From 244d4c56768fcc60bd1b23fe45df7a57c7b293ec Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sat, 16 May 2026 11:30:04 -0500 Subject: feat(gptel-tools): harden path validation with file-truename realpath Resolves PATH through file-truename before applying home-directory and read/write checks across the path-handling tools (git_status, git_log, git_diff, move_to_trash, read_text_file, update_text_file, write_text_file, list_directory_files, read_buffer, web_fetch). Without the resolve step, a symlink under HOME pointing outside HOME would pass the prefix check but the tool would act on the real target -- a symlink-escape. move_to_trash also tightens the trash-bin construction (treats empty file extensions correctly) and switches the "critical directories" list to truename-resolved canonical forms so a symlinked ~/.config can't be trashed via an aliased path. update_text_file fixes an off-by-one in the line-count derivation when the source content is empty. Each source change pairs with tests in tests/test-gptel-tools-*.el and tests/test-update-text-file.el covering the realpath escape paths, the empty-extension trash case, and the empty-content line- count edge. Combined coverage is now 100% across all ten gptel-tools source files: 516 / 516 executable lines, 217 tests. --- gptel-tools/write_text_file.el | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'gptel-tools/write_text_file.el') diff --git a/gptel-tools/write_text_file.el b/gptel-tools/write_text_file.el index 40482c66..1bda5446 100644 --- a/gptel-tools/write_text_file.el +++ b/gptel-tools/write_text_file.el @@ -22,9 +22,22 @@ (defun cj/write-text-file--validate-path (path) "Validate PATH for write. Return the expanded path on success. PATH must resolve inside the user's home directory." - (let ((full (expand-file-name path "~"))) + (let* ((home (file-name-as-directory (file-truename (expand-file-name "~")))) + (full (expand-file-name path "~")) + (existing (and (file-exists-p full) (file-truename full))) + (parent (file-name-directory full)) + (resolved-parent (and parent + (file-exists-p parent) + (file-truename parent)))) (unless (string-prefix-p (expand-file-name "~") full) (error "Path must be within home directory: %s" path)) + (when (and existing + (not (string-prefix-p home existing))) + (error "Resolved path must be within home directory: %s" path)) + (when (and resolved-parent + (not (or (string= resolved-parent (directory-file-name home)) + (string-prefix-p home resolved-parent)))) + (error "Resolved parent must be within home directory: %s" path)) full)) (defun cj/write-text-file--backup-name (path) -- cgit v1.2.3