fsck: reject submodule.update = !command in .gitmodules
This allows hosting providers to detect whether they are being used
to attack users using malicious 'update = !command' settings in
.gitmodules.
Since ac1fbbda2013 (submodule: do not copy unknown update mode from
.gitmodules, 2013-12-02), in normal cases such settings have been
treated as 'update = none', so forbidding them should not produce any
collateral damage to legitimate uses. A quick search does not reveal
any repositories making use of this construct, either.
Reported-by: Joern Schneeweisz <jschneeweisz@gitlab.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
diff --git a/fsck.c b/fsck.c
index 2fc6bbc..0741e62 100644
--- a/fsck.c
+++ b/fsck.c
@@ -66,6 +66,7 @@ static struct oidset gitmodules_done = OIDSET_INIT;
FUNC(GITMODULES_SYMLINK, ERROR) \
FUNC(GITMODULES_URL, ERROR) \
FUNC(GITMODULES_PATH, ERROR) \
+ FUNC(GITMODULES_UPDATE, ERROR) \
/* warnings */ \
FUNC(BAD_FILEMODE, WARN) \
FUNC(EMPTY_NAME, WARN) \
@@ -975,6 +976,12 @@ static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
FSCK_MSG_GITMODULES_PATH,
"disallowed submodule path: %s",
value);
+ if (!strcmp(key, "update") && value &&
+ parse_submodule_update_type(value) == SM_UPDATE_COMMAND)
+ data->ret |= report(data->options, data->obj,
+ FSCK_MSG_GITMODULES_UPDATE,
+ "disallowed submodule update setting: %s",
+ value);
free(name);
return 0;
