Documentation/RelNotes/2.30.7.adoc

Git v2.30.7 Release Notes
=========================

This release addresses the security issues CVE-2022-41903 and
CVE-2022-23521.


Fixes since v2.30.6
-------------------

 * CVE-2022-41903:

   git log has the ability to display commits using an arbitrary
   format with its --format specifiers. This functionality is also
   exposed to git archive via the export-subst gitattribute.

   When processing the padding operators (e.g., %<(, %<|(, %>(,
   %>>(, or %><( ), an integer overflow can occur in
   pretty.c::format_and_pad_commit() where a size_t is improperly
   stored as an int, and then added as an offset to a subsequent
   memcpy() call.

   This overflow can be triggered directly by a user running a
   command which invokes the commit formatting machinery (e.g., git
   log --format=...). It may also be triggered indirectly through
   git archive via the export-subst mechanism, which expands format
   specifiers inside of files within the repository during a git
   archive.

   This integer overflow can result in arbitrary heap writes, which
   may result in remote code execution.

* CVE-2022-23521:

    gitattributes are a mechanism to allow defining attributes for
    paths. These attributes can be defined by adding a `.gitattributes`
    file to the repository, which contains a set of file patterns and
    the attributes that should be set for paths matching this pattern.

    When parsing gitattributes, multiple integer overflows can occur
    when there is a huge number of path patterns, a huge number of
    attributes for a single pattern, or when the declared attribute
    names are huge.

    These overflows can be triggered via a crafted `.gitattributes` file
    that may be part of the commit history. Git silently splits lines
    longer than 2KB when parsing gitattributes from a file, but not when
    parsing them from the index. Consequentially, the failure mode
    depends on whether the file exists in the working tree, the index or
    both.

    This integer overflow can result in arbitrary heap reads and writes,
    which may result in remote code execution.

Credit for finding CVE-2022-41903 goes to Joern Schneeweisz of GitLab.
An initial fix was authored by Markus Vervier of X41 D-Sec. Credit for
finding CVE-2022-23521 goes to Markus Vervier and Eric Sesterhenn of X41
D-Sec. This work was sponsored by OSTIF.

The proposed fixes have been polished and extended to cover additional
findings by Patrick Steinhardt of GitLab, with help from others on the
Git security mailing list.

Patrick Steinhardt (21):
      attr: fix overflow when upserting attribute with overly long name
      attr: fix out-of-bounds read with huge attribute names
      attr: fix integer overflow when parsing huge attribute names
      attr: fix out-of-bounds write when parsing huge number of attributes
      attr: fix out-of-bounds read with unreasonable amount of patterns
      attr: fix integer overflow with more than INT_MAX macros
      attr: harden allocation against integer overflows
      attr: fix silently splitting up lines longer than 2048 bytes
      attr: ignore attribute lines exceeding 2048 bytes
      attr: ignore overly large gitattributes files
      pretty: fix out-of-bounds write caused by integer overflow
      pretty: fix out-of-bounds read when left-flushing with stealing
      pretty: fix out-of-bounds read when parsing invalid padding format
      pretty: fix adding linefeed when placeholder is not expanded
      pretty: fix integer overflow in wrapping format
      utf8: fix truncated string lengths in `utf8_strnwidth()`
      utf8: fix returning negative string width
      utf8: fix overflow when returning string width
      utf8: fix checking for glyph width in `strbuf_utf8_replace()`
      utf8: refactor `strbuf_utf8_replace` to not rely on preallocated buffer
      pretty: restrict input lengths for padding and wrapping formats