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mirror of https://gitlab.gnome.org/GNOME/libxml2.git synced 2025-02-06 05:57:39 +03:00

546 Commits

Author SHA1 Message Date
Nick Wellnhofer
f61b8a6233 parser: Fix DTD parser progress checks
This is another attempt at fixing parser progress checks. Instead of
relying on in->consumed, which could overflow, change some DTD parser
functions to make guaranteed progress on certain byte sequences.
2022-11-20 21:16:03 +01:00
Nick Wellnhofer
b456e3bb42 xinclude: Always allow XPtr expressions in external documents 2022-10-31 16:49:36 +01:00
Nick Wellnhofer
eef0a7395c xinclude: Implement "streaming" mode
When using xmlreader, XPointer expressions in XIncludes simply cannot
work. Expressions can reference nodes which weren't parsed yet or which
were already deleted.

After fixing nested XIncludes, we reference includes which were parsed
previously. When streaming, these nodes could have been deleted, leading
to use-after-free errors.

Disallow XPointer expressions and truncate the include table in
streaming mode.
2022-10-30 14:12:55 +01:00
Nick Wellnhofer
20e2fb4c1c xinclude: Avoid creation of subcontexts
Don't create subcontext in xmlXIncludeRecurseDoc. Save and restore 'doc'
and 'incTab' instead.

Make xmlXIncludeLoadFallback call xmlXIncludeCopyNode which seems safer
than xmlXIncludeDoProcess since the latter may modify the document.
This should also be more performant since we need to copy the whole
fallback subtree anyway. Also make sure to avoid replacements in
fallback elements in xmlXIncludeDoProcess.
2022-10-25 19:34:38 +02:00
Nick Wellnhofer
d2ed1e4f99 xinclude: Limit recursion depth
This avoids call stack overflows.
2022-10-23 18:52:56 +02:00
Nick Wellnhofer
34496f26db xinclude: Test for inclusion loops 2022-10-23 14:27:05 +02:00
Nick Wellnhofer
bc267cb9bc xinclude: Expand includes in xmlXIncludeCopyNode
This should make nested includes work reliably.

Fixes #424.
2022-10-23 14:27:05 +02:00
Nick Wellnhofer
ea7c9fb5dd xinclude: Don't create result doc for test with errors 2022-10-23 14:27:05 +02:00
Nick Wellnhofer
c99cde3f21 xinclude: Also test error messages
The reader interface with XIncludes is somewhat broken and can generate
different error messages. Start to move tests which are sketchy with
reader to a separate directory.
2022-10-23 14:26:59 +02:00
Nick Wellnhofer
938105b572 Revert "xinclude: Fix regression with nested includes"
This reverts commit 7f04e297318b1b908cec20711f74f75625afed7f which
caused memory errors.

See #424.
2022-10-21 15:56:12 +02:00
Nick Wellnhofer
7f04e29731 xinclude: Fix regression with nested includes
This reverts commits 74dcc10b and 87d20b55.

Fixes #424.
2022-10-18 19:17:45 +02:00
Nick Wellnhofer
1d4f5d24ac schemas: Fix null-pointer-deref in xmlSchemaCheckCOSSTDerivedOK
Found by OSS-Fuzz.
2022-09-13 16:56:59 +02:00
Nick Wellnhofer
c714979293 Fix --with-valid --without-regexps build
This build config resulted in segfaults in 'runtest'  because a special
xmlElementContentPtr showed up in a few places. I'm not sure if this is
the right fix.

An error message was changed to conform to the --with-regexps build.

There are still a few missing validity errors, so the tests don't pass.
2022-09-02 18:33:35 +02:00
Nick Wellnhofer
e986d09cf5 Skip incorrectly opened HTML comments
Commit 4fd69f3e fixed handling of '<' characters not followed by an
ASCII letter. But a '<!' sequence followed by invalid characters should
be treated as bogus comment and skipped.

Fixes #380.
2022-08-02 14:38:09 +02:00
Nick Wellnhofer
145170125a Fix parsing of subtracted regex character classes
Fixes #370.
2022-04-23 19:22:42 +02:00
Nick Wellnhofer
4612ce3031 Implement xpath1() XPointer scheme
See https://www.w3.org/2005/04/xpointer-schemes/
2022-04-21 04:26:52 +02:00
Nick Wellnhofer
41afa89fc9 Fix short-lived regression in xmlStaticCopyNode
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.
2022-04-10 14:17:31 +02:00
Nick Wellnhofer
4de7f2acfe Remove unused result files 2022-04-04 04:28:15 +02:00
Nick Wellnhofer
f1c32b4c78 Allow missing result files in runtest
Treat missing files as empty.
2022-04-04 04:28:15 +02:00
Nick Wellnhofer
95c7f315ab Move SVG tests to runtest.c
Also update the test results for the first time since 2000.
2022-04-04 04:18:07 +02:00
Nick Wellnhofer
48b03c8479 Remove major parts of old test suite
Remove all the parts of the old test suite which are covered by
runtest.c for quite some time.

The following test programs are removed:

- testC14N
- testHTML
- testReader
- testRelax
- testSAX
- testSchemas
- testURI
- testXPath

This also removes a few results of unimportant tests only run by the old
test suite.
2022-04-04 04:14:55 +02:00
Nick Wellnhofer
57b81c208c Normalize XPath strings in-place
Simplify the code and fix a potential memory leak.

Fixes #343.
2022-03-05 18:22:51 +01:00
Nick Wellnhofer
bc06a522c1 Fix recursion check in xinclude.c
Compare the included URL with the document's URL to detect local
inclusions.

Fixes #348.
2022-03-02 20:44:41 +01:00
Mike Dalessio
d7b287b94c htmlParseComment: handle abruptly-closed comments
See guidance provided on abrutply-closed comments here:

https://html.spec.whatwg.org/multipage/parsing.html#parse-error-abrupt-closing-of-empty-comment
2022-03-02 14:42:47 +00:00
Mike Dalessio
24cdc89006 test coverage for abruptly-closed comments
These establish baseline behavior so that the subsequent commit is
clear about the behavior it will modify.
2022-03-02 14:42:47 +00:00
Nick Wellnhofer
ea6e8f998d Fix certain combinations of regex range quantifiers
Fix regex transitions that have both min/max and a counter. In this
case, we want to save the regex state before incrementing the counter.

Fixes #301 and the issue reported here:

https://mail.gnome.org/archives/xml/2016-April/msg00017.html
2022-02-28 16:56:02 +01:00
Nick Wellnhofer
382fb056b5 Fix range quantifier on subregex
Make sure to add counted exit transitions before other counter
transitions. Otherwise, we won't backtrack correctly.

Fixes #65.
2022-02-28 16:56:02 +01:00
Nick Wellnhofer
ce0871e15c Only warn on invalid redeclarations of predefined entities
Downgrade the error message to a warning since the error was ignored,
anyway. Also print the name of redeclared entity. For a proper fix that
also shows filename and line number of the invalid redeclaration, we'd
have to

- pass the parser context to the entity functions somehow, or
- make these functions return distinct error codes.

Partial fix for #308.
2022-02-20 21:49:04 +01:00
Nick Wellnhofer
652dd12a85 [CVE-2022-23308] Use-after-free of ID and IDREF attributes
If a document is parsed with XML_PARSE_DTDVALID and without
XML_PARSE_NOENT, the value of ID attributes has to be normalized after
potentially expanding entities in xmlRemoveID. Otherwise, later calls
to xmlGetID can return a pointer to previously freed memory.

ID attributes which are empty or contain only whitespace after
entity expansion are affected in a similar way. This is fixed by
not storing such attributes in the ID table.

The test to detect streaming mode when validating against a DTD was
broken. In connection with the defects above, this could result in a
use-after-free when using the xmlReader interface with validation.
Fix detection of streaming mode to avoid similar issues. (This changes
the expected result of a test case. But as far as I can tell, using the
XML reader with XIncludes referencing the root document never worked
properly, anyway.)

All of these issues can result in denial of service. Using xmlReader
with validation could result in disclosure of memory via the error
channel, typically stderr. The security impact of xmlGetID returning
a pointer to freed memory depends on the application. The typical use
case of calling xmlGetID on an unmodified document is not affected.
2022-02-19 19:26:42 +01:00
Nick Wellnhofer
9edc20c154 Fix double counting of CRLF in comments
Fixes #151.
2022-02-07 20:54:07 +01:00
Nick Wellnhofer
5408c10c37 Don't normalize namespace URIs in XPointer xmlns() scheme
Namespace URIs should be compared without escaping or unescaping:

https://www.w3.org/TR/REC-xml-names/#NSNameComparison

Fixes #289.
2022-02-04 14:00:09 +01:00
Nick Wellnhofer
1c7d91abe4 Fix handling of XSD with empty namespace
An empty namespace means no default namespace.

Fixes #303.
2022-02-03 23:31:19 +01:00
Nick Wellnhofer
f480f7509c Update NewsML DTD in test suite
Switch to version 1.2 which has a clearer license.

Fixes #291.
2022-02-03 14:43:17 +01:00
Nick Wellnhofer
d85245f934 Fix regression with PEs in external DTD
Fix a regression introduced with commit a28f7d87. In some cases,
parameter entity references in external DTDs wouldn't be expanded.

Fixes #306.
2022-01-16 21:56:10 +01:00
David Kilzer
03bb929390 Fix parse failure when 4-byte character in UTF-16 BE is split across a chunk
This makes the logic in UTF16BEToUTF8() match UTF16LEToUTF8().

* encoding.c:
(UTF16LEToUTF8):
- Fix comment to describe what the code does.
(UTF16BEToUTF8):
- Fix undefined behavior which was applied to UTF16LEToUTF8() in
  2f9382033e.
- Add bounds check to while() loop which was applied to
  UTF16LEToUTF8() in be803967db.
- Do not return -2 when (in >= inend) to fix the bug.  This was
  applied to UTF16LEToUTF8() in 496a1cf592.
- Inline (<< 8) statements to match UTF16LEToUTF8().

Add the following tests and results:

  test/text-4-byte-UTF-16-BE-offset.xml
  test/text-4-byte-UTF-16-BE.xml
  test/text-4-byte-UTF-16-LE-offset.xml
  test/text-4-byte-UTF-16-LE.xml
2022-01-16 14:07:17 +01:00
Nick Wellnhofer
2732b23466 Fix regression parsing public IDs literals in HTML
Fix regression introduced when reworking htmlParsePubidLiteral in
commit 93ce33c2.

Fixes #318.
2022-01-10 13:37:59 +01:00
Nick Wellnhofer
de5b624f10 Fix handling of unexpected EOF in xmlParseContent
Readd the XML_ERR_TAG_NOT_FINISHED error on unexpected EOF which was
removed in commit 62150ed2.

This commit also introduced a regression for direct users of
xmlParseContent. Unclosed tags weren't checked.
2021-05-08 20:47:36 +02:00
Nick Wellnhofer
3e80560d4b Fix line numbers in error messages for mismatched tags
Commit 62150ed2 introduced a small regression in the error messages for
mismatched tags. This typically only affected messages after the first
mismatch, but with custom SAX handlers all line numbers would be off.

This also fixes line numbers in the SAX push parser which were never
handled correctly.
2021-05-07 11:48:11 +02:00
Nick Wellnhofer
01411e7c5e Check for invalid redeclarations of predefined entities
Implement section "4.6 Predefined Entities" of the XML 1.0 spec and
check whether redeclarations of predefined entities match the original
definitions.

Note that some test cases declared

    <!ENTITY lt "<">

But the XML spec clearly states that this is illegal:

> If the entities lt or amp are declared, they MUST be declared as
> internal entities whose replacement text is a character reference to
> the respective character (less-than sign or ampersand) being escaped;
> the double escaping is REQUIRED for these entities so that references
> to them produce a well-formed result.

Also fixes #217 but the connection is only tangential. The integer
overflow discovered by fuzzing was more related to the fact that various
parts of the parser disagreed on whether to prefer predefined entities
over their redeclarations. The whole situation is a mess and even
depends on legacy parser options. But now that redeclarations are
validated, it shouldn't make a difference.

As noted in the added comment, this is also one of the cases where
overly defensive checks can hide interesting logic bugs from fuzzers.
2021-02-08 21:51:26 +01:00
Nick Wellnhofer
79301d3d5e Fix timeout when handling recursive entities
Abort parsing early to avoid an almost infinite loop in certain error
cases involving recursive entities.

Found with libFuzzer.
2020-12-18 14:13:46 +01:00
Mike Dalessio
a67b63d183 use new htmlParseLookupCommentEnd to find comment ends
Note that the caret in error messages generated during comment parsing
may have moved by one byte.

See guidance provided on incorrectly-closed comments here:

https://html.spec.whatwg.org/multipage/parsing.html#parse-error-incorrectly-closed-comment
2020-12-16 16:12:07 +01:00
Mike Dalessio
29f5d20e84 htmlParseComment: treat --!> as if it closed the comment
See guidance provided on incorrectly-closed comments here:

https://html.spec.whatwg.org/multipage/parsing.html#parse-error-incorrectly-closed-comment
2020-12-16 16:12:07 +01:00
Mike Dalessio
e28d9347bc add test coverage for incorrectly-closed comments
this establishes the baseline behavior so that subsequent commits
which modify this behavior are clear about what's being changed.
2020-12-16 16:12:07 +01:00
Nick Wellnhofer
87d20b554c Fix regression introduced with commit 74dcc10b
The code wasn't dead after all, but I can see no reason in delaying
the XPointer evaluation. This could lead to nodes included earlier
appearing in XPointer results.
2020-08-19 13:52:08 +02:00
Nick Wellnhofer
d88df4bd48 Fix corner case with empty xi:fallback
xi:fallback could become empty after recursive expansion. Use a flag
to track whether nodes should be skipped.
2020-08-17 01:17:39 +02:00
Nick Wellnhofer
1abf2967f9 Fix exponential runtime and memory in xi:fallback processing
When creating XML_XINCLUDE_START nodes, the children of the original
xi:include node must be freed, otherwise fallback content is copied
twice, doubling runtime and memory consumption for each nested
xi:fallback/xi:include pair.

Found with libFuzzer.
2020-08-07 19:59:07 +02:00
Nick Wellnhofer
0f9817c75b Don't recurse into xi:include children in xmlXIncludeDoProcess
Otherwise, nested xi:include nodes might result in a use-after-free
if XML_PARSE_NOXINCNODE is specified.

Found with libFuzzer and ASan.
2020-08-06 14:29:33 +02:00
Nick Wellnhofer
93ce33c2b8 Fix several quadratic runtime issues in HTML push parser
Fix a few remaining cases where the HTML push parser would scan more
content during lookahead than being parsed later.

Make sure that htmlParseDocTypeDecl consumes all content up to the
final '>' in case of errors. The old comment said "We shouldn't try to
resynchronize", but ignoring invalid content is also what the HTML5
spec mandates.

Likewise, make htmlParseEndTag skip to the final '>' in invalid end
tags even if not in recovery mode. This is probably the most visible
change in practice and leads to different output for some tests but is
also more in line with HTML5.

Make sure that htmlParsePI and htmlParseComment don't abort if invalid
characters are encountered but log an error and ignore the character.

Change some other end-of-buffer checks to test for a zero byte instead
of relying on IS_CHAR.

Fix usage of IS_CHAR macro in htmlParseScript.
2020-07-23 20:47:35 +02:00
David Kilzer
6b4717d61d Add regexp regression tests
- Bug 757711: heap-buffer-overflow in xmlFAParsePosCharGroup
  <https://bugzilla.gnome.org/show_bug.cgi?id=757711>
- Bug 783015 - Integer-overflow in xmlFAParseQuantExact
  <https://bugzilla.gnome.org/show_bug.cgi?id=783015>

(Regexptests): Add support for checking stderr output when
running regexp tests.  This makes it possible to check in test
cases that fail and not see false-positive error output when
running the tests.  Unlike other libxml2 test suites, if there
is no stderr output, no *.err file needs to be created.
2020-07-06 12:37:53 +02:00
Nick Wellnhofer
477c7f6aff Fix quadratic runtime in HTML parser
Commit eeb99329 removed an important optimization avoiding quadratic
runtime when repeatedly scanning the input buffer for terminating
characters in the HTML push parser. The related bug is

    https://bugzilla.gnome.org/show_bug.cgi?id=444994

Make sure that ctxt->checkIndex is always written and store additional
parser state in ctxt->inSubset which is unused in the HTML parser.

Found by OSS-Fuzz.
2020-07-06 12:17:20 +02:00