set_git_dir: fix crash when used with real_path()
`real_path()` returns result from a shared buffer, inviting subtle
reentrance bugs. One of these bugs occur when invoked this way:
set_git_dir(real_path(git_dir))
In this case, `real_path()` has reentrance:
real_path
read_gitfile_gently
repo_set_gitdir
setup_git_env
set_git_dir_1
set_git_dir
Later, `set_git_dir()` uses its now-dead parameter:
!is_absolute_path(path)
Fix this by using a dedicated `strbuf` to hold `strbuf_realpath()`.
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/init-db.c b/builtin/init-db.c
index 944ec77..5bf61a7 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -356,12 +356,12 @@
if (!exist_ok && !stat(real_git_dir, &st))
die(_("%s already exists"), real_git_dir);
- set_git_dir(real_path(real_git_dir));
+ set_git_dir(real_git_dir, 1);
git_dir = get_git_dir();
separate_git_dir(git_dir, original_git_dir);
}
else {
- set_git_dir(real_path(git_dir));
+ set_git_dir(git_dir, 1);
git_dir = get_git_dir();
}
startup_info->have_repository = 1;
diff --git a/cache.h b/cache.h
index 37c899b..8cee257 100644
--- a/cache.h
+++ b/cache.h
@@ -543,7 +543,7 @@
char *get_object_directory(void);
char *get_index_file(void);
char *get_graft_file(struct repository *r);
-void set_git_dir(const char *path);
+void set_git_dir(const char *path, int make_realpath);
int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
int get_common_dir(struct strbuf *sb, const char *gitdir);
const char *get_git_namespace(void);
diff --git a/environment.c b/environment.c
index e72a02d..c436de3 100644
--- a/environment.c
+++ b/environment.c
@@ -345,11 +345,20 @@
free(path);
}
-void set_git_dir(const char *path)
+void set_git_dir(const char *path, int make_realpath)
{
+ struct strbuf realpath = STRBUF_INIT;
+
+ if (make_realpath) {
+ strbuf_realpath(&realpath, path, 1);
+ path = realpath.buf;
+ }
+
set_git_dir_1(path);
if (!is_absolute_path(path))
chdir_notify_register(NULL, update_relative_gitdir, NULL);
+
+ strbuf_release(&realpath);
}
const char *get_log_output_encoding(void)
diff --git a/path.c b/path.c
index 88cf593..c5a8fe4 100644
--- a/path.c
+++ b/path.c
@@ -850,7 +850,7 @@
}
if (is_git_directory(".")) {
- set_git_dir(".");
+ set_git_dir(".", 0);
check_repository_format();
return path;
}
diff --git a/setup.c b/setup.c
index 4ea7a0b..fa4317e 100644
--- a/setup.c
+++ b/setup.c
@@ -725,7 +725,7 @@
}
/* #18, #26 */
- set_git_dir(gitdirenv);
+ set_git_dir(gitdirenv, 0);
free(gitfile);
return NULL;
}
@@ -747,7 +747,7 @@
}
else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
/* #16d */
- set_git_dir(gitdirenv);
+ set_git_dir(gitdirenv, 0);
free(gitfile);
return NULL;
}
@@ -759,14 +759,14 @@
/* both get_git_work_tree() and cwd are already normalized */
if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
- set_git_dir(gitdirenv);
+ set_git_dir(gitdirenv, 0);
free(gitfile);
return NULL;
}
offset = dir_inside_of(cwd->buf, worktree);
if (offset >= 0) { /* cwd inside worktree? */
- set_git_dir(real_path(gitdirenv));
+ set_git_dir(gitdirenv, 1);
if (chdir(worktree))
die_errno(_("cannot chdir to '%s'"), worktree);
strbuf_addch(cwd, '/');
@@ -775,7 +775,7 @@
}
/* cwd outside worktree */
- set_git_dir(gitdirenv);
+ set_git_dir(gitdirenv, 0);
free(gitfile);
return NULL;
}
@@ -804,7 +804,7 @@
/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
if (is_bare_repository_cfg > 0) {
- set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
+ set_git_dir(gitdir, (offset != cwd->len));
if (chdir(cwd->buf))
die_errno(_("cannot come back to cwd"));
return NULL;
@@ -813,7 +813,7 @@
/* #0, #1, #5, #8, #9, #12, #13 */
set_git_work_tree(".");
if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
- set_git_dir(gitdir);
+ set_git_dir(gitdir, 0);
inside_git_dir = 0;
inside_work_tree = 1;
if (offset >= cwd->len)
@@ -856,10 +856,10 @@
die_errno(_("cannot come back to cwd"));
root_len = offset_1st_component(cwd->buf);
strbuf_setlen(cwd, offset > root_len ? offset : root_len);
- set_git_dir(cwd->buf);
+ set_git_dir(cwd->buf, 0);
}
else
- set_git_dir(".");
+ set_git_dir(".", 0);
return NULL;
}
