git_sha1 already puts "--" before its arguments, so
git_sha1_file($dir, 'doc/index.mdwn')
would have incorrectly invoked
git rev-list --max-count=1 HEAD -- -- doc/index.mdwn
If there is no file in the wiki named "--", that's harmless, because
it merely names the latest revision in which either "--" or
"doc/index.mdwn" changed. However, it could return incorrect results
if there is somehow a file named "--".
If we throw an exception (usually from run_or_die), in_git_dir won't
unshift the current directory from the stack. That's usually fine,
but in rcs_preprevert we catch exceptions and do some cleanup before
returning, for which we need the git directory to be the root and
not the temporary working tree.
We exclude .git/hooks from symlinking into the temporary working tree,
which avoids the commit hook being run for the temporary branch anyway.
This avoids the wiki not being updated if an orthogonal change is
received in process A, while process B prepares a revert that is
subsequently cancelled.
Otherwise, we have a time-of-check/time-of-use vulnerability:
rcs_preprevert previously looked at what changed in the commit we are
reverting, not at what would result from reverting it now. In
particular, if some files were renamed since the commit we are
reverting, a revert of changes that were within the designated
subdirectory and allowed by check_canchange() might now affect
files that are outside the designated subdirectory or disallowed
by check_canchange().
It is not sufficient to disable rename detection, since git older
than 2.8.0rc0 (in particular the version in Debian stable) silently
accepts and ignores the relevant options.
OVE-20161226-0002
This doesn't work prior to git 2.8: `git revert` silently ignores the
option and succeeds. We will have to fix CVE-2016-10026 some other way.
This reverts commit 9cada49ed6.
Otherwise, we have an authorization bypass vulnerability: rcs_preprevert
looks at what changed in the commit we are reverting, not at what would
result from reverting it now. In particular, if some files were renamed
since the commit we are reverting, a revert of changes that were within
the designated subdirectory and allowed by check_canchange() might now
affect files that are outside the designated subdirectory or disallowed
by check_canchange().
Signed-off-by: Simon McVittie <smcv@debian.org>
This was needed due to emailauth, but I've also wrapped all IP address
exposure in cloak(), although the function doesn't yet cloak IP addresses.
(One IP address I didn't cloak is the one that appears on the password
reset email template. That is expected to be the user's own IP address,
so ok to show it to them.)
Thanks to smcv for the pointer to
http://xmlns.com/foaf/spec/#term_mbox_sha1sum
git's behaviour when doing "git push origin" is configurable, and the
default is going to change in 2.0. In particular, if you've set
push.default to "nothing", the regression test will warn:
fatal: You didn't specify any refspecs to push, and push.default
is "nothing".
'git push origin' failed: at .../lib/IkiWiki/Plugin/git.pm line 220.
Not sure if this is needed to avoid it trying to run an editor. Probably
there is never a controlling terminal and probably git notices and does
nothing. But I'm just copying what I have in git-annex assistant here.
(Although with a much worse git version comparion, that only really works due
to luck.)
A file may have no git sha1 if it's in the underlay, or just is not checked
into git. This debug message doesn't add any value and is potentially
confusing.
When the wiki is in a subdir of the git repo, a web revert would show
in recentchanges as eg, doc/index, instead of just index.
This happened because decode_git_file caches a $prefix that is dependant
on the $git_dir setting, and the revert code runs with a different
$git_dir, which polluted the $prefix for later.
Fix this by adding a with_git_dir that juggles the variables properly.
I understand the need to avoid chdir when running git_parse_changes
for receive now. At that point, the changes have not been pushed to
the srcdir's repo yet. When running the same code for preprevert,
chdir to the srcdir is ok, and necessary.