From ebe46ba82340cea8f030e0c0b3bb89aabad83674 Mon Sep 17 00:00:00 2001 Message-ID: From: Nick Wellnhofer Date: Tue, 27 May 2025 12:53:17 +0200 Subject: [PATCH] tree: Fix integer overflow in xmlBuildQName This issue affects memory safety and might receive a CVE ID later. Fixes #926. (cherry picked from commit acbbeef9f5dcdcc901c5f3fa14d583ef8cfd22f0) --- tree.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/tree.c b/tree.c index f097cf87..76112e22 100644 --- a/tree.c +++ b/tree.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #ifdef LIBXML_ZLIB_ENABLED @@ -167,10 +168,10 @@ xmlGetParameterEntityFromDtd(const xmlDtd *dtd, const xmlChar *name) { xmlChar * xmlBuildQName(const xmlChar *ncname, const xmlChar *prefix, xmlChar *memory, int len) { - int lenn, lenp; + size_t lenn, lenp; xmlChar *ret; - if (ncname == NULL) return(NULL); + if ((ncname == NULL) || (len < 0)) return(NULL); if (prefix == NULL) return((xmlChar *) ncname); #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION @@ -181,8 +182,10 @@ xmlBuildQName(const xmlChar *ncname, const xmlChar *prefix, lenn = strlen((char *) ncname); lenp = strlen((char *) prefix); + if (lenn >= SIZE_MAX - lenp - 1) + return(NULL); - if ((memory == NULL) || (len < lenn + lenp + 2)) { + if ((memory == NULL) || ((size_t) len < lenn + lenp + 2)) { ret = (xmlChar *) xmlMallocAtomic(lenn + lenp + 2); if (ret == NULL) return(NULL); base-commit: 3a1c25f5e7bbf8180690cf5c4c5a9fc1caf55c62 -- 2.50.0