From b7b1fca175f1ed7933f361028c631b9ac86d868d Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Fri, 4 May 2018 20:03:35 -0400
Subject: [PATCH] fsck: complain when .gitmodules is a symlink
We've recently forbidden .gitmodules to be a symlink in
verify_path(). And it's an easy way to circumvent our fsck
checks for .gitmodules content. So let's complain when we
see it.
Signed-off-by: Jeff King <peff@peff.net>
---
fsck.c | 11 +++++++++--
t/t7415-submodule-names.sh | 29 +++++++++++++++++++++++++++++
2 files changed, 38 insertions(+), 2 deletions(-)
diff --git a/fsck.c b/fsck.c
index 2eddfc3f74..9339f31513 100644
--- a/fsck.c
+++ b/fsck.c
@@ -63,6 +63,7 @@ static struct oidset gitmodules_done = OIDSET_INIT;
FUNC(GITMODULES_BLOB, ERROR) \
FUNC(GITMODULES_PARSE, ERROR) \
FUNC(GITMODULES_NAME, ERROR) \
+ FUNC(GITMODULES_SYMLINK, ERROR) \
/* warnings */ \
FUNC(BAD_FILEMODE, WARN) \
FUNC(EMPTY_NAME, WARN) \
@@ -576,8 +577,14 @@ static int fsck_tree(struct tree *item, struct fsck_options *options)
has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
has_zero_pad |= *(char *)desc.buffer == '0';
- if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name))
- oidset_insert(&gitmodules_found, oid);
+ if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
+ if (!S_ISLNK(mode))
+ oidset_insert(&gitmodules_found, oid);
+ else
+ retval += report(options, &item->object,
+ FSCK_MSG_GITMODULES_SYMLINK,
+ ".gitmodules is a symbolic link");
+ }
if (update_tree_entry_gently(&desc)) {
retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
diff --git a/t/t7415-submodule-names.sh b/t/t7415-submodule-names.sh
index 51361c9e2d..a770d92a55 100755
--- a/t/t7415-submodule-names.sh
+++ b/t/t7415-submodule-names.sh
@@ -122,4 +122,33 @@ test_expect_success 'transfer.fsckObjects handles odd pack (index)' '
test_must_fail git -C dst.git index-pack --strict --stdin <odd.pack
'
+test_expect_success 'fsck detects symlinked .gitmodules file' '
+ git init symlink &&
+ (
+ cd symlink &&
+
+ # Make the tree directly to avoid index restrictions.
+ #
+ # Because symlinks store the target as a blob, choose
+ # a pathname that could be parsed as a .gitmodules file
+ # to trick naive non-symlink-aware checking.
+ tricky="[foo]bar=true" &&
+ content=$(git hash-object -w ../.gitmodules) &&
+ target=$(printf "$tricky" | git hash-object -w --stdin) &&
+ tree=$(
+ {
+ printf "100644 blob $content\t$tricky\n" &&
+ printf "120000 blob $target\t.gitmodules\n"
+ } | git mktree
+ ) &&
+ commit=$(git commit-tree $tree) &&
+
+ # Check not only that we fail, but that it is due to the
+ # symlink detector; this grep string comes from the config
+ # variable name and will not be translated.
+ test_must_fail git fsck 2>output &&
+ grep gitmodulesSymlink output
+ )
+'
+
test_done
--
2.40.0