From: Mark Michelson <mmichelson@digium.com>
Date: Wed, 17 Jun 2009 19:59:31 +0000 (+0000)
Subject: Change the datastore traversal in ast_do_masquerade to use a safe list traversal.
X-Git-Tag: 1.4.26~56
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=03909de70232c5b36dac5c2c43be0ef626e96e59;p=thirdparty%2Fasterisk.git

Change the datastore traversal in ast_do_masquerade to use a safe list traversal.

It is possible for datastore fixup functions to remove the datastore from the list
and free it. In particular, the queue_transfer_fixup in app_queue does this. While
I don't yet know of this causing any crashes, it certainly could.

Found while discussing a separate issue with Brian Degenhardt.



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@201450 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/main/channel.c b/main/channel.c
index 0add3a8247..98e9c3f37f 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -3888,10 +3888,14 @@ int ast_do_masquerade(struct ast_channel *original)
 	/* Move data stores over */
 	if (AST_LIST_FIRST(&clone->datastores)) {
 		struct ast_datastore *ds;
-		AST_LIST_TRAVERSE(&clone->datastores, ds, entry) {
+		/* We use a safe traversal here because some fixup routines actually
+		 * remove the datastore from the list and free them.
+		 */
+		AST_LIST_TRAVERSE_SAFE_BEGIN(&clone->datastores, ds, entry) {
 			if (ds->info->chan_fixup)
 				ds->info->chan_fixup(ds->data, clone, original);
 		}
+		AST_LIST_TRAVERSE_SAFE_END;
 		AST_LIST_APPEND_LIST(&original->datastores, &clone->datastores, entry);
 	}