From 17d950ae33c23f87692aa179bacedb6743f3188a Mon Sep 17 00:00:00 2001 From: Nick Wellnhofer Date: Tue, 27 May 2025 12:53:17 +0200 Subject: [PATCH] [CVE-2025-6021] tree: Fix integer overflow in xmlBuildQName Fixes #926. --- tree.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/tree.c b/tree.c index f097cf87..5bc95b8a 100644 --- a/tree.c +++ b/tree.c @@ -47,6 +47,10 @@ #include "private/error.h" #include "private/tree.h" +#ifndef SIZE_MAX + #define SIZE_MAX ((size_t)-1) +#endif + int __xmlRegisterCallbacks = 0; /************************************************************************ @@ -167,10 +171,10 @@ 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 +185,10 @@ 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); -- 2.49.1