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authorJan Kara <jack@suse.cz>2018-04-12 17:22:23 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-24 09:34:17 +0200
commit8c72cf489860f43bc974de9ecbc594c567bbe49a (patch)
treeec9a850aa3aee68b1abfdf5073cd7f2e296de77d
parent22578e220a870d7e677839eab207185faec3144a (diff)
udf: Fix leak of UTF-16 surrogates into encoded strings
commit 44f06ba8297c7e9dfd0e49b40cbe119113cca094 upstream. OSTA UDF specification does not mention whether the CS0 charset in case of two bytes per character encoding should be treated in UTF-16 or UCS-2. The sample code in the standard does not treat UTF-16 surrogates in any special way but on systems such as Windows which work in UTF-16 internally, filenames would be treated as being in UTF-16 effectively. In Linux it is more difficult to handle characters outside of Base Multilingual plane (beyond 0xffff) as NLS framework works with 2-byte characters only. Just make sure we don't leak UTF-16 surrogates into the resulting string when loading names from the filesystem for now. CC: stable@vger.kernel.org # >= v4.6 Reported-by: Mingye Wang <arthur200126@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/udf/unicode.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
index 695389a4fc23..3a3be23689b3 100644
--- a/fs/udf/unicode.c
+++ b/fs/udf/unicode.c
@@ -28,6 +28,9 @@
#include "udf_sb.h"
+#define SURROGATE_MASK 0xfffff800
+#define SURROGATE_PAIR 0x0000d800
+
static int udf_uni2char_utf8(wchar_t uni,
unsigned char *out,
int boundlen)
@@ -37,6 +40,9 @@ static int udf_uni2char_utf8(wchar_t uni,
if (boundlen <= 0)
return -ENAMETOOLONG;
+ if ((uni & SURROGATE_MASK) == SURROGATE_PAIR)
+ return -EINVAL;
+
if (uni < 0x80) {
out[u_len++] = (unsigned char)uni;
} else if (uni < 0x800) {