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| author | Glen Choo <chooglen@google.com> | 2023-04-10 22:18:50 +0000 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2023-04-11 08:46:09 -0700 |
| commit | 4e33535ea98ac16d2163e8e9fcbba5e015881e65 (patch) | |
| tree | 73ea3c27e42422c1ee5282951e7f78689395aa09 | |
| parent | f285f68a132109c234d93490671c00218066ace9 (diff) | |
| download | git-4e33535ea98ac16d2163e8e9fcbba5e015881e65.tar.xz | |
clone: error specifically with --local and symlinked objects
6f054f9fb3 (builtin/clone.c: disallow --local clones with
symlinks, 2022-07-28) gives a good error message when "git clone
--local" fails when the repo to clone has symlinks in
"$GIT_DIR/objects". In bffc762f87 (dir-iterator: prevent top-level
symlinks without FOLLOW_SYMLINKS, 2023-01-24), we later extended this
restriction to the case where "$GIT_DIR/objects" is itself a symlink,
but we didn't update the error message then - bffc762f87's tests show
that we print a generic "failed to start iterator over" message.
This is exacerbated by the fact that Documentation/git-clone.txt
mentions neither restriction, so users are left wondering if this is
intentional behavior or not.
Fix this by adding a check to builtin/clone.c: when doing a local clone,
perform an extra check to see if "$GIT_DIR/objects" is a symlink, and if
so, assume that that was the reason for the failure and report the
relevant information. Ideally, dir_iterator_begin() would tell us that
the real failure reason is the presence of the symlink, but (as far as I
can tell) there isn't an appropriate errno value for that.
Also, update Documentation/git-clone.txt to reflect that this
restriction exists.
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | Documentation/git-clone.txt | 5 | ||||
| -rw-r--r-- | builtin/clone.c | 12 | ||||
| -rwxr-xr-x | t/t5604-clone-reference.sh | 2 |
3 files changed, 17 insertions, 2 deletions
diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt index d6434d262d..c37c4a37f7 100644 --- a/Documentation/git-clone.txt +++ b/Documentation/git-clone.txt @@ -58,6 +58,11 @@ never use the local optimizations). Specifying `--no-local` will override the default when `/path/to/repo` is given, using the regular Git transport instead. + +If the repository's `$GIT_DIR/objects` has symbolic links or is a +symbolic link, the clone will fail. This is a security measure to +prevent the unintentional copying of files by dereferencing the symbolic +links. ++ *NOTE*: this operation can race with concurrent modification to the source repository, similar to running `cp -r src dst` while modifying `src`. diff --git a/builtin/clone.c b/builtin/clone.c index c171def1f3..ae2db8535a 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -331,8 +331,18 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest, iter = dir_iterator_begin(src->buf, DIR_ITERATOR_PEDANTIC); - if (!iter) + if (!iter) { + if (errno == ENOTDIR) { + int saved_errno = errno; + struct stat st; + + if (!lstat(src->buf, &st) && S_ISLNK(st.st_mode)) + die(_("'%s' is a symlink, refusing to clone with --local"), + src->buf); + errno = saved_errno; + } die_errno(_("failed to start iterator over '%s'"), src->buf); + } strbuf_addch(src, '/'); src_len = src->len; diff --git a/t/t5604-clone-reference.sh b/t/t5604-clone-reference.sh index 83e3c97861..9845fc04d5 100755 --- a/t/t5604-clone-reference.sh +++ b/t/t5604-clone-reference.sh @@ -358,7 +358,7 @@ test_expect_success SYMLINKS 'clone repo with symlinked objects directory' ' test_must_fail git clone --local malicious clone 2>err && test_path_is_missing clone && - grep "failed to start iterator over" err + grep "is a symlink, refusing to clone with --local" err ' test_done |