@matheusbsbs / matheus-bagliano / commits / 1a7fd1fb29

fsck: detect submodule paths starting with dash

As with urls, submodule paths with dashes are ignored by git, but may end up confusing older versions. Detecting them via fsck lets us prevent modern versions of git from being a vector to spread broken .gitmodules to older versions. Compared to blocking leading-dash urls, though, this detection may be less of a good idea: 1. While such paths provide confusing and broken results, they don't seem to actually work as option injections against anything except "cd". In particular, the submodule code seems to canonicalize to an absolute path before running "git clone" (so it passes /your/clone/-sub). 2. It's more likely that we may one day make such names actually work correctly. Even after we revert this fsck check, it will continue to be a hassle until hosting servers are all updated. On the other hand, it's not entirely clear that the behavior in older versions is safe. And if we do want to eventually allow this, we may end up doing so with a special syntax anyway (e.g., writing "./-sub" in the .gitmodules file, and teaching the submodule code to canonicalize it when comparing). So on balance, this is probably a good protection. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Sep 24, 2018 at 04:42 UTC 1a7fd1fb2998002da6e9ff2ee46e1bdd25ee8404

2 files changed +15

fsck.c

@@ -65,6 +65,7 @@ static struct oidset gitmodules_done = OIDSET_INIT;

65 FUNC(GITMODULES_NAME, ERROR) \

66 FUNC(GITMODULES_SYMLINK, ERROR) \

67 FUNC(GITMODULES_URL, ERROR) \

68 + FUNC(GITMODULES_PATH, ERROR) \

69 /* warnings */ \

70 FUNC(BAD_FILEMODE, WARN) \

71 FUNC(EMPTY_NAME, WARN) \

@@ -952,6 +953,12 @@ static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)

953 FSCK_MSG_GITMODULES_URL,

954 "disallowed submodule url: %s",

955 value);

956 + if (!strcmp(key, "path") && value &&

957 + looks_like_command_line_option(value))

958 + data->ret |= report(data->options, data->obj,

959 + FSCK_MSG_GITMODULES_PATH,

960 + "disallowed submodule path: %s",

961 + value);

962 free(name);

963

964 return 0;

t/t7417-submodule-path-url.sh

@@ -17,4 +17,12 @@ test_expect_success 'clone rejects unprotected dash' '

17 test_i18ngrep ignoring err

18 '

20 +test_expect_success 'fsck rejects unprotected dash' '

21 + test_when_finished "rm -rf dst" &&

22 + git init --bare dst &&

23 + git -C dst config transfer.fsckObjects true &&

24 + test_must_fail git push dst HEAD 2>err &&

25 + grep gitmodulesPath err

26 +'

27 +

28 test_done