+++ /dev/null
-From 22b1db9d46654afc6f0c28f90af8cdc84a199f41 Mon Sep 17 00:00:00 2001
-From: Martin Matuska <martin@matuska.org>
-Date: Thu, 21 Nov 2019 03:08:40 +0100
-Subject: [PATCH] Bugfix and optimize archive_wstring_append_from_mbs()
-
-The cal to mbrtowc() or mbtowc() should read up to mbs_length
-bytes and not wcs_length. This avoids out-of-bounds reads.
-
-mbrtowc() and mbtowc() return (size_t)-1 wit errno EILSEQ when
-they encounter an invalid multibyte character and (size_t)-2 when
-they they encounter an incomplete multibyte character. As we return
-failure and all our callers error out it makes no sense to continue
-parsing mbs.
-
-As we allocate `len` wchars at the beginning and each wchar has
-at least one byte, there will never be need to grow the buffer,
-so the code can be left out. On the other hand, we are always
-allocatng more memory than we need.
-
-As long as wcs_length == mbs_length == len we can omit wcs_length.
-We keep the old code commented if we decide to save memory and
-use autoexpanding wcs_length in the future.
-
-Fixes #1276
-
-Upstream-Status: Backport [https://github.com/libarchive/libarchive/commit/22b1db9d46654afc6f0c28f90af8cdc84a199f41]
-CVE: CVE-2019-19221
-Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
----
- libarchive/archive_string.c | 28 +++++++++++++++++-----------
- 1 file changed, 17 insertions(+), 11 deletions(-)
-
-diff --git a/libarchive/archive_string.c b/libarchive/archive_string.c
-index 979a418b6..bd39c96f1 100644
---- a/libarchive/archive_string.c
-+++ b/libarchive/archive_string.c
-@@ -591,7 +591,7 @@ archive_wstring_append_from_mbs(struct archive_wstring *dest,
- * No single byte will be more than one wide character,
- * so this length estimate will always be big enough.
- */
-- size_t wcs_length = len;
-+ // size_t wcs_length = len;
- size_t mbs_length = len;
- const char *mbs = p;
- wchar_t *wcs;
-@@ -600,7 +600,11 @@ archive_wstring_append_from_mbs(struct archive_wstring *dest,
-
- memset(&shift_state, 0, sizeof(shift_state));
- #endif
-- if (NULL == archive_wstring_ensure(dest, dest->length + wcs_length + 1))
-+ /*
-+ * As we decided to have wcs_length == mbs_length == len
-+ * we can use len here instead of wcs_length
-+ */
-+ if (NULL == archive_wstring_ensure(dest, dest->length + len + 1))
- return (-1);
- wcs = dest->s + dest->length;
- /*
-@@ -609,6 +613,12 @@ archive_wstring_append_from_mbs(struct archive_wstring *dest,
- * multi bytes.
- */
- while (*mbs && mbs_length > 0) {
-+ /*
-+ * The buffer we allocated is always big enough.
-+ * Keep this code path in a comment if we decide to choose
-+ * smaller wcs_length in the future
-+ */
-+/*
- if (wcs_length == 0) {
- dest->length = wcs - dest->s;
- dest->s[dest->length] = L'\0';
-@@ -618,24 +628,20 @@ archive_wstring_append_from_mbs(struct archive_wstring *dest,
- return (-1);
- wcs = dest->s + dest->length;
- }
-+*/
- #if HAVE_MBRTOWC
-- r = mbrtowc(wcs, mbs, wcs_length, &shift_state);
-+ r = mbrtowc(wcs, mbs, mbs_length, &shift_state);
- #else
-- r = mbtowc(wcs, mbs, wcs_length);
-+ r = mbtowc(wcs, mbs, mbs_length);
- #endif
- if (r == (size_t)-1 || r == (size_t)-2) {
- ret_val = -1;
-- if (errno == EILSEQ) {
-- ++mbs;
-- --mbs_length;
-- continue;
-- } else
-- break;
-+ break;
- }
- if (r == 0 || r > mbs_length)
- break;
- wcs++;
-- wcs_length--;
-+ // wcs_length--;
- mbs += r;
- mbs_length -= r;
- }
