Revision 8db1e8743c0f1ed241f6a1b8bf55b6fef07d6751 authored by Johannes Schindelin on 28 March 2024, 18:21:06 UTC, committed by Johannes Schindelin on 19 April 2024, 10:38:23 UTC
Critical security issues typically combine relatively common vulnerabilities such as case confusion in file paths with other weaknesses in order to raise the severity of the attack. One such weakness that has haunted the Git project in many a submodule-related CVE is that any hooks that are found are executed during a clone operation. Examples are the `post-checkout` and `fsmonitor` hooks. However, Git's design calls for hooks to be disabled by default, as only disabled example hooks are copied over from the templates in `<prefix>/share/git-core/templates/`. As a defense-in-depth measure, let's prevent those hooks from running. Obviously, administrators can choose to drop enabled hooks into the template directory, though, _and_ it is also possible to override `core.hooksPath`, in which case the new check needs to be disabled. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
1 parent 584de0b
reset.c
#include "git-compat-util.h"
#include "cache-tree.h"
#include "lockfile.h"
#include "refs.h"
#include "reset.h"
#include "run-command.h"
#include "tree-walk.h"
#include "tree.h"
#include "unpack-trees.h"
#include "hook.h"
static int update_refs(const struct reset_head_opts *opts,
const struct object_id *oid,
const struct object_id *head)
{
unsigned detach_head = opts->flags & RESET_HEAD_DETACH;
unsigned run_hook = opts->flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
const struct object_id *orig_head = opts->orig_head;
const char *switch_to_branch = opts->branch;
const char *reflog_branch = opts->branch_msg;
const char *reflog_head = opts->head_msg;
const char *reflog_orig_head = opts->orig_head_msg;
const char *default_reflog_action = opts->default_reflog_action;
struct object_id *old_orig = NULL, oid_old_orig;
struct strbuf msg = STRBUF_INIT;
const char *reflog_action;
size_t prefix_len;
int ret;
if ((update_orig_head && !reflog_orig_head) || !reflog_head) {
if (!default_reflog_action)
BUG("default_reflog_action must be given when reflog messages are omitted");
reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action :
default_reflog_action);
}
prefix_len = msg.len;
if (update_orig_head) {
if (!get_oid("ORIG_HEAD", &oid_old_orig))
old_orig = &oid_old_orig;
if (head) {
if (!reflog_orig_head) {
strbuf_addstr(&msg, "updating ORIG_HEAD");
reflog_orig_head = msg.buf;
}
update_ref(reflog_orig_head, "ORIG_HEAD",
orig_head ? orig_head : head,
old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
} else if (old_orig)
delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
}
if (!reflog_head) {
strbuf_setlen(&msg, prefix_len);
strbuf_addstr(&msg, "updating HEAD");
reflog_head = msg.buf;
}
if (!switch_to_branch)
ret = update_ref(reflog_head, "HEAD", oid, head,
detach_head ? REF_NO_DEREF : 0,
UPDATE_REFS_MSG_ON_ERR);
else {
ret = update_ref(reflog_branch ? reflog_branch : reflog_head,
switch_to_branch, oid, NULL, 0,
UPDATE_REFS_MSG_ON_ERR);
if (!ret)
ret = create_symref("HEAD", switch_to_branch,
reflog_head);
}
if (!ret && run_hook)
run_hooks_l("post-checkout",
oid_to_hex(head ? head : null_oid()),
oid_to_hex(oid), "1", NULL);
strbuf_release(&msg);
return ret;
}
int reset_head(struct repository *r, const struct reset_head_opts *opts)
{
const struct object_id *oid = opts->oid;
const char *switch_to_branch = opts->branch;
unsigned reset_hard = opts->flags & RESET_HEAD_HARD;
unsigned refs_only = opts->flags & RESET_HEAD_REFS_ONLY;
unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
struct object_id *head = NULL, head_oid;
struct tree_desc desc[2] = { { NULL }, { NULL } };
struct lock_file lock = LOCK_INIT;
struct unpack_trees_options unpack_tree_opts = { 0 };
struct tree *tree;
const char *action;
int ret = 0, nr = 0;
if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
BUG("Not a fully qualified branch: '%s'", switch_to_branch);
if (opts->orig_head_msg && !update_orig_head)
BUG("ORIG_HEAD reflog message given without updating ORIG_HEAD");
if (opts->branch_msg && !opts->branch)
BUG("branch reflog message given without a branch");
if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
ret = -1;
goto leave_reset_head;
}
if (!get_oid("HEAD", &head_oid)) {
head = &head_oid;
} else if (!oid || !reset_hard) {
ret = error(_("could not determine HEAD revision"));
goto leave_reset_head;
}
if (!oid)
oid = &head_oid;
if (refs_only)
return update_refs(opts, oid, head);
action = reset_hard ? "reset" : "checkout";
setup_unpack_trees_porcelain(&unpack_tree_opts, action);
unpack_tree_opts.head_idx = 1;
unpack_tree_opts.src_index = r->index;
unpack_tree_opts.dst_index = r->index;
unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
unpack_tree_opts.update = 1;
unpack_tree_opts.merge = 1;
unpack_tree_opts.preserve_ignored = 0; /* FIXME: !overwrite_ignore */
unpack_tree_opts.skip_cache_tree_update = 1;
init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
if (reset_hard)
unpack_tree_opts.reset = UNPACK_RESET_PROTECT_UNTRACKED;
if (repo_read_index_unmerged(r) < 0) {
ret = error(_("could not read index"));
goto leave_reset_head;
}
if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
ret = error(_("failed to find tree of %s"),
oid_to_hex(&head_oid));
goto leave_reset_head;
}
if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
goto leave_reset_head;
}
if (unpack_trees(nr, desc, &unpack_tree_opts)) {
ret = -1;
goto leave_reset_head;
}
tree = parse_tree_indirect(oid);
prime_cache_tree(r, r->index, tree);
if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
ret = error(_("could not write index"));
goto leave_reset_head;
}
if (oid != &head_oid || update_orig_head || switch_to_branch)
ret = update_refs(opts, oid, head);
leave_reset_head:
rollback_lock_file(&lock);
clear_unpack_trees_porcelain(&unpack_tree_opts);
while (nr)
free((void *)desc[--nr].buffer);
return ret;
}
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