From 9d626dffc6ba62c0d7a1a5c712f576ed8684fd66 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sun, 23 Feb 2020 16:19:42 -0800 Subject: Add 'nofollow' flag to set-file-modes etc. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This avoids some race conditions (Bug#39683). E.g., if some other program changes a file to a symlink between the time Emacs creates the file and the time it changes the file’s permissions, using the new flag prevents Emacs from inadvertently changing the permissions of a victim in some completely unrelated directory. * admin/merge-gnulib (GNULIB_MODULES): Add fchmodat. * doc/lispref/files.texi (Testing Accessibility, Changing Files): * doc/lispref/os.texi (File Notifications): * etc/NEWS: Adjust documentation accordingly. * lib/chmodat.c, lib/fchmodat.c, lib/lchmod.c, m4/fchmodat.m4: * m4/lchmod.m4: New files, copied from Gnulib. * lib/gnulib.mk.in: Regenerate. * lisp/dired-aux.el (dired-do-chmod): * lisp/doc-view.el (doc-view-make-safe-dir): * lisp/emacs-lisp/autoload.el (autoload--save-buffer): * lisp/emacs-lisp/bytecomp.el (byte-compile-file): * lisp/eshell/em-pred.el (eshell-pred-file-mode): * lisp/files.el (backup-buffer-copy, copy-directory): * lisp/gnus/mail-source.el (mail-source-movemail): * lisp/gnus/mm-decode.el (mm-display-external): * lisp/gnus/nnmail.el (nnmail-write-region): * lisp/net/tramp-adb.el (tramp-adb-handle-file-local-copy) (tramp-adb-handle-write-region): * lisp/net/tramp-sh.el (tramp-do-copy-or-rename-file-directly): * lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-write-region): * lisp/net/tramp.el (tramp-handle-write-region) (tramp-make-tramp-temp-file): * lisp/server.el (server-ensure-safe-dir): * lisp/url/url-util.el (url-make-private-file): When getting or setting file modes, avoid following symbolic links when the file is not supposed to be a symbolic link. * lisp/doc-view.el (doc-view-make-safe-dir): Omit no-longer-needed separate symlink test. * lisp/gnus/gnus-util.el (gnus-set-file-modes): * lisp/net/tramp.el (tramp-handle-file-modes): * lisp/net/tramp-gvfs.el (tramp-gvfs-handle-set-file-modes): * src/fileio.c (symlink_nofollow_flag): New function. (Ffile_modes, Fset_file_modes): Support an optional FLAG arg. All C callers changed. * lisp/net/ange-ftp.el (ange-ftp-set-file-modes): * lisp/net/tramp-adb.el (tramp-adb-handle-set-file-modes): * lisp/net/tramp-sh.el (tramp-sh-handle-set-file-modes): * lisp/net/tramp-smb.el (tramp-smb-handle-set-file-modes): * lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-set-file-modes): Accept an optional FLAG arg that is currently ignored, and add a FIXME comment for it. * m4/gnulib-comp.m4: Regenerate. --- lisp/server.el | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lisp/server.el') diff --git a/lisp/server.el b/lisp/server.el index e6d8b1783c9..18612181477 100644 --- a/lisp/server.el +++ b/lisp/server.el @@ -563,7 +563,7 @@ See variable `server-auth-dir' for details." (format "it is not owned by you (owner = %s (%d))" (user-full-name uid) uid)) (w32 nil) ; on NTFS? - ((let ((modes (file-modes dir))) + ((let ((modes (file-modes dir 'nofollow))) (unless (zerop (logand (or modes 0) #o077)) (format "it is accessible by others (%03o)" modes)))) (t nil)))) -- cgit v1.2.3