From bb6832d5529a75164acca7c0412657c96a9a5764 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Mon, 3 May 2021 16:43:25 -0400 Subject: [PATCH] fsck: warn about symlinked dotfiles we'll open with O_NOFOLLOW In the commits merged in via 204333b015 (Merge branch 'jk/open-dotgitx-with-nofollow', 2021-03-22), we stopped following symbolic links for .gitattributes, .gitignore, and .mailmap files. Let's teach fsck to warn that these symlinks are not going to do anything. Note that this is just a warning, and won't block the objects via transfer.fsckObjects, since there are reported to be cases of this in the wild (and even once fixed, they will continue to exist in the commit history of those projects, but are not particularly dangerous). Note that we won't add these to the existing gitmodules block in the fsck code. The logic for gitmodules is a bit more complicated, as we also check the content of non-symlink instances we find. But for these new files, there is no content check; we're just looking at the name and mode of the tree entry (and we can avoid even the complicated name checks in the common case that the mode doesn't indicate a symlink). We can reuse the test helper function we defined for .gitmodules, though (it needs some slight adjustments for the fsck error code, and because we don't block these symlinks via verify_path()). Note that I didn't explicitly test the transfer.fsckObjects case here (nor does the existing .gitmodules test that it blocks a push). The translation of fsck severities to outcomes is covered in general in t5504. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- fsck.c | 18 ++++++++++++++++++ fsck.h | 3 +++ t/t7450-bad-git-dotfiles.sh | 29 +++++++++++++++++++++++++++-- 3 files changed, 48 insertions(+), 2 deletions(-) diff --git a/fsck.c b/fsck.c index db948178980..3ec500d707a 100644 --- a/fsck.c +++ b/fsck.c @@ -614,6 +614,24 @@ static int fsck_tree(const struct object_id *tree_oid, ".gitmodules is a symbolic link"); } + if (S_ISLNK(mode)) { + if (is_hfs_dotgitignore(name) || + is_ntfs_dotgitignore(name)) + retval += report(options, tree_oid, OBJ_TREE, + FSCK_MSG_GITIGNORE_SYMLINK, + ".gitignore is a symlink"); + if (is_hfs_dotgitattributes(name) || + is_ntfs_dotgitattributes(name)) + retval += report(options, tree_oid, OBJ_TREE, + FSCK_MSG_GITATTRIBUTES_SYMLINK, + ".gitattributes is a symlink"); + if (is_hfs_dotmailmap(name) || + is_ntfs_dotmailmap(name)) + retval += report(options, tree_oid, OBJ_TREE, + FSCK_MSG_MAILMAP_SYMLINK, + ".mailmap is a symlink"); + } + if ((backslash = strchr(name, '\\'))) { while (backslash) { backslash++; diff --git a/fsck.h b/fsck.h index 7202c3c87e8..d07f7a2459e 100644 --- a/fsck.h +++ b/fsck.h @@ -67,6 +67,9 @@ enum fsck_msg_type { FUNC(NUL_IN_COMMIT, WARN) \ /* infos (reported as warnings, but ignored by default) */ \ FUNC(GITMODULES_PARSE, INFO) \ + FUNC(GITIGNORE_SYMLINK, INFO) \ + FUNC(GITATTRIBUTES_SYMLINK, INFO) \ + FUNC(MAILMAP_SYMLINK, INFO) \ FUNC(BAD_TAG_NAME, INFO) \ FUNC(MISSING_TAGGER_ENTRY, INFO) \ /* ignored (elevated when requested) */ \ diff --git a/t/t7450-bad-git-dotfiles.sh b/t/t7450-bad-git-dotfiles.sh index b494d72976a..e2773bb06d4 100755 --- a/t/t7450-bad-git-dotfiles.sh +++ b/t/t7450-bad-git-dotfiles.sh @@ -140,6 +140,18 @@ test_expect_success 'index-pack --strict works for non-repo pack' ' ' check_dotx_symlink () { + fsck_must_fail=test_must_fail + fsck_prefix=error + refuse_index=t + case "$1" in + --warning) + fsck_must_fail= + fsck_prefix=warning + refuse_index= + shift + ;; + esac + name=$1 type=$2 path=$3 @@ -172,11 +184,12 @@ check_dotx_symlink () { # Check not only that we fail, but that it is due to the # symlink detector - test_must_fail git fsck 2>output && - grep "tree $tree: ${name}Symlink" output + $fsck_must_fail git fsck 2>output && + grep "$fsck_prefix.*tree $tree: ${name}Symlink" output ) ' + test -n "$refuse_index" && test_expect_success "refuse to load symlinked $name into index ($type)" ' test_must_fail \ git -C $dir \ @@ -193,6 +206,18 @@ check_dotx_symlink gitmodules vanilla .gitmodules check_dotx_symlink gitmodules ntfs ".gitmodules ." check_dotx_symlink gitmodules hfs ".${u200c}gitmodules" +check_dotx_symlink --warning gitattributes vanilla .gitattributes +check_dotx_symlink --warning gitattributes ntfs ".gitattributes ." +check_dotx_symlink --warning gitattributes hfs ".${u200c}gitattributes" + +check_dotx_symlink --warning gitignore vanilla .gitignore +check_dotx_symlink --warning gitignore ntfs ".gitignore ." +check_dotx_symlink --warning gitignore hfs ".${u200c}gitignore" + +check_dotx_symlink --warning mailmap vanilla .mailmap +check_dotx_symlink --warning mailmap ntfs ".mailmap ." +check_dotx_symlink --warning mailmap hfs ".${u200c}mailmap" + test_expect_success 'fsck detects non-blob .gitmodules' ' git init non-blob && (