[ANNOUNCE] Git v2.38.1 and others

[Junio C Hamano]

A maintenance release v2.38.1, together with releases for older
maintenance tracks v2.30.6, v2.31.5, v2.32.4, v2.33.5, v2.34.5,
v2.35.5, v2.36.3, and v2.37.4, are now available at the usual
places.

These maintenance releases are to address the security issues
identified as CVE-2022-39253 and CVE-2022-39260.

The tarballs are found at:

    https://www.kernel.org/pub/software/scm/git/

The following public repositories all have a copy of the v2.38.1
tag, as well as the tags for older maintenance tracks for v2.30.6,
v2.31.5, v2.32.4, v2.33.5, v2.34.5, v2.35.5, v2.36.3, and v2.37.4.

  url = https://git.kernel.org/pub/scm/git/git
  url = https://kernel.googlesource.com/pub/scm/git/git
  url = git://repo.or.cz/alt-git.git
  url = https://github.com/gitster/git

CVE-2022-39253:
   When relying on the `--local` clone optimization, Git dereferences
   symbolic links in the source repository before creating hardlinks
   (or copies) of the dereferenced link in the destination repository.
   This can lead to surprising behavior where arbitrary files are
   present in a repository's `$GIT_DIR` when cloning from a malicious
   repository.

   Git will no longer dereference symbolic links via the `--local`
   clone mechanism, and will instead refuse to clone repositories that
   have symbolic links present in the `$GIT_DIR/objects` directory.

   Additionally, the value of `protocol.file.allow` is changed to be
   "user" by default.

CVE-2022-39260:
   An overly-long command string given to `git shell` can result in
   overflow in `split_cmdline()`, leading to arbitrary heap writes and
   remote code execution when `git shell` is exposed and the directory
   `$HOME/git-shell-commands` exists.

   `git shell` is taught to refuse interactive commands that are
   longer than 4MiB in size. `split_cmdline()` is hardened to reject
   inputs larger than 2GiB.

Credit for finding CVE-2022-39253 goes to Cory Snider of Mirantis. The
fix was authored by Taylor Blau, with help from Johannes Schindelin.

Credit for finding CVE-2022-39260 goes to Kevin Backhouse of GitHub.
The fix was authored by Kevin Backhouse, Jeff King, and Taylor Blau.