remote-mediawiki: use "sh" to eliminate unquoted commands
Remove the use of run_git_unquoted() completely with a use of "sh -c"
suggested by Jeff King, i.e.:
sh -c '"$@" 2>/dev/null' -- echo sneaky 'argument;id'
I don't think this is needed now for any potential RCE issue. The
$remotename argument is ultimately picked by the local user (and
similarly, the $local variable comes from a user-supplied
refspec).
But completely eliminating the use of unquoted shell arguments has a
value in and of itself, by making the code easier to review. As noted
in an earlier commit I think the use of IPC::Open3 would be too
verbose here, but this "sh -c" trick strikes the right balance between
readability and semantic sanity.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ævar Arnfjörð Bjarmason committedSep 21, 2020 at 12:40 UTC9a8606465e81a04d58c20324c402ba3464bc706a
1 file changed+8-16
contrib/mw-to-git/git-remote-mediawiki.perl
+8-16
index d21c18df7b..a5624413dc 100755--- a/contrib/mw-to-git/git-remote-mediawiki.perl+++ b/contrib/mw-to-git/git-remote-mediawiki.perl@@ -371,8 +371,8 @@ sub get_mw_pages { # usage: $out = run_git_quoted(["command", "args", ...]); # $out = run_git_quoted(["command", "args", ...], "raw"); # don't interpret output as UTF-8.-# $out = run_git_unquoted(["command args"); # don't quote arguments-# $out = run_git_unquoted(["command args", "raw"); # ditto but raw instead of UTF-8 as above+# $out = run_git_quoted_nostderr(["command", "args", ...]); # discard stderr+# $out = run_git_quoted_nostderr(["command", "args", ...], "raw"); # ditto but raw instead of UTF-8 as above sub _run_git { my $args = shift; my $encoding = (shift || 'encoding(UTF-8)');@@ -391,8 +391,8 @@ sub run_git_quoted { _run_git(["git", @{$_[0]}], $_[1]); }-sub run_git_unquoted {- _run_git(["git $_[0]"], $_[1]);+sub run_git_quoted_nostderr {+ _run_git(['sh', '-c', 'git "$@" 2>/dev/null', '--', @{$_[0]}], $_[1]); } sub get_all_mediafiles {@@ -521,10 +521,8 @@ sub download_mw_mediafile { sub get_last_local_revision { # Get note regarding last mediawiki revision.- #- # It's OK to use run_git_unquoted() here because $remotename is- # supplied by the local git itself.- my $note = run_git_unquoted("notes --ref=${remotename}/mediawiki show refs/mediawiki/${remotename}/master 2>/dev/null");+ my $note = run_git_quoted_nostderr(["notes", "--ref=${remotename}/mediawiki",+ "show", "refs/mediawiki/${remotename}/master"]); my @note_info = split(/ /, $note); my $lastrevision_number;@@ -1189,16 +1187,10 @@ sub mw_push_revision { my $mw_revision = $last_remote_revid; # Get sha1 of commit pointed by local HEAD- #- # It's OK to use run_git_unquoted() because $local is supplied- # by the local git itself.- my $HEAD_sha1 = run_git_unquoted("rev-parse ${local} 2>/dev/null");+ my $HEAD_sha1 = run_git_quoted_nostderr(["rev-parse", $local]); chomp($HEAD_sha1); # Get sha1 of commit pointed by remotes/$remotename/master- #- # It's OK to use run_git_unquoted() here because $remotename is- # supplied by the local git itself.- my $remoteorigin_sha1 = run_git_unquoted("rev-parse refs/remotes/${remotename}/master 2>/dev/null");+ my $remoteorigin_sha1 = run_git_quoted_nostderr(["rev-parse", "refs/remotes/${remotename}/master"]); chomp($remoteorigin_sha1); if ($last_local_revid > 0 &&