Avoid regexp overflow in mm-decode-content-transfer-encoding

* lisp/gnus/mm-bodies.el (mm-decode-content-transfer-encoding):
The base64 may be huge, so avoid backtracking (bug#55195).
This commit is contained in:
Lars Ingebrigtsen 2022-04-30 19:14:35 +02:00
parent 0ea0aa255c
commit d90f54db22

View file

@ -191,18 +191,17 @@ If TYPE is `text/plain' CRLF->LF translation may occur."
((eq encoding 'base64)
(base64-decode-region
(point-min)
;; Some mailers insert whitespace
;; junk at the end which
;; base64-decode-region dislikes.
;; Also remove possible junk which could
;; have been added by mailing list software.
(save-excursion
;; Some mailers insert whitespace junk at the end which
;; base64-decode-region dislikes.
(goto-char (point-min))
(while (re-search-forward "^[\t ]*\r?\n" nil t)
(delete-region (match-beginning 0) (match-end 0)))
;; Also ignore junk which could have been added by
;; mailing list software by finding the final line with
;; base64 text.
(goto-char (point-max))
(when (re-search-backward "^[\t ]*[A-Za-z0-9+/]+=*[\t ]*$"
nil t)
(when (re-search-backward "[A-Za-z0-9+/]{3,3}=?[\t ]*$" nil t)
(forward-line))
(point))))
((memq encoding '(nil 7bit 8bit binary))