fsck: check .gitmodules content

This patch detects and blocks submodule names which do not
match the policy set forth in submodule-config. These should
already be caught by the submodule code itself, but putting
the check here means that newer versions of Git can protect
older ones from malicious entries (e.g., a server with
receive.fsckObjects will block the objects, protecting
clients which fetch from it).

As a side effect, this means fsck will also complain about
.gitmodules files that cannot be parsed (or were larger than
core.bigFileThreshold).

Signed-off-by: Jeff King <peff@peff.net>
This commit is contained in:
Jeff King 2018-05-02 17:25:27 -04:00
parent 2738744426
commit ed8b10f631

60
fsck.c
View file

@ -12,6 +12,8 @@
#include "decorate.h"
#include "oidset.h"
#include "packfile.h"
#include "submodule-config.h"
#include "config.h"
static struct oidset gitmodules_found = OIDSET_INIT;
static struct oidset gitmodules_done = OIDSET_INIT;
@ -59,6 +61,8 @@ static struct oidset gitmodules_done = OIDSET_INIT;
FUNC(ZERO_PADDED_DATE, ERROR) \
FUNC(GITMODULES_MISSING, ERROR) \
FUNC(GITMODULES_BLOB, ERROR) \
FUNC(GITMODULES_PARSE, ERROR) \
FUNC(GITMODULES_NAME, ERROR) \
/* warnings */ \
FUNC(BAD_FILEMODE, WARN) \
FUNC(EMPTY_NAME, WARN) \
@ -911,10 +915,64 @@ static int fsck_tag(struct tag *tag, const char *data,
return fsck_tag_buffer(tag, data, size, options);
}
struct fsck_gitmodules_data {
struct object *obj;
struct fsck_options *options;
int ret;
};
static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
{
struct fsck_gitmodules_data *data = vdata;
const char *subsection, *key;
int subsection_len;
char *name;
if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
!subsection)
return 0;
name = xmemdupz(subsection, subsection_len);
if (check_submodule_name(name) < 0)
data->ret |= report(data->options, data->obj,
FSCK_MSG_GITMODULES_NAME,
"disallowed submodule name: %s",
name);
free(name);
return 0;
}
static int fsck_blob(struct blob *blob, const char *buf,
unsigned long size, struct fsck_options *options)
{
return 0;
struct fsck_gitmodules_data data;
if (!oidset_contains(&gitmodules_found, &blob->object.oid))
return 0;
oidset_insert(&gitmodules_done, &blob->object.oid);
if (!buf) {
/*
* A missing buffer here is a sign that the caller found the
* blob too gigantic to load into memory. Let's just consider
* that an error.
*/
return report(options, &blob->object,
FSCK_MSG_GITMODULES_PARSE,
".gitmodules too large to parse");
}
data.obj = &blob->object;
data.options = options;
data.ret = 0;
if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
".gitmodules", buf, size, &data))
data.ret |= report(options, &blob->object,
FSCK_MSG_GITMODULES_PARSE,
"could not parse gitmodules blob");
return data.ret;
}
int fsck_object(struct object *obj, void *data, unsigned long size,