From 7afb666b26cfb17689e5da98bed610a417083f9d Mon Sep 17 00:00:00 2001 From: David King Date: Tue, 3 Jan 2023 09:57:28 +0000 Subject: [PATCH 1/2] Fix CVE-2022-40303 Adapted from https://gitlab.gnome.org/GNOME/libxml2/-/commit/c846986356fc149915a74972bf198abc266bc2c0 --- parser.c | 232 +++++++++++++++++++++++++++++-------------------------- 1 file changed, 121 insertions(+), 111 deletions(-) diff --git a/parser.c b/parser.c index 1c5e036e..e66e4196 100644 --- a/parser.c +++ b/parser.c @@ -108,6 +108,8 @@ static void xmlHaltParser(xmlParserCtxtPtr ctxt); * * ************************************************************************/ +#define XML_MAX_HUGE_LENGTH 1000000000 + #define XML_PARSER_BIG_ENTITY 1000 #define XML_PARSER_LOT_ENTITY 5000 @@ -532,7 +534,7 @@ xmlFatalErr(xmlParserCtxtPtr ctxt, xmlParserErrors error, const char *info) errmsg = "Malformed declaration expecting version"; break; case XML_ERR_NAME_TOO_LONG: - errmsg = "Name too long use XML_PARSE_HUGE option"; + errmsg = "Name too long"; break; #if 0 case: @@ -3150,6 +3152,9 @@ xmlParseNameComplex(xmlParserCtxtPtr ctxt) { int len = 0, l; int c; int count = 0; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_TEXT_LENGTH : + XML_MAX_NAME_LENGTH; #ifdef DEBUG nbParseNameComplex++; @@ -3241,13 +3246,13 @@ xmlParseNameComplex(xmlParserCtxtPtr ctxt) { if (ctxt->instate == XML_PARSER_EOF) return(NULL); } - len += l; + if (len <= INT_MAX - l) + len += l; NEXTL(l); c = CUR_CHAR(l); } } - if ((len > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if (len > maxLength) { xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "Name"); return(NULL); } @@ -3286,7 +3291,10 @@ const xmlChar * xmlParseName(xmlParserCtxtPtr ctxt) { const xmlChar *in; const xmlChar *ret; - int count = 0; + size_t count = 0; + size_t maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_TEXT_LENGTH : + XML_MAX_NAME_LENGTH; GROW; @@ -3310,8 +3318,7 @@ xmlParseName(xmlParserCtxtPtr ctxt) { in++; if ((*in > 0) && (*in < 0x80)) { count = in - ctxt->input->cur; - if ((count > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if (count > maxLength) { xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "Name"); return(NULL); } @@ -3333,6 +3340,9 @@ xmlParseNCNameComplex(xmlParserCtxtPtr ctxt) { int len = 0, l; int c; int count = 0; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_TEXT_LENGTH : + XML_MAX_NAME_LENGTH; size_t startPosition = 0; #ifdef DEBUG @@ -3353,17 +3363,13 @@ xmlParseNCNameComplex(xmlParserCtxtPtr ctxt) { while ((c != ' ') && (c != '>') && (c != '/') && /* test bigname.xml */ (xmlIsNameChar(ctxt, c) && (c != ':'))) { if (count++ > XML_PARSER_CHUNK_SIZE) { - if ((len > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName"); - return(NULL); - } count = 0; GROW; if (ctxt->instate == XML_PARSER_EOF) return(NULL); } - len += l; + if (len <= INT_MAX - l) + len += l; NEXTL(l); c = CUR_CHAR(l); if (c == 0) { @@ -3381,8 +3387,7 @@ xmlParseNCNameComplex(xmlParserCtxtPtr ctxt) { c = CUR_CHAR(l); } } - if ((len > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if (len > maxLength) { xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName"); return(NULL); } @@ -3408,7 +3413,10 @@ static const xmlChar * xmlParseNCName(xmlParserCtxtPtr ctxt) { const xmlChar *in, *e; const xmlChar *ret; - int count = 0; + size_t count = 0; + size_t maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_TEXT_LENGTH : + XML_MAX_NAME_LENGTH; #ifdef DEBUG nbParseNCName++; @@ -3433,8 +3441,7 @@ xmlParseNCName(xmlParserCtxtPtr ctxt) { goto complex; if ((*in > 0) && (*in < 0x80)) { count = in - ctxt->input->cur; - if ((count > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if (count > maxLength) { xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName"); return(NULL); } @@ -3517,6 +3524,9 @@ xmlParseStringName(xmlParserCtxtPtr ctxt, const xmlChar** str) { const xmlChar *cur = *str; int len = 0, l; int c; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_TEXT_LENGTH : + XML_MAX_NAME_LENGTH; #ifdef DEBUG nbParseStringName++; @@ -3552,12 +3562,6 @@ xmlParseStringName(xmlParserCtxtPtr ctxt, const xmlChar** str) { if (len + 10 > max) { xmlChar *tmp; - if ((len > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName"); - xmlFree(buffer); - return(NULL); - } max *= 2; tmp = (xmlChar *) xmlRealloc(buffer, max * sizeof(xmlChar)); @@ -3571,14 +3575,18 @@ xmlParseStringName(xmlParserCtxtPtr ctxt, const xmlChar** str) { COPY_BUF(l,buffer,len,c); cur += l; c = CUR_SCHAR(cur, l); + if (len > maxLength) { + xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName"); + xmlFree(buffer); + return(NULL); + } } buffer[len] = 0; *str = cur; return(buffer); } } - if ((len > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if (len > maxLength) { xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName"); return(NULL); } @@ -3605,6 +3613,9 @@ xmlParseNmtoken(xmlParserCtxtPtr ctxt) { int len = 0, l; int c; int count = 0; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_TEXT_LENGTH : + XML_MAX_NAME_LENGTH; #ifdef DEBUG nbParseNmToken++; @@ -3656,12 +3667,6 @@ xmlParseNmtoken(xmlParserCtxtPtr ctxt) { if (len + 10 > max) { xmlChar *tmp; - if ((max > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NmToken"); - xmlFree(buffer); - return(NULL); - } max *= 2; tmp = (xmlChar *) xmlRealloc(buffer, max * sizeof(xmlChar)); @@ -3675,6 +3680,11 @@ xmlParseNmtoken(xmlParserCtxtPtr ctxt) { COPY_BUF(l,buffer,len,c); NEXTL(l); c = CUR_CHAR(l); + if (len > maxLength) { + xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NmToken"); + xmlFree(buffer); + return(NULL); + } } buffer[len] = 0; return(buffer); @@ -3682,8 +3692,7 @@ xmlParseNmtoken(xmlParserCtxtPtr ctxt) { } if (len == 0) return(NULL); - if ((len > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if (len > maxLength) { xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NmToken"); return(NULL); } @@ -3709,6 +3718,9 @@ xmlParseEntityValue(xmlParserCtxtPtr ctxt, xmlChar **orig) { int len = 0; int size = XML_PARSER_BUFFER_SIZE; int c, l; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_HUGE_LENGTH : + XML_MAX_TEXT_LENGTH; xmlChar stop; xmlChar *ret = NULL; const xmlChar *cur = NULL; @@ -3768,6 +3780,14 @@ xmlParseEntityValue(xmlParserCtxtPtr ctxt, xmlChar **orig) { GROW; c = CUR_CHAR(l); } + + if (len > maxLength) { + xmlFatalErrMsg(ctxt, XML_ERR_ENTITY_NOT_FINISHED, + "entity value too long\n"); + if (buf != NULL) + xmlFree(buf); + return(ret); + } } buf[len] = 0; if (ctxt->instate == XML_PARSER_EOF) @@ -3855,6 +3875,9 @@ xmlParseAttValueComplex(xmlParserCtxtPtr ctxt, int *attlen, int normalize) { xmlChar *rep = NULL; size_t len = 0; size_t buf_size = 0; + size_t maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_HUGE_LENGTH : + XML_MAX_TEXT_LENGTH; int c, l, in_space = 0; xmlChar *current = NULL; xmlEntityPtr ent; @@ -3886,16 +3909,6 @@ xmlParseAttValueComplex(xmlParserCtxtPtr ctxt, int *attlen, int normalize) { while (((NXT(0) != limit) && /* checked */ (IS_CHAR(c)) && (c != '<')) && (ctxt->instate != XML_PARSER_EOF)) { - /* - * Impose a reasonable limit on attribute size, unless XML_PARSE_HUGE - * special option is given - */ - if ((len > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, - "AttValue length too long\n"); - goto mem_error; - } if (c == 0) break; if (c == '&') { in_space = 0; @@ -4041,6 +4054,11 @@ xmlParseAttValueComplex(xmlParserCtxtPtr ctxt, int *attlen, int normalize) { } GROW; c = CUR_CHAR(l); + if (len > maxLength) { + xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, + "AttValue length too long\n"); + goto mem_error; + } } if (ctxt->instate == XML_PARSER_EOF) goto error; @@ -4062,16 +4080,6 @@ xmlParseAttValueComplex(xmlParserCtxtPtr ctxt, int *attlen, int normalize) { } else NEXT; - /* - * There we potentially risk an overflow, don't allow attribute value of - * length more than INT_MAX it is a very reasonnable assumption ! - */ - if (len >= INT_MAX) { - xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, - "AttValue length too long\n"); - goto mem_error; - } - if (attlen != NULL) *attlen = (int) len; return(buf); @@ -4142,6 +4150,9 @@ xmlParseSystemLiteral(xmlParserCtxtPtr ctxt) { int len = 0; int size = XML_PARSER_BUFFER_SIZE; int cur, l; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_TEXT_LENGTH : + XML_MAX_NAME_LENGTH; xmlChar stop; int state = ctxt->instate; int count = 0; @@ -4169,13 +4180,6 @@ xmlParseSystemLiteral(xmlParserCtxtPtr ctxt) { if (len + 5 >= size) { xmlChar *tmp; - if ((size > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "SystemLiteral"); - xmlFree(buf); - ctxt->instate = (xmlParserInputState) state; - return(NULL); - } size *= 2; tmp = (xmlChar *) xmlRealloc(buf, size * sizeof(xmlChar)); if (tmp == NULL) { @@ -4203,6 +4207,12 @@ xmlParseSystemLiteral(xmlParserCtxtPtr ctxt) { SHRINK; cur = CUR_CHAR(l); } + if (len > maxLength) { + xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "SystemLiteral"); + xmlFree(buf); + ctxt->instate = (xmlParserInputState) state; + return(NULL); + } } buf[len] = 0; ctxt->instate = (xmlParserInputState) state; @@ -4230,6 +4240,9 @@ xmlParsePubidLiteral(xmlParserCtxtPtr ctxt) { xmlChar *buf = NULL; int len = 0; int size = XML_PARSER_BUFFER_SIZE; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_TEXT_LENGTH : + XML_MAX_NAME_LENGTH; xmlChar cur; xmlChar stop; int count = 0; @@ -4257,12 +4270,6 @@ xmlParsePubidLiteral(xmlParserCtxtPtr ctxt) { if (len + 1 >= size) { xmlChar *tmp; - if ((size > XML_MAX_NAME_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "Public ID"); - xmlFree(buf); - return(NULL); - } size *= 2; tmp = (xmlChar *) xmlRealloc(buf, size * sizeof(xmlChar)); if (tmp == NULL) { @@ -4289,6 +4296,11 @@ xmlParsePubidLiteral(xmlParserCtxtPtr ctxt) { SHRINK; cur = CUR; } + if (len > maxLength) { + xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "Public ID"); + xmlFree(buf); + return(NULL); + } } buf[len] = 0; if (cur != stop) { @@ -4686,6 +4698,9 @@ xmlParseCommentComplex(xmlParserCtxtPtr ctxt, xmlChar *buf, int r, rl; int cur, l; size_t count = 0; + size_t maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_HUGE_LENGTH : + XML_MAX_TEXT_LENGTH; int inputid; inputid = ctxt->input->id; @@ -4731,13 +4746,6 @@ xmlParseCommentComplex(xmlParserCtxtPtr ctxt, xmlChar *buf, if ((r == '-') && (q == '-')) { xmlFatalErr(ctxt, XML_ERR_HYPHEN_IN_COMMENT, NULL); } - if ((len > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErrMsgStr(ctxt, XML_ERR_COMMENT_NOT_FINISHED, - "Comment too big found", NULL); - xmlFree (buf); - return; - } if (len + 5 >= size) { xmlChar *new_buf; size_t new_size; @@ -4774,6 +4782,13 @@ xmlParseCommentComplex(xmlParserCtxtPtr ctxt, xmlChar *buf, GROW; cur = CUR_CHAR(l); } + + if (len > maxLength) { + xmlFatalErrMsgStr(ctxt, XML_ERR_COMMENT_NOT_FINISHED, + "Comment too big found", NULL); + xmlFree (buf); + return; + } } buf[len] = 0; if (cur == 0) { @@ -4818,6 +4833,9 @@ xmlParseComment(xmlParserCtxtPtr ctxt) { xmlChar *buf = NULL; size_t size = XML_PARSER_BUFFER_SIZE; size_t len = 0; + size_t maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_HUGE_LENGTH : + XML_MAX_TEXT_LENGTH; xmlParserInputState state; const xmlChar *in; size_t nbchar = 0; @@ -4901,8 +4919,7 @@ get_more: buf[len] = 0; } } - if ((len > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if (len > maxLength) { xmlFatalErrMsgStr(ctxt, XML_ERR_COMMENT_NOT_FINISHED, "Comment too big found", NULL); xmlFree (buf); @@ -5098,6 +5115,9 @@ xmlParsePI(xmlParserCtxtPtr ctxt) { xmlChar *buf = NULL; size_t len = 0; size_t size = XML_PARSER_BUFFER_SIZE; + size_t maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_HUGE_LENGTH : + XML_MAX_TEXT_LENGTH; int cur, l; const xmlChar *target; xmlParserInputState state; @@ -5172,14 +5192,6 @@ xmlParsePI(xmlParserCtxtPtr ctxt) { return; } count = 0; - if ((len > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErrMsgStr(ctxt, XML_ERR_PI_NOT_FINISHED, - "PI %s too big found", target); - xmlFree(buf); - ctxt->instate = state; - return; - } } COPY_BUF(l,buf,len,cur); NEXTL(l); @@ -5189,15 +5201,14 @@ xmlParsePI(xmlParserCtxtPtr ctxt) { GROW; cur = CUR_CHAR(l); } + if (len > maxLength) { + xmlFatalErrMsgStr(ctxt, XML_ERR_PI_NOT_FINISHED, + "PI %s too big found", target); + xmlFree(buf); + ctxt->instate = state; + return; + } } - if ((len > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErrMsgStr(ctxt, XML_ERR_PI_NOT_FINISHED, - "PI %s too big found", target); - xmlFree(buf); - ctxt->instate = state; - return; - } buf[len] = 0; if (cur != '?') { xmlFatalErrMsgStr(ctxt, XML_ERR_PI_NOT_FINISHED, @@ -8851,6 +8862,9 @@ xmlParseAttValueInternal(xmlParserCtxtPtr ctxt, int *len, int *alloc, const xmlChar *in = NULL, *start, *end, *last; xmlChar *ret = NULL; int line, col; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_HUGE_LENGTH : + XML_MAX_TEXT_LENGTH; GROW; in = (xmlChar *) CUR_PTR; @@ -8906,8 +8920,7 @@ xmlParseAttValueInternal(xmlParserCtxtPtr ctxt, int *len, int *alloc, in = in + delta; } end = ctxt->input->end; - if (((in - start) > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if ((in - start) > maxLength) { xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, "AttValue length too long\n"); return(NULL); @@ -8929,8 +8942,7 @@ xmlParseAttValueInternal(xmlParserCtxtPtr ctxt, int *len, int *alloc, in = in + delta; } end = ctxt->input->end; - if (((in - start) > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if ((in - start) > maxLength) { xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, "AttValue length too long\n"); return(NULL); @@ -8963,16 +8975,14 @@ xmlParseAttValueInternal(xmlParserCtxtPtr ctxt, int *len, int *alloc, last = last + delta; } end = ctxt->input->end; - if (((in - start) > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if ((in - start) > maxLength) { xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, "AttValue length too long\n"); return(NULL); } } } - if (((in - start) > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if ((in - start) > maxLength) { xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, "AttValue length too long\n"); return(NULL); @@ -8994,8 +9004,7 @@ xmlParseAttValueInternal(xmlParserCtxtPtr ctxt, int *len, int *alloc, in = in + delta; } end = ctxt->input->end; - if (((in - start) > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if ((in - start) > maxLength) { xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, "AttValue length too long\n"); return(NULL); @@ -9003,8 +9012,7 @@ xmlParseAttValueInternal(xmlParserCtxtPtr ctxt, int *len, int *alloc, } } last = in; - if (((in - start) > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { + if ((in - start) > maxLength) { xmlFatalErrMsg(ctxt, XML_ERR_ATTRIBUTE_NOT_FINISHED, "AttValue length too long\n"); return(NULL); @@ -9711,6 +9719,9 @@ xmlParseCDSect(xmlParserCtxtPtr ctxt) { int s, sl; int cur, l; int count = 0; + int maxLength = (ctxt->options & XML_PARSE_HUGE) ? + XML_MAX_HUGE_LENGTH : + XML_MAX_TEXT_LENGTH; /* Check 2.6.0 was NXT(0) not RAW */ if (CMP9(CUR_PTR, '<', '!', '[', 'C', 'D', 'A', 'T', 'A', '[')) { @@ -9744,13 +9755,6 @@ xmlParseCDSect(xmlParserCtxtPtr ctxt) { if (len + 5 >= size) { xmlChar *tmp; - if ((size > XML_MAX_TEXT_LENGTH) && - ((ctxt->options & XML_PARSE_HUGE) == 0)) { - xmlFatalErrMsgStr(ctxt, XML_ERR_CDATA_NOT_FINISHED, - "CData section too big found", NULL); - xmlFree (buf); - return; - } tmp = (xmlChar *) xmlRealloc(buf, size * 2 * sizeof(xmlChar)); if (tmp == NULL) { xmlFree(buf); @@ -9776,6 +9780,12 @@ xmlParseCDSect(xmlParserCtxtPtr ctxt) { } NEXTL(l); cur = CUR_CHAR(l); + if (len > maxLength) { + xmlFatalErrMsg(ctxt, XML_ERR_CDATA_NOT_FINISHED, + "CData section too big found\n"); + xmlFree(buf); + return; + } } buf[len] = 0; ctxt->instate = XML_PARSER_CONTENT; -- 2.39.0