[Asterisk-code-review] Fix unsafe uses of ast context pointers. (asterisk[13])
Corey Farrell
asteriskteam at digium.com
Mon Jun 8 10:25:40 CDT 2015
Corey Farrell has uploaded a new change for review.
https://gerrit.asterisk.org/603
Change subject: Fix unsafe uses of ast_context pointers.
......................................................................
Fix unsafe uses of ast_context pointers.
Although ast_context_find, ast_context_find_or_create and
ast_context_destroy perform locking of the contexts table,
any context pointer can become invalid at any time that the
contexts table is unlocked. This change adds locking around
all complete operations involving these functions.
Places where ast_context_find was followed by ast_context_destroy
have been replaced with calls ast_context_destroy_by_name.
ASTERISK-25094 #close
Reported by: Corey Farrell
Change-Id: I1866b6787730c9c4f3f836b6133ffe9c820734fa
---
M apps/app_meetme.c
M channels/chan_iax2.c
M channels/chan_sip.c
M channels/chan_skinny.c
M include/asterisk/pbx.h
M main/pbx.c
M pbx/pbx_config.c
M tests/test_gosub.c
M tests/test_pbx.c
9 files changed, 69 insertions(+), 57 deletions(-)
git pull ssh://gerrit.asterisk.org:29418/asterisk refs/changes/03/603/1
diff --git a/apps/app_meetme.c b/apps/app_meetme.c
index 907770e..341014c 100644
--- a/apps/app_meetme.c
+++ b/apps/app_meetme.c
@@ -7539,14 +7539,13 @@
ao2_unlock(trunk);
if (!ast_strlen_zero(trunk->autocontext)) {
- struct ast_context *context;
- context = ast_context_find_or_create(NULL, NULL, trunk->autocontext, sla_registrar);
- if (!context) {
+ if (!ast_context_find_or_create(NULL, NULL, trunk->autocontext, sla_registrar)) {
ast_log(LOG_ERROR, "Failed to automatically find or create "
"context '%s' for SLA!\n", trunk->autocontext);
return -1;
}
- if (ast_add_extension2(context, 0 /* don't replace */, "s", 1,
+
+ if (ast_add_extension(trunk->autocontext, 0 /* don't replace */, "s", 1,
NULL, NULL, slatrunk_app, ast_strdup(trunk->name), ast_free_ptr, sla_registrar)) {
ast_log(LOG_ERROR, "Failed to automatically create extension "
"for trunk '%s'!\n", trunk->name);
@@ -7715,17 +7714,16 @@
ao2_unlock(station);
if (!ast_strlen_zero(station->autocontext)) {
- struct ast_context *context;
struct sla_trunk_ref *trunk_ref;
- context = ast_context_find_or_create(NULL, NULL, station->autocontext, sla_registrar);
- if (!context) {
+
+ if (!ast_context_find_or_create(NULL, NULL, station->autocontext, sla_registrar)) {
ast_log(LOG_ERROR, "Failed to automatically find or create "
"context '%s' for SLA!\n", station->autocontext);
return -1;
}
/* The extension for when the handset goes off-hook.
* exten => station1,1,SLAStation(station1) */
- if (ast_add_extension2(context, 0 /* don't replace */, station->name, 1,
+ if (ast_add_extension(station->autocontext, 0 /* don't replace */, station->name, 1,
NULL, NULL, slastation_app, ast_strdup(station->name), ast_free_ptr, sla_registrar)) {
ast_log(LOG_ERROR, "Failed to automatically create extension "
"for trunk '%s'!\n", station->name);
@@ -7738,7 +7736,7 @@
snprintf(hint, sizeof(hint), "SLA:%s", exten);
/* Extension for this line button
* exten => station1_line1,1,SLAStation(station1_line1) */
- if (ast_add_extension2(context, 0 /* don't replace */, exten, 1,
+ if (ast_add_extension(station->autocontext, 0 /* don't replace */, exten, 1,
NULL, NULL, slastation_app, ast_strdup(exten), ast_free_ptr, sla_registrar)) {
ast_log(LOG_ERROR, "Failed to automatically create extension "
"for trunk '%s'!\n", station->name);
@@ -7746,7 +7744,7 @@
}
/* Hint for this line button
* exten => station1_line1,hint,SLA:station1_line1 */
- if (ast_add_extension2(context, 0 /* don't replace */, exten, PRIORITY_HINT,
+ if (ast_add_extension(station->autocontext, 0 /* don't replace */, exten, PRIORITY_HINT,
NULL, NULL, hint, NULL, NULL, sla_registrar)) {
ast_log(LOG_ERROR, "Failed to automatically create hint "
"for trunk '%s'!\n", station->name);
diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index dc30d9f..6e8e9e4 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -14636,7 +14636,6 @@
static int __unload_module(void)
{
- struct ast_context *con;
int x;
network_change_stasis_unsubscribe();
@@ -14713,9 +14712,7 @@
sched = NULL;
ao2_ref(peercnts, -1);
- con = ast_context_find(regcontext);
- if (con)
- ast_context_destroy(con, "IAX2");
+ ast_context_destroy_by_name(regcontext, "IAX2");
ast_unload_realtime("iaxpeers");
ao2_ref(iax2_tech.capabilities, -1);
diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index b1fbd6e..5be0200 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -19750,8 +19750,7 @@
}
}
- if (stalecontext)
- ast_context_destroy(ast_context_find(stalecontext), "SIP");
+ ast_context_destroy_by_name(stalecontext, "SIP");
}
}
@@ -34540,7 +34539,6 @@
{
struct sip_pvt *p;
struct sip_threadinfo *th;
- struct ast_context *con;
struct ao2_iterator i;
int wait_count;
@@ -34718,10 +34716,7 @@
close(sipsock);
io_context_destroy(io);
ast_sched_context_destroy(sched);
- con = ast_context_find(used_context);
- if (con) {
- ast_context_destroy(con, "SIP");
- }
+ ast_context_destroy_by_name(used_context, "SIP");
ast_unload_realtime("sipregs");
ast_unload_realtime("sippeers");
ast_cc_monitor_unregister(&sip_cc_monitor_callbacks);
diff --git a/channels/chan_skinny.c b/channels/chan_skinny.c
index be9f9b6..3d2d2e8 100644
--- a/channels/chan_skinny.c
+++ b/channels/chan_skinny.c
@@ -2198,8 +2198,7 @@
}
}
- if (stalecontext)
- ast_context_destroy(ast_context_find(stalecontext), "Skinny");
+ ast_context_destroy_by_name(stalecontext, "Skinny");
}
}
@@ -8710,7 +8709,6 @@
struct skinny_device *d;
struct skinny_line *l;
struct skinny_subchannel *sub;
- struct ast_context *con;
pthread_t tempthread;
ast_rtp_glue_unregister(&skinny_rtp_glue);
@@ -8771,9 +8769,7 @@
ast_sched_context_destroy(sched);
}
- con = ast_context_find(used_context);
- if (con)
- ast_context_destroy(con, "Skinny");
+ ast_context_destroy_by_name(used_context, "Skinny");
ao2_ref(default_cap, -1);
return 0;
diff --git a/include/asterisk/pbx.h b/include/asterisk/pbx.h
index 795af05..5997458 100644
--- a/include/asterisk/pbx.h
+++ b/include/asterisk/pbx.h
@@ -300,7 +300,21 @@
void ast_merge_contexts_and_delete(struct ast_context **extcontexts, struct ast_hashtab *exttable, const char *registrar);
/*!
- * \brief Destroy a context (matches the specified context (or ANY context if NULL)
+ * \brief Destroy a context by name
+ *
+ * \param context Name of the context to destroy
+ * \param registrar who registered it
+ *
+ * You can optionally leave out the registrar parameter. It will find it
+ * based on the context name.
+ *
+ * \retval -1 context not found
+ * \retval 0 Success
+ */
+int ast_context_destroy_by_name(const char *context, const char *registrar);
+
+/*!
+ * \brief Destroy a context (matches the specified context or ANY context if NULL)
*
* \param con context to destroy
* \param registrar who registered it
diff --git a/main/pbx.c b/main/pbx.c
index 2be01b2..7686b4b 100644
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -8742,9 +8742,9 @@
ast_rdlock_contexts();
local_contexts = &contexts;
tmp = ast_hashtab_lookup(contexts_table, &search);
- ast_unlock_contexts();
if (tmp) {
tmp->refcount++;
+ ast_unlock_contexts();
return tmp;
}
} else { /* local contexts just in a linked list; search there for the new context; slow, linear search, but not frequent */
@@ -8768,11 +8768,13 @@
tmp->refcount = 1;
} else {
ast_log(LOG_ERROR, "Danger! We failed to allocate a context for %s!\n", name);
+ if (!extcontexts) {
+ ast_unlock_contexts();
+ }
return NULL;
}
if (!extcontexts) {
- ast_wrlock_contexts();
tmp->next = *local_contexts;
*local_contexts = tmp;
ast_hashtab_insert_safe(contexts_table, tmp); /*put this context into the tree */
@@ -9671,18 +9673,24 @@
int ast_ignore_pattern(const char *context, const char *pattern)
{
- struct ast_context *con = ast_context_find(context);
+ int ret = 0;
+ struct ast_context *con;
+ ast_rdlock_contexts();
+ con = ast_context_find(context);
if (con) {
struct ast_ignorepat *pat;
for (pat = con->ignorepats; pat; pat = pat->next) {
- if (ast_extension_match(pat->pattern, pattern))
- return 1;
+ if (ast_extension_match(pat->pattern, pattern)) {
+ ret = 1;
+ break;
+ }
}
}
+ ast_unlock_contexts();
- return 0;
+ return ret;
}
/*
@@ -10890,6 +10898,22 @@
}
}
+int ast_context_destroy_by_name(const char *context, const char *registrar)
+{
+ struct ast_context *con;
+ int ret = -1;
+
+ ast_wrlock_contexts();
+ con = ast_context_find(context);
+ if (con) {
+ ast_context_destroy(con, registrar);
+ ret = 0;
+ }
+ ast_unlock_contexts();
+
+ return ret;
+}
+
void ast_context_destroy(struct ast_context *con, const char *registrar)
{
ast_wrlock_contexts();
diff --git a/pbx/pbx_config.c b/pbx/pbx_config.c
index b036425..c4a0e6c 100644
--- a/pbx/pbx_config.c
+++ b/pbx/pbx_config.c
@@ -133,8 +133,6 @@
static char *handle_cli_dialplan_remove_context(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
- struct ast_context *con;
-
switch (cmd) {
case CLI_INIT:
e->command = "dialplan remove context";
@@ -150,16 +148,11 @@
return CLI_SHOWUSAGE;
}
- con = ast_context_find(a->argv[3]);
-
- if (!con) {
- ast_cli(a->fd, "There is no such context as '%s'\n",
- a->argv[3]);
- return CLI_SUCCESS;
+ if (ast_context_destroy_by_name(a->argv[3], NULL)) {
+ ast_cli(a->fd, "There is no such context as '%s'\n", a->argv[3]);
+ return CLI_SUCCESS;
} else {
- ast_context_destroy(con, registrar);
- ast_cli(a->fd, "Removing context '%s'\n",
- a->argv[3]);
+ ast_cli(a->fd, "Removed context '%s'\n", a->argv[3]);
return CLI_SUCCESS;
}
}
diff --git a/tests/test_gosub.c b/tests/test_gosub.c
index 604d8e3..05a3550 100644
--- a/tests/test_gosub.c
+++ b/tests/test_gosub.c
@@ -42,10 +42,10 @@
AST_TEST_DEFINE(test_gosub)
{
+#define CONTEXT_NAME "tests_test_gosub_virtual_context"
int res = AST_TEST_PASS, i;
struct ast_channel *chan;
struct ast_str *str;
- struct ast_context *con;
struct testplan {
const char *app;
const char *args;
@@ -119,14 +119,14 @@
}
/* Create our test dialplan */
- if (!(con = ast_context_find_or_create(NULL, NULL, "tests_test_gosub_virtual_context", "test_gosub"))) {
+ if (!ast_context_find_or_create(NULL, NULL, CONTEXT_NAME, "test_gosub")) {
ast_test_status_update(test, "Unable to create test dialplan context");
ast_free(str);
ast_channel_unref(chan);
return AST_TEST_FAIL;
}
- ast_add_extension2(con, 1, "s", 1, NULL, NULL, "NoOp", ast_strdup(""), ast_free_ptr, "test_gosub");
+ ast_add_extension(CONTEXT_NAME, 1, "s", 1, NULL, NULL, "NoOp", ast_strdup(""), ast_free_ptr, "test_gosub");
for (i = 0; i < ARRAY_LEN(testplan); i++) {
if (testplan[i].app == NULL) {
@@ -157,8 +157,8 @@
ast_free(str);
ast_channel_unref(chan);
- ast_context_remove_extension2(con, "s", 1, NULL, 0);
- ast_context_destroy(con, "test_gosub");
+ ast_context_remove_extension(CONTEXT_NAME, "s", 1, NULL);
+ ast_context_destroy(NULL, "test_gosub");
return res;
}
diff --git a/tests/test_pbx.c b/tests/test_pbx.c
index 5e2e232..bb5d8e8 100644
--- a/tests/test_pbx.c
+++ b/tests/test_pbx.c
@@ -198,7 +198,6 @@
*/
struct {
const char * context_string;
- struct ast_context *context;
} contexts[] = {
{ TEST_PATTERN, },
{ TEST_PATTERN_INCLUDE, },
@@ -267,7 +266,7 @@
*/
for (i = 0; i < ARRAY_LEN(contexts); ++i) {
- if (!(contexts[i].context = ast_context_find_or_create(NULL, NULL, contexts[i].context_string, registrar))) {
+ if (!ast_context_find_or_create(NULL, NULL, contexts[i].context_string, registrar)) {
ast_test_status_update(test, "Failed to create context %s\n", contexts[i].context_string);
res = AST_TEST_FAIL;
goto cleanup;
@@ -319,11 +318,7 @@
}
cleanup:
- for (i = 0; i < ARRAY_LEN(contexts); ++i) {
- if (contexts[i].context) {
- ast_context_destroy(contexts[i].context, registrar);
- }
- }
+ ast_context_destroy(NULL, registrar);
return res;
}
--
To view, visit https://gerrit.asterisk.org/603
To unsubscribe, visit https://gerrit.asterisk.org/settings
Gerrit-MessageType: newchange
Gerrit-Change-Id: I1866b6787730c9c4f3f836b6133ffe9c820734fa
Gerrit-PatchSet: 1
Gerrit-Project: asterisk
Gerrit-Branch: 13
Gerrit-Owner: Corey Farrell <git at cfware.com>
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