Merged revisions 337974 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/10

................
  r337974 | rmudgett | 2011-09-26 14:35:23 -0500 (Mon, 26 Sep 2011) | 37 lines
  
  Merged revisions 337973 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.8
  
  ........
    r337973 | rmudgett | 2011-09-26 14:30:39 -0500 (Mon, 26 Sep 2011) | 30 lines
    
    Fix deadlock when using dummy channels.
    
    Dummy channels created by ast_dummy_channel_alloc() should be destoyed by
    ast_channel_unref().  Using ast_channel_release() needlessly grabs the
    channel container lock and can cause a deadlock as a result.
    
    * Analyzed use of ast_dummy_channel_alloc() and made use
    ast_channel_unref() when done with the dummy channel.  (Primary reason for
    the reported deadlock.)
    
    * Made app_dial.c:dial_exec_full() not call ast_call() holding any channel
    locks.  Chan_local could not perform deadlock avoidance correctly.
    (Potential deadlock exposed by this issue.  Secondary reason for the
    reported deadlock since the held lock was part of the deadlock chain.)
    
    * Fixed some uses of ast_dummy_channel_alloc() not checking the returned
    channel pointer for failure.
    
    * Fixed some potential chan=NULL pointer usage in func_odbc.c.  Protected
    by testing the bogus_chan value.
    
    * Fixed needlessly clearing a 1024 char auto array when setting the first
    char to zero is enough in manager.c:action_getvar().
    
    (closes issue ASTERISK-18613)
    Reported by: Thomas Arimont
    Patches:
          jira_asterisk_18613_v1.8.patch (license #5621) patch uploaded by rmudgett
    Tested by: Thomas Arimont
  ........
................


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@337975 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 21 insertions, 12 deletions

diff --git a/funcs/func_odbc.c b/funcs/func_odbc.c
index e940021a3..eeb7d3be1 100644
--- a/funcs/func_odbc.c
+++ b/funcs/func_odbc.c
@@ -267,7 +267,7 @@ static int acf_odbc_write(struct ast_channel *chan, const char *cmd, char *s, co
 			ast_autoservice_stop(chan);
 			pbx_builtin_setvar_helper(chan, "ODBCSTATUS", status);
 		} else {
-			ast_channel_release(chan);
+			ast_channel_unref(chan);
 		}
 		return -1;
 	}
@@ -292,7 +292,7 @@ static int acf_odbc_write(struct ast_channel *chan, const char *cmd, char *s, co
 	ast_str_substitute_variables(&insertbuf, 0, chan, query->sql_insert);
 
 	if (bogus_chan) {
-		chan = ast_channel_release(chan);
+		chan = ast_channel_unref(chan);
 	} else {
 		/* Restore prior values */
 		for (i = 0; i < args.argc; i++) {
@@ -474,7 +474,7 @@ static int acf_odbc_read(struct ast_channel *chan, const char *cmd, char *s, cha
 	ast_str_substitute_variables(&sql, 0, chan, query->sql_read);
 
 	if (bogus_chan) {
-		chan = ast_channel_release(chan);
+		chan = ast_channel_unref(chan);
 	} else {
 		/* Restore prior values */
 		for (x = 0; x < args.argc; x++) {
@@ -596,11 +596,9 @@ static int acf_odbc_read(struct ast_channel *chan, const char *cmd, char *s, cha
 				SQLFreeHandle(SQL_HANDLE_STMT, stmt);
 				ast_odbc_release_obj(obj);
 				obj = NULL;
-				pbx_builtin_setvar_helper(chan, "ODBCSTATUS", "MEMERROR");
-				if (chan)
+				if (!bogus_chan) {
+					pbx_builtin_setvar_helper(chan, "ODBCSTATUS", "MEMERROR");
 					ast_autoservice_stop(chan);
-				if (bogus_chan) {
-					ast_channel_release(chan);
 				}
 				return -1;
 			}
@@ -631,9 +629,11 @@ static int acf_odbc_read(struct ast_channel *chan, const char *cmd, char *s, cha
 						SQLFreeHandle(SQL_HANDLE_STMT, stmt);
 						ast_odbc_release_obj(obj);
 						obj = NULL;
-						pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
-						pbx_builtin_setvar_helper(chan, "ODBCSTATUS", "MEMERROR");
-						ast_autoservice_stop(chan);
+						if (!bogus_chan) {
+							pbx_builtin_setvar_helper(chan, "ODBCROWS", rowcount);
+							pbx_builtin_setvar_helper(chan, "ODBCSTATUS", "MEMERROR");
+							ast_autoservice_stop(chan);
+						}
 						return -1;
 					}
 					resultset = tmp;
@@ -1142,6 +1142,10 @@ static char *cli_odbc_read(struct ast_cli_entry *e, int cmd, struct ast_cli_args
 	char_args = ast_strdupa(a->argv[3]);
 
 	chan = ast_dummy_channel_alloc();
+	if (!chan) {
+		AST_RWLIST_UNLOCK(&queries);
+		return CLI_FAILURE;
+	}
 
 	AST_STANDARD_APP_ARGS(args, char_args);
 	for (i = 0; i < args.argc; i++) {
@@ -1150,7 +1154,7 @@ static char *cli_odbc_read(struct ast_cli_entry *e, int cmd, struct ast_cli_args
 	}
 
 	ast_str_substitute_variables(&sql, 0, chan, query->sql_read);
-	chan = ast_channel_release(chan);
+	chan = ast_channel_unref(chan);
 
 	if (a->argc == 5 && !strcmp(a->argv[4], "exec")) {
 		/* Execute the query */
@@ -1352,6 +1356,10 @@ static char *cli_odbc_write(struct ast_cli_entry *e, int cmd, struct ast_cli_arg
 	char_values = ast_strdupa(a->argv[4]);
 
 	chan = ast_dummy_channel_alloc();
+	if (!chan) {
+		AST_RWLIST_UNLOCK(&queries);
+		return CLI_FAILURE;
+	}
 
 	AST_STANDARD_APP_ARGS(args, char_args);
 	for (i = 0; i < args.argc; i++) {
@@ -1370,7 +1378,8 @@ static char *cli_odbc_write(struct ast_cli_entry *e, int cmd, struct ast_cli_arg
 	pbx_builtin_pushvar_helper(chan, "VALUE", S_OR(a->argv[4], ""));
 	ast_str_substitute_variables(&sql, 0, chan, query->sql_write);
 	ast_debug(1, "SQL is %s\n", ast_str_buffer(sql));
-	chan = ast_channel_release(chan);
+
+	chan = ast_channel_unref(chan);
 
 	if (a->argc == 6 && !strcmp(a->argv[5], "exec")) {
 		/* Execute the query */