Revision 9cf85473209ea8ae2b56c13145c4704d12ee1374 authored by Filip Hejsek on 28 January 2024, 04:09:17 UTC, committed by Johannes Schindelin on 17 April 2024, 20:30:01 UTC
While it is expected to have several git dirs within the `.git/modules/` tree, it is important that they do not interfere with each other. For example, if one submodule was called "captain" and another submodule "captain/hooks", their respective git dirs would clash, as they would be located in `.git/modules/captain/` and `.git/modules/captain/hooks/`, respectively, i.e. the latter's files could clash with the actual Git hooks of the former. To prevent these clashes, and in particular to prevent hooks from being written and then executed as part of a recursive clone, we introduced checks as part of the fix for CVE-2019-1387 in a8dee3ca61 (Disallow dubiously-nested submodule git directories, 2019-10-01). It is currently possible to bypass the check for clashing submodule git dirs in two ways: 1. parallel cloning 2. checkout --recurse-submodules Let's check not only before, but also after parallel cloning (and before checking out the submodule), that the git dir is not clashing with another one, otherwise fail. This addresses the parallel cloning issue. As to the parallel checkout issue: It requires quite a few manual steps to create clashing git dirs because Git itself would refuse to initialize the inner one, as demonstrated by the test case. Nevertheless, let's teach the recursive checkout (namely, the `submodule_move_head()` function that is used by the recursive checkout) to be careful to verify that it does not use a clashing git dir, and if it does, disable it (by deleting the `HEAD` file so that subsequent Git calls won't recognize it as a git dir anymore). Note: The parallel cloning test case contains a `cat err` that proved to be highly useful when analyzing the racy nature of the operation (the operation can fail with three different error messages, depending on timing), and was left on purpose to ease future debugging should the need arise. Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
1 parent b20c10f
reachable.c
#include "cache.h"
#include "refs.h"
#include "tag.h"
#include "commit.h"
#include "blob.h"
#include "diff.h"
#include "revision.h"
#include "reachable.h"
#include "cache-tree.h"
#include "progress.h"
#include "list-objects.h"
#include "packfile.h"
#include "worktree.h"
#include "object-store.h"
#include "pack-bitmap.h"
#include "pack-mtimes.h"
struct connectivity_progress {
struct progress *progress;
unsigned long count;
};
static void update_progress(struct connectivity_progress *cp)
{
cp->count++;
if ((cp->count & 1023) == 0)
display_progress(cp->progress, cp->count);
}
static int add_one_ref(const char *path, const struct object_id *oid,
int flag, void *cb_data)
{
struct rev_info *revs = (struct rev_info *)cb_data;
struct object *object;
if ((flag & REF_ISSYMREF) && (flag & REF_ISBROKEN)) {
warning("symbolic ref is dangling: %s", path);
return 0;
}
object = parse_object_or_die(oid, path);
add_pending_object(revs, object, "");
return 0;
}
/*
* The traversal will have already marked us as SEEN, so we
* only need to handle any progress reporting here.
*/
static void mark_object(struct object *obj, const char *name, void *data)
{
update_progress(data);
}
static void mark_commit(struct commit *c, void *data)
{
mark_object(&c->object, NULL, data);
}
struct recent_data {
struct rev_info *revs;
timestamp_t timestamp;
report_recent_object_fn *cb;
int ignore_in_core_kept_packs;
};
static void add_recent_object(const struct object_id *oid,
struct packed_git *pack,
off_t offset,
timestamp_t mtime,
struct recent_data *data)
{
struct object *obj;
enum object_type type;
if (mtime <= data->timestamp)
return;
/*
* We do not want to call parse_object here, because
* inflating blobs and trees could be very expensive.
* However, we do need to know the correct type for
* later processing, and the revision machinery expects
* commits and tags to have been parsed.
*/
type = oid_object_info(the_repository, oid, NULL);
if (type < 0)
die("unable to get object info for %s", oid_to_hex(oid));
switch (type) {
case OBJ_TAG:
case OBJ_COMMIT:
obj = parse_object_or_die(oid, NULL);
break;
case OBJ_TREE:
obj = (struct object *)lookup_tree(the_repository, oid);
break;
case OBJ_BLOB:
obj = (struct object *)lookup_blob(the_repository, oid);
break;
default:
die("unknown object type for %s: %s",
oid_to_hex(oid), type_name(type));
}
if (!obj)
die("unable to lookup %s", oid_to_hex(oid));
add_pending_object(data->revs, obj, "");
if (data->cb)
data->cb(obj, pack, offset, mtime);
}
static int want_recent_object(struct recent_data *data,
const struct object_id *oid)
{
if (data->ignore_in_core_kept_packs &&
has_object_kept_pack(oid, IN_CORE_KEEP_PACKS))
return 0;
return 1;
}
static int add_recent_loose(const struct object_id *oid,
const char *path, void *data)
{
struct stat st;
struct object *obj;
if (!want_recent_object(data, oid))
return 0;
obj = lookup_object(the_repository, oid);
if (obj && obj->flags & SEEN)
return 0;
if (stat(path, &st) < 0) {
/*
* It's OK if an object went away during our iteration; this
* could be due to a simultaneous repack. But anything else
* we should abort, since we might then fail to mark objects
* which should not be pruned.
*/
if (errno == ENOENT)
return 0;
return error_errno("unable to stat %s", oid_to_hex(oid));
}
add_recent_object(oid, NULL, 0, st.st_mtime, data);
return 0;
}
static int add_recent_packed(const struct object_id *oid,
struct packed_git *p, uint32_t pos,
void *data)
{
struct object *obj;
timestamp_t mtime = p->mtime;
if (!want_recent_object(data, oid))
return 0;
obj = lookup_object(the_repository, oid);
if (obj && obj->flags & SEEN)
return 0;
if (p->is_cruft) {
if (load_pack_mtimes(p) < 0)
die(_("could not load cruft pack .mtimes"));
mtime = nth_packed_mtime(p, pos);
}
add_recent_object(oid, p, nth_packed_object_offset(p, pos), mtime, data);
return 0;
}
int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
timestamp_t timestamp,
report_recent_object_fn *cb,
int ignore_in_core_kept_packs)
{
struct recent_data data;
enum for_each_object_flags flags;
int r;
data.revs = revs;
data.timestamp = timestamp;
data.cb = cb;
data.ignore_in_core_kept_packs = ignore_in_core_kept_packs;
r = for_each_loose_object(add_recent_loose, &data,
FOR_EACH_OBJECT_LOCAL_ONLY);
if (r)
return r;
flags = FOR_EACH_OBJECT_LOCAL_ONLY | FOR_EACH_OBJECT_PACK_ORDER;
if (ignore_in_core_kept_packs)
flags |= FOR_EACH_OBJECT_SKIP_IN_CORE_KEPT_PACKS;
return for_each_packed_object(add_recent_packed, &data, flags);
}
static int mark_object_seen(const struct object_id *oid,
enum object_type type,
int exclude,
uint32_t name_hash,
struct packed_git *found_pack,
off_t found_offset)
{
struct object *obj = lookup_object_by_type(the_repository, oid, type);
if (!obj)
die("unable to create object '%s'", oid_to_hex(oid));
obj->flags |= SEEN;
return 0;
}
void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
timestamp_t mark_recent, struct progress *progress)
{
struct connectivity_progress cp;
struct bitmap_index *bitmap_git;
/*
* Set up revision parsing, and mark us as being interested
* in all object types, not just commits.
*/
revs->tag_objects = 1;
revs->blob_objects = 1;
revs->tree_objects = 1;
/* Add all refs from the index file */
add_index_objects_to_pending(revs, 0);
/* Add all external refs */
for_each_ref(add_one_ref, revs);
/* detached HEAD is not included in the list above */
head_ref(add_one_ref, revs);
other_head_refs(add_one_ref, revs);
/* Add all reflog info */
if (mark_reflog)
add_reflogs_to_pending(revs, 0);
cp.progress = progress;
cp.count = 0;
bitmap_git = prepare_bitmap_walk(revs, 0);
if (bitmap_git) {
traverse_bitmap_commit_list(bitmap_git, revs, mark_object_seen);
free_bitmap_index(bitmap_git);
} else {
if (prepare_revision_walk(revs))
die("revision walk setup failed");
traverse_commit_list(revs, mark_commit, mark_object, &cp);
}
if (mark_recent) {
revs->ignore_missing_links = 1;
if (add_unseen_recent_objects_to_traversal(revs, mark_recent,
NULL, 0))
die("unable to mark recent objects");
if (prepare_revision_walk(revs))
die("revision walk setup failed");
traverse_commit_list(revs, mark_commit, mark_object, &cp);
}
display_progress(cp.progress, cp.count);
}
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