~ chicken-core (chicken-5) 46cf1138c2f14c1b2d10ba6d89d79de776ce2170
commit 46cf1138c2f14c1b2d10ba6d89d79de776ce2170
Author: Peter Bex <peter@more-magic.net>
AuthorDate: Sun Jun 14 19:52:26 2015 +0200
Commit: Evan Hanson <evhan@foldling.org>
CommitDate: Mon Jun 15 09:08:23 2015 +1200
Fix potential buffer overrun error in string-translate*
string-translate* would scan from every position in the target string
for each source string in the map, even if that would mean scanning
past the end. The out-of-bounds read would be limited to the size of
the overlapping prefix in the trailing garbage beyond the string,
because memcmp will stop scanning as soon as there is a different
byte in either of the memory areas.
This also adds a few basic tests for string-translate*
Signed-off-by: Evan Hanson <evhan@foldling.org>
diff --git a/NEWS b/NEWS
index bf075198..cae9bd32 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,7 @@
potential select() buffer overrun.
- CVE-2014-9651: substring-index[-ci] no longer scans beyond string
boundaries.
+ - string-translate* no longer scans beyond string boundaries.
- Core libraries
- alist-ref from unit data-structures now gives an error when passed
diff --git a/data-structures.scm b/data-structures.scm
index b67065ee..5664d087 100644
--- a/data-structures.scm
+++ b/data-structures.scm
@@ -514,7 +514,7 @@
(define (string-translate* str smap)
(##sys#check-string str 'string-translate*)
(##sys#check-list smap 'string-translate*)
- (let ([len (##sys#size str)])
+ (let ((len (##sys#size str)))
(define (collect i from total fs)
(if (fx>= i len)
(##sys#fragments->string
@@ -523,15 +523,16 @@
(if (fx> i from)
(cons (##sys#substring str from i) fs)
fs) ) )
- (let loop ([smap smap])
+ (let loop ((smap smap))
(if (null? smap)
(collect (fx+ i 1) from (fx+ total 1) fs)
- (let* ([p (car smap)]
- [sm (car p)]
- [smlen (string-length sm)]
- [st (cdr p)] )
- (if (##core#inline "C_substring_compare" str sm i 0 smlen)
- (let ([i2 (fx+ i smlen)])
+ (let* ((p (car smap))
+ (sm (car p))
+ (smlen (string-length sm))
+ (st (cdr p)) )
+ (if (and (fx<= (fx+ i smlen) len)
+ (##core#inline "C_substring_compare" str sm i 0 smlen))
+ (let ((i2 (fx+ i smlen)))
(when (fx> i from)
(set! fs (cons (##sys#substring str from i) fs)) )
(collect
diff --git a/tests/data-structures-tests.scm b/tests/data-structures-tests.scm
index 51c25a9e..b5768074 100644
--- a/tests/data-structures-tests.scm
+++ b/tests/data-structures-tests.scm
@@ -57,6 +57,17 @@
(assert (< 0 (string-compare3-ci "foo\x00b" "foo\x00a")))
(assert (< 0 (string-compare3-ci "foo\x00b" "foo\x00A")))
+(assert (string=? "bde" (string-translate* "abcd"
+ '(("a" . "b")
+ ("b" . "")
+ ("c" . "d")
+ ("d" . "e")))))
+(assert (string=? "bc" (string-translate* "abc"
+ '(("ab" . "b")
+ ("bc" . "WRONG")))))
+(assert (string=? "x" (string-translate* "ab" '(("ab" . "x")))))
+(assert (string=? "xy" (string-translate* "xyz" '(("z" . "")))))
+
;; topological-sort
(assert (equal? '() (topological-sort '() eq?)))
Trap