From 0422433f4722e6e692b0c84342e048feff344e80 Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Thu, 2 Jul 2015 14:51:29 -0500
Subject: [PATCH] PJSIP XML, XPIDF: Fix buffer size overwrite memory corruption
error.
When res_pjsip body generator modules were generating XML or XPIDF
response bodies, there was a chance that the generated body would be the
exact size of the supplied buffer. Adding the nul string terminator would
then write beyond the end of the buffer and potentially corrupt memory.
* Fix MALLOC_DEBUG high fence violations caused by adding a nul string
terminator on the end of a buffer for XML or XPIDF response bodies.
* Made calls to pj_xml_print() safer if the XML prolog is requested. Due
to a bug in pjproject, the return value could be -1 _or_
AST_PJSIP_XML_PROLOG_LEN if the supplied buffer is not large enough.
* Updated the doxygen comment of AST_PJSIP_XML_PROLOG_LEN to describe the
return value of pj_xml_print() when the supplied buffer is not large
enough.
ASTERISK-25168
Reported by: Carl Fortin
Change-Id: Id70e1d373a6a2b2bd9e678b5cbc5e55b308981de
---
include/asterisk/res_pjsip_presence_xml.h | 9 +++++----
res/res_pjsip_dialog_info_body_generator.c | 9 ++++-----
res/res_pjsip_pidf_body_generator.c | 11 +++++------
res/res_pjsip_pubsub.c | 2 +-
res/res_pjsip_xpidf_body_generator.c | 9 ++++-----
5 files changed, 19 insertions(+), 21 deletions(-)
diff --git a/include/asterisk/res_pjsip_presence_xml.h b/include/asterisk/res_pjsip_presence_xml.h
index add5f89189..deed0901e4 100644
--- a/include/asterisk/res_pjsip_presence_xml.h
+++ b/include/asterisk/res_pjsip_presence_xml.h
@@ -17,14 +17,15 @@
*/
/*!
- * \brief The length of the XML prolog when printing
- * presence or other XML in PJSIP.
+ * \brief Length of the XML prolog when printing presence or other XML in PJSIP.
*
* When calling any variant of pj_xml_print(), the documentation
* claims that it will return -1 if the provided buffer is not
* large enough. However, if the XML prolog is requested to be
- * printed, then the length of the XML prolog is returned upon
- * failure instead of -1.
+ * printed and the buffer is not large enough, then it will
+ * return -1 only if the buffer is not large enough to hold the
+ * XML prolog or return the length of the XML prolog on failure
+ * instead of -1.
*
* This constant is useful to check against when trying to determine
* if printing XML succeeded or failed.
diff --git a/res/res_pjsip_dialog_info_body_generator.c b/res/res_pjsip_dialog_info_body_generator.c
index d9725f4c53..48ac60f98a 100644
--- a/res/res_pjsip_dialog_info_body_generator.c
+++ b/res/res_pjsip_dialog_info_body_generator.c
@@ -163,14 +163,13 @@ static void dialog_info_to_string(void *body, struct ast_str **str)
int size;
do {
- size = pj_xml_print(dialog_info, ast_str_buffer(*str), ast_str_size(*str), PJ_TRUE);
- if (size == AST_PJSIP_XML_PROLOG_LEN) {
+ size = pj_xml_print(dialog_info, ast_str_buffer(*str), ast_str_size(*str) - 1, PJ_TRUE);
+ if (size <= AST_PJSIP_XML_PROLOG_LEN) {
ast_str_make_space(str, ast_str_size(*str) * 2);
++growths;
}
- } while (size == AST_PJSIP_XML_PROLOG_LEN && growths < MAX_STRING_GROWTHS);
-
- if (size == AST_PJSIP_XML_PROLOG_LEN) {
+ } while (size <= AST_PJSIP_XML_PROLOG_LEN && growths < MAX_STRING_GROWTHS);
+ if (size <= AST_PJSIP_XML_PROLOG_LEN) {
ast_log(LOG_WARNING, "dialog-info+xml body text too large\n");
return;
}
diff --git a/res/res_pjsip_pidf_body_generator.c b/res/res_pjsip_pidf_body_generator.c
index ef0cce599a..d3be8c131f 100644
--- a/res/res_pjsip_pidf_body_generator.c
+++ b/res/res_pjsip_pidf_body_generator.c
@@ -84,19 +84,18 @@ static int pidf_generate_body_content(void *body, void *data)
static void pidf_to_string(void *body, struct ast_str **str)
{
- int size;
- int growths = 0;
pjpidf_pres *pres = body;
+ int growths = 0;
+ int size;
do {
size = pjpidf_print(pres, ast_str_buffer(*str), ast_str_size(*str) - 1);
- if (size == AST_PJSIP_XML_PROLOG_LEN) {
+ if (size <= AST_PJSIP_XML_PROLOG_LEN) {
ast_str_make_space(str, ast_str_size(*str) * 2);
++growths;
}
- } while (size == AST_PJSIP_XML_PROLOG_LEN && growths < MAX_STRING_GROWTHS);
-
- if (size == AST_PJSIP_XML_PROLOG_LEN) {
+ } while (size <= AST_PJSIP_XML_PROLOG_LEN && growths < MAX_STRING_GROWTHS);
+ if (size <= AST_PJSIP_XML_PROLOG_LEN) {
ast_log(LOG_WARNING, "PIDF body text too large\n");
return;
}
diff --git a/res/res_pjsip_pubsub.c b/res/res_pjsip_pubsub.c
index c00bc76ee6..650f5c5c8a 100644
--- a/res/res_pjsip_pubsub.c
+++ b/res/res_pjsip_pubsub.c
@@ -1769,7 +1769,7 @@ static int rlmi_print_body(struct pjsip_msg_body *msg_body, char *buf, pj_size_t
pj_xml_node *rlmi = msg_body->data;
num_printed = pj_xml_print(rlmi, buf, size, PJ_TRUE);
- if (num_printed == AST_PJSIP_XML_PROLOG_LEN) {
+ if (num_printed <= AST_PJSIP_XML_PROLOG_LEN) {
return -1;
}
diff --git a/res/res_pjsip_xpidf_body_generator.c b/res/res_pjsip_xpidf_body_generator.c
index 43cb1e78bc..298235cbce 100644
--- a/res/res_pjsip_xpidf_body_generator.c
+++ b/res/res_pjsip_xpidf_body_generator.c
@@ -106,14 +106,13 @@ static void xpidf_to_string(void *body, struct ast_str **str)
int size;
do {
- size = pjxpidf_print(pres, ast_str_buffer(*str), ast_str_size(*str));
- if (size == AST_PJSIP_XML_PROLOG_LEN) {
+ size = pjxpidf_print(pres, ast_str_buffer(*str), ast_str_size(*str) - 1);
+ if (size <= AST_PJSIP_XML_PROLOG_LEN) {
ast_str_make_space(str, ast_str_size(*str) * 2);
++growths;
}
- } while (size == AST_PJSIP_XML_PROLOG_LEN && growths < MAX_STRING_GROWTHS);
-
- if (size == AST_PJSIP_XML_PROLOG_LEN) {
+ } while (size <= AST_PJSIP_XML_PROLOG_LEN && growths < MAX_STRING_GROWTHS);
+ if (size <= AST_PJSIP_XML_PROLOG_LEN) {
ast_log(LOG_WARNING, "XPIDF body text too large\n");
return;
}
--
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