Revision 3ec804490a265f4c418a321428c12f3f18b7eff5 authored by Jeff King on 29 April 2017, 12:36:44 UTC, committed by Junio C Hamano on 05 May 2017, 03:07:27 UTC
When a remote server uses git-shell, the client side will connect to it like: ssh server "git-upload-pack 'foo.git'" and we literally exec ("git-upload-pack", "foo.git"). In early versions of upload-pack and receive-pack, we took a repository argument and nothing else. But over time they learned to accept dashed options. If the user passes a repository name that starts with a dash, the results are confusing at best (we complain of a bogus option instead of a non-existent repository) and malicious at worst (the user can start an interactive pager via "--help"). We could pass "--" to the sub-process to make sure the user's argument is interpreted as a branch name. I.e.: git-upload-pack -- -foo.git But adding "--" automatically would make us inconsistent with a normal shell (i.e., when git-shell is not in use), where "-foo.git" would still be an error. For that case, the client would have to specify the "--", but they can't do so reliably, as existing versions of git-shell do not allow more than a single argument. The simplest thing is to simply disallow "-" at the start of the repo name argument. This hasn't worked either with or without git-shell since version 1.0.0, and nobody has complained. Note that this patch just applies to do_generic_cmd(), which runs upload-pack, receive-pack, and upload-archive. There are two other types of commands that git-shell runs: - do_cvs_cmd(), but this already restricts the argument to be the literal string "server" - admin-provided commands in the git-shell-commands directory. We'll pass along arbitrary arguments there, so these commands could have similar problems. But these commands might actually understand dashed arguments, so we cannot just block them here. It's up to the writer of the commands to make sure they are safe. With great power comes great responsibility. Reported-by: Timo Schmid <tschmid@ernw.de> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 7654286
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"
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 unsigned char *sha1, int flag, void *cb_data)
{
struct object *object = parse_object_or_die(sha1, path);
struct rev_info *revs = (struct rev_info *)cb_data;
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;
unsigned long timestamp;
};
static void add_recent_object(const unsigned char *sha1,
unsigned long 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 = sha1_object_info(sha1, NULL);
if (type < 0)
die("unable to get object info for %s", sha1_to_hex(sha1));
switch (type) {
case OBJ_TAG:
case OBJ_COMMIT:
obj = parse_object_or_die(sha1, NULL);
break;
case OBJ_TREE:
obj = (struct object *)lookup_tree(sha1);
break;
case OBJ_BLOB:
obj = (struct object *)lookup_blob(sha1);
break;
default:
die("unknown object type for %s: %s",
sha1_to_hex(sha1), typename(type));
}
if (!obj)
die("unable to lookup %s", sha1_to_hex(sha1));
add_pending_object(data->revs, obj, "");
}
static int add_recent_loose(const unsigned char *sha1,
const char *path, void *data)
{
struct stat st;
struct object *obj = lookup_object(sha1);
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("unable to stat %s: %s",
sha1_to_hex(sha1), strerror(errno));
}
add_recent_object(sha1, st.st_mtime, data);
return 0;
}
static int add_recent_packed(const unsigned char *sha1,
struct packed_git *p, uint32_t pos,
void *data)
{
struct object *obj = lookup_object(sha1);
if (obj && obj->flags & SEEN)
return 0;
add_recent_object(sha1, p->mtime, data);
return 0;
}
int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
unsigned long timestamp)
{
struct recent_data data;
int r;
data.revs = revs;
data.timestamp = timestamp;
r = for_each_loose_object(add_recent_loose, &data,
FOR_EACH_OBJECT_LOCAL_ONLY);
if (r)
return r;
return for_each_packed_object(add_recent_packed, &data,
FOR_EACH_OBJECT_LOCAL_ONLY);
}
void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
unsigned long mark_recent,
struct progress *progress)
{
struct connectivity_progress cp;
/*
* 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);
/* Add all reflog info */
if (mark_reflog)
add_reflogs_to_pending(revs, 0);
cp.progress = progress;
cp.count = 0;
/*
* Set up the revision walk - this will move all commits
* from the pending list to the commit walking list.
*/
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))
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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