From e77659a8c87272e5061738a31430d2111482c426 Mon Sep 17 00:00:00 2001 From: Remi Collet Date: Tue, 10 Jun 2014 14:02:36 +0200 Subject: [PATCH] Fixed Bug #67410 fileinfo: mconvert incorrect handling of truncated pascal string size Upstream https://github.com/file/file/commit/27a14bc7ba285a0a5ebfdb55e54001aa11932b08 --- ext/fileinfo/libmagic/softmagic.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/ext/fileinfo/libmagic/softmagic.c b/ext/fileinfo/libmagic/softmagic.c index 21fea6b..01e4977 100644 --- a/ext/fileinfo/libmagic/softmagic.c +++ b/ext/fileinfo/libmagic/softmagic.c @@ -881,10 +881,18 @@ mconvert(struct magic_set *ms, struct magic *m, int flip) return 1; } case FILE_PSTRING: { - char *ptr1 = p->s, *ptr2 = ptr1 + file_pstring_length_size(m); + size_t sz = file_pstring_length_size(m); + char *ptr1 = p->s, *ptr2 = ptr1 + sz; size_t len = file_pstring_get_length(m, ptr1); - if (len >= sizeof(p->s)) - len = sizeof(p->s) - 1; + if (len >= sizeof(p->s)) { + /* + * The size of the pascal string length (sz) + * is 1, 2, or 4. We need at least 1 byte for NUL + * termination, but we've already truncated the + * string by p->s, so we need to deduct sz. + */ + len = sizeof(p->s) - sz; + } while (len--) *ptr1++ = *ptr2++; *ptr1 = '\0'; -- 1.9.2