From: Matheus Tavares Date: Mon, 30 Sep 2019 01:50:49 GMT Subject: [PATCH v2 03/11] grep: fix racy calls in grep_objects() Message-ID: <34aeb218bf266ac1a8fabcd9e8b307130d31eb0b.1569808052.git.matheus.bernardino@usp.br> In-Reply-To: deref_tag() calls is_promisor_object() and parse_object(), both of which perform lazy initializations and other thread-unsafe operations. If it was only called by grep_objects() this wouldn't be a problem as the latter is only executed by the main thread. However, deref_tag() is also present in read_object_file()'s call stack. So calling deref_tag() in grep_objects() without acquiring the grep_read_mutex may incur in a race condition with object reading operations (such as the ones internally performed by fill_textconv(), called at fill_textconv_grep()). The same problem happens with the call to gitmodules_config_oid() which also has parse_object() in its call stack. Fix that protecting both call with the said grep_read_mutex. Signed-off-by: Matheus Tavares --- builtin/grep.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/builtin/grep.c b/builtin/grep.c index 626dbe554d..fa8b9996d1 100644 --- a/builtin/grep.c +++ b/builtin/grep.c @@ -658,13 +658,18 @@ static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec, for (i = 0; i < nr; i++) { struct object *real_obj; + + grep_read_lock(); real_obj = deref_tag(opt->repo, list->objects[i].item, NULL, 0); + grep_read_unlock(); /* load the gitmodules file for this rev */ if (recurse_submodules) { submodule_free(opt->repo); + grep_read_lock(); gitmodules_config_oid(&real_obj->oid); + grep_read_unlock(); } if (grep_object(opt, pathspec, real_obj, list->objects[i].name, list->objects[i].path)) { -- 2.23.0