[PATCH v3 1/2] worktree: do not pass strbuf by value
- From
Deveshi Dwivedi <deveshigurgaon@gmail.com>
- Date
- Mar 11, 2026, 17:33 UTC
- Message-ID
- <20260311173336.8395-2-deveshigurgaon@gmail.com>
- In-Reply-To
- <20260311173336.8395-1-deveshigurgaon@gmail.com>
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> --- builtin/worktree.c | 2 +- worktree.c | 22 +++++++++++----------- worktree.h | 2 +- 3 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/builtin/worktree.c b/builtin/worktree.c 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, "../.."); diff --git a/worktree.c b/worktree.c 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 @@ int init_worktree_config(struct repository *r) 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); diff --git a/worktree.h b/worktree.h 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
-- 2.52.0.230.gd8af7cadaa