[Asterisk-code-review] app macro: Prevent infinite loop in find matching priority. (asterisk[13])

[Jenkins2]

Jenkins2 has submitted this change and it was merged. ( https://gerrit.asterisk.org/8931 )

Change subject: app_macro: Prevent infinite loop in find_matching_priority.
......................................................................

app_macro: Prevent infinite loop in find_matching_priority.

Use AST_PBX_MAX_STACK to escape if we recurse 128 times.  This will
prevent crash if dialplan contains an include loop.  Log an error when
this occurs, at most one message per call to Macro() so we avoid logger
spam.

ASTERISK-26570 #close

Change-Id: I6c71b76998c31434391b150de055ae9a531e31da
---
M apps/app_macro.c
1 file changed, 16 insertions(+), 3 deletions(-)

Approvals:
  Joshua Colp: Looks good to me, but someone else must approve
  George Joseph: Looks good to me, approved
  Jenkins2: Approved for Submit



diff --git a/apps/app_macro.c b/apps/app_macro.c
index 5c50a9f..16d9ce2 100644
--- a/apps/app_macro.c
+++ b/apps/app_macro.c
@@ -38,6 +38,7 @@
 #include "asterisk/channel.h"
 #include "asterisk/pbx.h"
 #include "asterisk/module.h"
+#include "asterisk/extconf.h"
 #include "asterisk/config.h"
 #include "asterisk/utils.h"
 #include "asterisk/lock.h"
@@ -187,11 +188,20 @@
 	}
 }
 
-static struct ast_exten *find_matching_priority(struct ast_context *c, const char *exten, int priority, const char *callerid)
+static struct ast_exten *find_matching_priority(struct ast_context *c, const char *exten,
+	int priority, const char *callerid, int iter, int *had_error)
 {
 	struct ast_exten *e;
 	struct ast_include *i;
 	struct ast_context *c2;
+
+	if (iter >= AST_PBX_MAX_STACK) {
+		if (!(*had_error)) {
+			*had_error = 1;
+			ast_log(LOG_ERROR, "Potential infinite loop detected, will not recurse further.\n");
+		}
+		return NULL;
+	}
 
 	for (e=ast_walk_context_extensions(c, NULL); e; e=ast_walk_context_extensions(c, e)) {
 		if (ast_extension_match(ast_get_extension_name(e), exten)) {
@@ -213,7 +223,7 @@
 	for (i=ast_walk_context_includes(c, NULL); i; i=ast_walk_context_includes(c, i)) {
 		for (c2=ast_walk_contexts(NULL); c2; c2=ast_walk_contexts(c2)) {
 			if (!strcmp(ast_get_context_name(c2), ast_get_include_name(i))) {
-				e = find_matching_priority(c2, exten, priority, callerid);
+				e = find_matching_priority(c2, exten, priority, callerid, iter + 1, had_error);
 				if (e)
 					return e;
 			}
@@ -250,6 +260,7 @@
 	char *save_macro_offset;
 	int save_in_subroutine;
 	struct ast_datastore *macro_store = ast_channel_datastore_find(chan, &macro_ds_info, NULL);
+	int had_infinite_include_error = 0;
 
 	if (ast_strlen_zero(data)) {
 		ast_log(LOG_WARNING, "Macro() requires arguments. See \"core show application macro\" for help.\n");
@@ -418,7 +429,9 @@
 						ast_log(LOG_WARNING, "Unable to lock context?\n");
 					} else {
 						e = find_matching_priority(c, ast_channel_exten(chan), ast_channel_priority(chan),
-							S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL));
+							S_COR(ast_channel_caller(chan)->id.number.valid,
+							ast_channel_caller(chan)->id.number.str, NULL),
+							0, &had_infinite_include_error);
 						if (e) { /* This will only be undefined for pbx_realtime, which is majorly broken. */
 							ast_copy_string(runningapp, ast_get_extension_app(e), sizeof(runningapp));
 							ast_copy_string(runningdata, ast_get_extension_app_data(e), sizeof(runningdata));

-- 
To view, visit https://gerrit.asterisk.org/8931
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Gerrit-Project: asterisk
Gerrit-Branch: 13
Gerrit-MessageType: merged
Gerrit-Change-Id: I6c71b76998c31434391b150de055ae9a531e31da
Gerrit-Change-Number: 8931
Gerrit-PatchSet: 2
Gerrit-Owner: Corey Farrell <git at cfware.com>
Gerrit-Reviewer: George Joseph <gjoseph at digium.com>
Gerrit-Reviewer: Jenkins2
Gerrit-Reviewer: Joshua Colp <jcolp at digium.com>
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