httpd/SOURCES/httpd-2.4.37-CVE-2022-22721...

104 lines
4.0 KiB
Diff

diff --git a/docs/manual/mod/core.html.en b/docs/manual/mod/core.html.en
index 20d1e5a..e1ec8d0 100644
--- a/docs/manual/mod/core.html.en
+++ b/docs/manual/mod/core.html.en
@@ -2935,12 +2935,19 @@ from the client</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
</table>
- <p>Limit (in bytes) on maximum size of an XML-based request
- body. A value of <code>0</code> will disable any checking.</p>
+ <p>Limit (in bytes) on the maximum size of an XML-based request
+ body. A value of <code>0</code> will apply a hard limit (depending on
+ 32bit vs 64bit system) allowing for XML escaping within the bounds of
+ the system addressable memory, but it exists for compatibility only
+ and is not recommended since it does not account for memory consumed
+ elsewhere or concurrent requests, which might result in an overall
+ system out-of-memory.
+ </p>
<p>Example:</p>
- <pre class="prettyprint lang-config">LimitXMLRequestBody 0</pre>
+ <pre class="prettyprint lang-config"># Limit of 1 MiB
+ LimitXMLRequestBody 1073741824</pre>
diff --git a/server/core.c b/server/core.c
index e32613d..8abfa65 100644
--- a/server/core.c
+++ b/server/core.c
@@ -70,6 +70,8 @@
/* LimitXMLRequestBody handling */
#define AP_LIMIT_UNSET ((long) -1)
#define AP_DEFAULT_LIMIT_XML_BODY ((apr_size_t)1000000)
+/* Hard limit for ap_escape_html2() */
+#define AP_MAX_LIMIT_XML_BODY ((apr_size_t)(APR_SIZE_MAX / 6 - 1))
#define AP_MIN_SENDFILE_BYTES (256)
@@ -3689,6 +3691,11 @@ static const char *set_limit_xml_req_body(cmd_parms *cmd, void *conf_,
if (conf->limit_xml_body < 0)
return "LimitXMLRequestBody requires a non-negative integer.";
+ /* zero is AP_MAX_LIMIT_XML_BODY (implicitly) */
+ if ((apr_size_t)conf->limit_xml_body > AP_MAX_LIMIT_XML_BODY)
+ return apr_psprintf(cmd->pool, "LimitXMLRequestBody must not exceed "
+ "%" APR_SIZE_T_FMT, AP_MAX_LIMIT_XML_BODY);
+
return NULL;
}
@@ -3777,6 +3784,8 @@ AP_DECLARE(apr_size_t) ap_get_limit_xml_body(const request_rec *r)
conf = ap_get_core_module_config(r->per_dir_config);
if (conf->limit_xml_body == AP_LIMIT_UNSET)
return AP_DEFAULT_LIMIT_XML_BODY;
+ if (conf->limit_xml_body == 0)
+ return AP_MAX_LIMIT_XML_BODY;
return (apr_size_t)conf->limit_xml_body;
}
diff --git a/server/util.c b/server/util.c
index 2a5dd04..eefdafa 100644
--- a/server/util.c
+++ b/server/util.c
@@ -2037,11 +2037,14 @@ AP_DECLARE(char *) ap_escape_urlencoded(apr_pool_t *p, const char *buffer)
AP_DECLARE(char *) ap_escape_html2(apr_pool_t *p, const char *s, int toasc)
{
- int i, j;
+ apr_size_t i, j;
char *x;
/* first, count the number of extra characters */
- for (i = 0, j = 0; s[i] != '\0'; i++)
+ for (i = 0, j = 0; s[i] != '\0'; i++) {
+ if (i + j > APR_SIZE_MAX - 6) {
+ abort();
+ }
if (s[i] == '<' || s[i] == '>')
j += 3;
else if (s[i] == '&')
@@ -2050,6 +2053,7 @@ AP_DECLARE(char *) ap_escape_html2(apr_pool_t *p, const char *s, int toasc)
j += 5;
else if (toasc && !apr_isascii(s[i]))
j += 5;
+ }
if (j == 0)
return apr_pstrmemdup(p, s, i);
diff --git a/server/util_xml.c b/server/util_xml.c
index 4845194..22806fa 100644
--- a/server/util_xml.c
+++ b/server/util_xml.c
@@ -85,7 +85,7 @@ AP_DECLARE(int) ap_xml_parse_input(request_rec * r, apr_xml_doc **pdoc)
}
total_read += len;
- if (limit_xml_body && total_read > limit_xml_body) {
+ if (total_read > limit_xml_body) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00539)
"XML request body is larger than the configured "
"limit of %lu", (unsigned long)limit_xml_body);