From 4e33535ea98ac16d2163e8e9fcbba5e015881e65 Mon Sep 17 00:00:00 2001 From: Glen Choo Date: Mon, 10 Apr 2023 22:18:50 +0000 Subject: 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 "$GIT_DIR/objects" is a symlink, and if so, assume that that was the reason for the failure and report the relevant information. Ideally, dir_iterator_begin() would tell us that the real failure reason is the presence of the symlink, but (as far as I can tell) there isn't an appropriate errno value for that. Also, update Documentation/git-clone.txt to reflect that this restriction exists. Signed-off-by: Glen Choo Signed-off-by: Junio C Hamano --- Documentation/git-clone.txt | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Documentation') diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt index d6434d262d..c37c4a37f7 100644 --- a/Documentation/git-clone.txt +++ b/Documentation/git-clone.txt @@ -58,6 +58,11 @@ never use the local optimizations). Specifying `--no-local` will override the default when `/path/to/repo` is given, using the regular Git transport instead. + +If the repository's `$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`. -- cgit v1.3