worktree: do not pass strbuf by value
write_worktree_linking_files() takes two struct strbuf parameters by value, even though it only reads path strings from them. Passing a strbuf by value is misleading and dangerous. The structure carries a pointer to its underlying character array; caller and callee end up sharing that storage. If the callee ever causes the strbuf to be reallocated, the caller's copy becomes a dangling pointer, which results in a double-free when the caller does strbuf_release(). The function only needs the string values, not the strbuf machinery. Switch it to take const char * and update all callers to pass .buf. Signed-off-by: Deveshi Dwivedi <deveshigurgaon@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Deveshi Dwivedi committed
Mar 11, 2026 at 17:33 UTC
4107c0bb3455905aeacdba3be09b20e62b310eaa
3 files changed
+13
-13
builtin/worktree.c
+1
-1
index bc2d0d645b..4035b1cb06 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -539,7 +539,7 @@ static int add_worktree(const char *path, const char *refname,
strbuf_reset(&sb);
strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
- write_worktree_linking_files(sb_git, sb, opts->relative_paths);
+ write_worktree_linking_files(sb_git.buf, sb.buf, opts->relative_paths);
strbuf_reset(&sb);
strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
write_file(sb.buf, "../..");
worktree.c
+11
-11
index 6e2f0f7828..7eba12c6ed 100644
--- a/worktree.c
+++ b/worktree.c
@@ -445,7 +445,7 @@ void update_worktree_location(struct worktree *wt, const char *path_,
strbuf_realpath(&path, path_, 1);
strbuf_addf(&dotgit, "%s/.git", path.buf);
if (fspathcmp(wt->path, path.buf)) {
- write_worktree_linking_files(dotgit, gitdir, use_relative_paths);
+ write_worktree_linking_files(dotgit.buf, gitdir.buf, use_relative_paths);
free(wt->path);
wt->path = strbuf_detach(&path, NULL);
@@ -684,7 +684,7 @@ static void repair_gitfile(struct worktree *wt,
if (repair) {
fn(0, wt->path, repair, cb_data);
- write_worktree_linking_files(dotgit, gitdir, use_relative_paths);
+ write_worktree_linking_files(dotgit.buf, gitdir.buf, use_relative_paths);
}
done:
@@ -742,7 +742,7 @@ void repair_worktree_after_gitdir_move(struct worktree *wt, const char *old_path
if (!file_exists(dotgit.buf))
goto done;
- write_worktree_linking_files(dotgit, gitdir, is_relative_path);
+ write_worktree_linking_files(dotgit.buf, gitdir.buf, is_relative_path);
done:
strbuf_release(&gitdir);
strbuf_release(&dotgit);
@@ -913,7 +913,7 @@ void repair_worktree_at_path(const char *path,
if (repair) {
fn(0, gitdir.buf, repair, cb_data);
- write_worktree_linking_files(dotgit, gitdir, use_relative_paths);
+ write_worktree_linking_files(dotgit.buf, gitdir.buf, use_relative_paths);
}
done:
free(dotgit_contents);
@@ -1087,17 +1087,17 @@ cleanup:
return res;
}
-void write_worktree_linking_files(struct strbuf dotgit, struct strbuf gitdir,
+void write_worktree_linking_files(const char *dotgit, const char *gitdir,
int use_relative_paths)
{
struct strbuf path = STRBUF_INIT;
struct strbuf repo = STRBUF_INIT;
struct strbuf tmp = STRBUF_INIT;
- strbuf_addbuf(&path, &dotgit);
+ strbuf_addstr(&path, dotgit);
strbuf_strip_suffix(&path, "/.git");
strbuf_realpath(&path, path.buf, 1);
- strbuf_addbuf(&repo, &gitdir);
+ strbuf_addstr(&repo, gitdir);
strbuf_strip_suffix(&repo, "/gitdir");
strbuf_realpath(&repo, repo.buf, 1);
@@ -1110,11 +1110,11 @@ void write_worktree_linking_files(struct strbuf dotgit, struct strbuf gitdir,
}
if (use_relative_paths) {
- write_file(gitdir.buf, "%s/.git", relative_path(path.buf, repo.buf, &tmp));
- write_file(dotgit.buf, "gitdir: %s", relative_path(repo.buf, path.buf, &tmp));
+ write_file(gitdir, "%s/.git", relative_path(path.buf, repo.buf, &tmp));
+ write_file(dotgit, "gitdir: %s", relative_path(repo.buf, path.buf, &tmp));
} else {
- write_file(gitdir.buf, "%s/.git", path.buf);
- write_file(dotgit.buf, "gitdir: %s", repo.buf);
+ write_file(gitdir, "%s/.git", path.buf);
+ write_file(dotgit, "gitdir: %s", repo.buf);
}
strbuf_release(&path);
worktree.h
+1
-1
index 06efe26b83..f4e46be385 100644
--- a/worktree.h
+++ b/worktree.h
@@ -240,7 +240,7 @@ int init_worktree_config(struct repository *r);
* dotgit: "/path/to/foo/.git"
* gitdir: "/path/to/repo/worktrees/foo/gitdir"
*/
-void write_worktree_linking_files(struct strbuf dotgit, struct strbuf gitdir,
+void write_worktree_linking_files(const char *dotgit, const char *gitdir,
int use_relative_paths);
#endif