text nodes properly. In this case, OSS-Fuzz found
such behavior in xinclude.c.
In most places, we really need the double-it scheme to avoid quadratic
behavior. The hybrid scheme still can cause many reallocations and the
bounded scheme doesn't seem to provide meaningful protection in
xmlreader.c.
This code has been broken and deprecated since version 2.6.0, released
in 2003. Because of a bug in commit 961b535c, DOCBparser.c was never
compiled since 2012. I couldn't find a Debian package using any of its
symbols, so it seems safe to remove this module.
The children member of entity reference nodes points to the entity
declaration and must never be followed when traversing a tree. In
the worst case, this could lead to an infinite loop.
It's somewhat unclear how moving entity references to other documents
should work exactly. For now we simply set the children pointer to NULL
to avoid a reference to the original document.
Fixes#42.
Client code should never add document nodes as children of other nodes,
but even our own XPointer code has a bug that can produce such trees.
Make sure to really free nested documents. Also see commits 0815302d
and 0762c9b6.
Should fix#269.
