[oss-fuzz 43589] Input triggering assertion #174
Labels
Comments
netbsd-srcmastr
pushed a commit
to NetBSD/pkgsrc
that referenced
this issue
Jan 25, 2024
## Version 0.5.1
Changes:
* LaTeX math extension (`MD_FLAG_LATEXMATHSPANS`) now requires that opener
mark is not immediately preceded with alpha-numeric character and similarly
that closer mark is not immediately followed with alpha-numeric character.
So for example `foo$ x + y = z $` is not recognized as LaTeX equation
anymore because there is no space between `foo` and the opening `$`.
* Table extension (`MD_FLAG_TABLES`) now recognizes only tables with no more
than 128 columns. This limit has been imposed to prevent a pathological
case of quadratic output size explosion which could be used as DoS attack
vector.
* We are now more strict with `MD_FLAG_PERMISSIVExxxAUTOLINKS` family of
extensions with respect to non-alphanumeric characters, with the aim to
mitigate false positive detections.
Only relatively few selected non-alphanumeric are now allowed in permissive
e-mail auto-links (`MD_FLAG_PERMISSIVEEMAILAUTOLINKS`):
- `.`, `-`, `_`, `+` in user name part of e-mail address; and
- `.`, `-`, `_` in host part of the e-mail address.
Similarly for URL and e-mail auto-links (`MD_FLAG_PERMISSIVEURLAUTOLINKS` and
`MD_FLAG_PERMISSIVEWWWAUTOLINKS`):
- `.`, `-`, `_` in host part of the URL;
- `/`, `.`, `-`, `_` in path part of the URL;
- `&`, `.`, `-`, `+`, `_`, `=`, `(`, `)` in the query part of the URL
(additionally, if present, `(` and `)` must form balanced pairs); and
- `.`, `-`, `+`, `_` in the fragment part of the URL.
Furthermore these characters (with some exceptions like where they serve as
delimiter characters, e.g. `/` for paths) are generally accepted only when
an alphanumeric character both precedes and follows them (i.e. these cannot
be "stacked" together).
Fixes:
* Fix several bugs where we haven't properly respected already resolved spans
of higher precedence level in handling of permissive auto-links extensions
(family of `MD_FLAG_PERMISSIVExxxAUTOLINKS` flags), LaTeX math extension
(`MD_FLAG_LATEXMATHSPANS`) and wiki-links extension (`MD_FLAG_WIKILINKS`)
of the form `[[label|text]]` (with pipe `|`). In some complex cases this
could lead to invalid internal parser state and memory corruption.
Identified with [OSS-Fuzz](https://github.com/google/oss-fuzz).
* [#222](mity/md4c#222):
Fix strike-through extension (`MD_FLAG_STRIKETHROUGH`) which did not respect
same rules for pairing opener and closer marks as other emphasis spans.
* [#223](mity/md4c#223):
Fix incorrect handling of new-line character just at the beginning and/or
end of a code span where we were not following CommonMark specification
requirements correctly.
## Version 0.5.0
Changes:
* Changes mandated by CommonMark specification 0.30.
Actually there are only very minor changes to recognition of HTML blocks:
- The tag `<textarea>` now triggers HTML block (of type 1 as per the
specification).
- HTML declaration (HTML block type 4) is not required to begin with an
upper-case ASCII character after the `<!`. Any ASCII character is now
allowed. Also it now doesn't require a whitespace before the closing `>`.
Other than that, the newest specification mainly improves test coverage and
clarifies its wording in some cases, without affecting the implementation.
Refer to [CommonMark
0.30 notes](https://github.com/commonmark/commonmark-spec/releases/tag/0.30)
for more info.
* Make Unicode-specific code compliant to Unicode 15.1.
* Update list of entities known to the HTML renderer from
https://html.spec.whatwg.org/entities.json.
New Features:
* Add extension allowing to treat all soft break as hard ones. It has to be
explicitly enabled with `MD_FLAG_HARD_SOFT_BREAKS`.
Contributed by [l-m](https://github.com/l1mey112).
* Structure `MD_SPAN_A_DETAIL` now has a new member `is_autolink`.
Contributed by [Jens Alfke](https://github.com/snej).
* `md2html` utility now supports command line options `--html-title` and
`--html-css`.
Contributed by [Andreas Baumann](https://github.com/andreasbaumann).
Fixes:
* [#163](mity/md4c#163):
Make HTML renderer to emit `'\n'` after the root tag when in the XHTML mode.
* [#165](mity/md4c#165):
Make HTML renderer not to percent-encode `'~'` in URLs. Although it does
work, it's not needed, and it can actually be confusing with URLs such as
`http://www.example.com/~johndoe/`.
* [#167](mity/md4c#167),
[#168](mity/md4c#168):
Fix multiple instances of various buffer overflow bugs, found mostly using
a fuzz testing. Contributed by [dtldarek](https://github.com/dtldarek) and
[Thierry Coppey](https://github.com/TCKnet).
* [#169](mity/md4c#169):
Table underline now does not require 3 characters per table column anymore.
One dash (optionally with a leading or tailing `:` appended or prepended)
is now sufficient. This improves compatibility with the GFM.
* [#172](mity/md4c#172):
Fix quadratic time behavior caused by unnecessary lookup for link reference
definition even if the potential label contains nested brackets.
* [#173](mity/md4c#173),
[#174](mity/md4c#174),
[#212](mity/md4c#212),
[#213](mity/md4c#213):
Multiple bugs identified with [OSS-Fuzz](https://github.com/google/oss-fuzz)
were fixed.
* [#190](mity/md4c#190),
[#200](mity/md4c#200),
[#201](mity/md4c#201):
Multiple fixes of incorrect interactions of indented code block with a
preceding block.
* [#202](mity/md4c#202):
We were not correctly calling `enter_block()` and `leave_block()` callbacks
if multiple HTML blocks followed one after another; instead previously
such blocks were merged into one.
(This may likely impact only applications interested in Markdown's AST,
and not just converting Markdown to other formats like HTML.)
* [#210](mity/md4c#210):
The `md2html` utility now handles nested images with optional titles
correctly.
* [#214](mity/md4c#214):
Tags `<h2>` ... `<h6>` incorrectly did not trigger HTML block.
* [#215](mity/md4c#215):
The parser incorrectly did not accept optional tabs after setext header
underline.
* [#217](mity/md4c#217):
The parser incorrectly resolved emphasis in some situations, if the emphasis
marks were enclosed by punctuation characters.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
(Distilled from https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=43589)
With
--flatex-math --fwiki-links, the following input triggers an assertion:The text was updated successfully, but these errors were encountered: