When modifying git config, we xcalloc() a struct lock_file
but never free it. This is necessary because the tempfile
code (upon which the locking code is built) requires that
the resulting struct remain valid through the life of the
program. However, it also confuses leak-checkers like
valgrind because only the inner "struct tempfile" is still
reachable; no pointer to the outer lock_file is kept.

Other code paths solve this by using a single static lock
struct. We can do the same here, because we know that we'll
only lock and modify one config file at a time (and
assertions within the lockfile code will ensure that this
remains the case).

That removes a real leak (when we fail to free the struct
after locking fails) as well as removes the valgrind false
positive. It also means that doing N sequential
config-writes will use a constant amount of memory, rather
than leaving stale lock_files for each.

Note that since "lock" is no longer a pointer, it can't be
NULL anymore. But that's OK. We used that feature only to
avoid calling rollback_lock_file() on an already-committed
lock. Since the lockfile code keeps its own "active" flag,
it's a noop to rollback an inactive lock, and we don't have
to worry about this ourselves.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Git 2.11.3

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Git 2.10.4

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Git 2.9.5

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Git 2.8.6

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Git 2.7.6

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If we get a repo path like "-repo.git", we may try to invoke
"git-upload-pack -repo.git". This is going to fail, since
upload-pack will interpret it as a set of bogus options. But
let's reject this before we even run the sub-program, since
we would not want to allow any mischief with repo names that
actually are real command-line options.

You can still ask for such a path via git-daemon, but there's no
security problem there, because git-daemon enters the repo itself
and then passes "."  on the command line.
Signed-off-by: NJeff King <peff@peff.net>
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If you have a GIT_PROXY_COMMAND configured, we will run it
with the host/port on the command-line. If a URL contains a
mischievous host like "--foo", we don't know how the proxy
command may handle it. It's likely to break, but it may also
do something dangerous and unwanted (technically it could
even do something useful, but that seems unlikely).

We should err on the side of caution and reject this before
we even run the command.

The hostname check matches the one we do in a similar
circumstance for ssh. The port check is not present for ssh,
but there it's not necessary because the syntax is "-p
<port>", and there's no ambiguity on the parsing side.

It's not clear whether you can actually get a negative port
to the proxy here or not. Doing:

  git fetch git://remote:-1234/repo.git

keeps the "-1234" as part of the hostname, with the default
port of 9418. But it's a good idea to keep this check close
to the point of running the command to make it clear that
there's no way to circumvent it (and at worst it serves as a
belt-and-suspenders check).
Signed-off-by: NJeff King <peff@peff.net>
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We reject hostnames that start with a dash because they may
be confused for command-line options. Let's factor out that
notion into a helper function, as we'll use it in more
places. And while it's simple now, it's not clear if some
systems might need more complex logic to handle all cases.
Signed-off-by: NJeff King <peff@peff.net>
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Per the explanation in the previous patch, this should be
(and is) rejected.
Signed-off-by: NJeff King <peff@peff.net>
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When commands like "git fetch" talk with ssh://$rest_of_URL/, the
code splits $rest_of_URL into components like host, port, etc., and
then spawns the underlying "ssh" program by formulating argv[] array
that has:

 - the path to ssh command taken from GIT_SSH_COMMAND, etc.

 - dashed options like '-batch' (for Tortoise), '-p <port>' as
   needed.

 - ssh_host, which is supposed to be the hostname parsed out of
   $rest_of_URL.

 - then the command to be run on the other side, e.g. git
   upload-pack.

If the ssh_host ends up getting '-<anything>', the argv[] that is
used to spawn the command becomes something like:

    { "ssh", "-p", "22", "-<anything>", "command", "to", "run", NULL }

which obviously is bogus, but depending on the actual value of
"<anything>", will make "ssh" parse and use it as an option.

Prevent this by forbidding ssh_host that begins with a "-".

Noticed-by: Joern Schneeweisz of Recurity Labs
Reported-by: Brian at GitLab
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Reviewed-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The tests for protocol.allow actually set that variable in
the on-disk config, run a series of tests, and then never
clean up after themselves. This means that whatever tests we
run after have protocol.allow=never, which may influence
their results.

In most cases we either exit after running these tests, or
do another round of test_proto(). In the latter case, this happens to
work because:

  1. Tests of the GIT_ALLOW_PROTOCOL environment variable
     override the config.

  2. Tests of the specific config "protocol.foo.allow"
     override the protocol.allow config.

  3. The next round of protocol.allow tests start off by
     setting the config to a known value.

However, it's a land-mine waiting to trap somebody adding
new tests to one of the t581x test scripts. Let's make sure
we clean up after ourselves.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* jk/shell-no-repository-that-begins-with-dash:
  shell: disallow repo names beginning with dash

When a remote server uses git-shell, the client side will
connect to it like:

  ssh server "git-upload-pack 'foo.git'"

and we literally exec ("git-upload-pack", "foo.git"). In
early versions of upload-pack and receive-pack, we took a
repository argument and nothing else. But over time they
learned to accept dashed options. If the user passes a
repository name that starts with a dash, the results are
confusing at best (we complain of a bogus option instead of
a non-existent repository) and malicious at worst (the user
can start an interactive pager via "--help").

We could pass "--" to the sub-process to make sure the
user's argument is interpreted as a branch name. I.e.:

  git-upload-pack -- -foo.git

But adding "--" automatically would make us inconsistent
with a normal shell (i.e., when git-shell is not in use),
where "-foo.git" would still be an error. For that case, the
client would have to specify the "--", but they can't do so
reliably, as existing versions of git-shell do not allow
more than a single argument.

The simplest thing is to simply disallow "-" at the start of
the repo name argument. This hasn't worked either with or
without git-shell since version 1.0.0, and nobody has
complained.

Note that this patch just applies to do_generic_cmd(), which
runs upload-pack, receive-pack, and upload-archive. There
are two other types of commands that git-shell runs:

  - do_cvs_cmd(), but this already restricts the argument to
    be the literal string "server"

  - admin-provided commands in the git-shell-commands
    directory. We'll pass along arbitrary arguments there,
    so these commands could have similar problems. But these
    commands might actually understand dashed arguments, so
    we cannot just block them here. It's up to the writer of
    the commands to make sure they are safe. With great
    power comes great responsibility.
Reported-by: NTimo Schmid <tschmid@ernw.de>
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>