acl.c: Coerce a NULL pointer into the empty string

If an ACL is misconfigured in the realtime database (for instance, the
"rule" is blank) and Asterisk attempts to read the ACL, Asterisk will
crash.

ASTERISK-28978 #close

Change-Id: Ic1536c4df856231bfd2da00128f7822224d77610

diff --git a/main/acl.c b/main/acl.c
index 3d329768573d7c18e3dfcdd08c8d5ac43456d786..b1b838fd224f0add56afd8bb9ba7e3275feb093c 100644 (file)
--- a/main/acl.c
+++ b/main/acl.c
@@ -580,7 +580,7 @@ static struct ast_ha *append_ha_core(const char *sense, const char *stuff, struc
        struct ast_ha *ha;
        struct ast_ha *prev = NULL;
        struct ast_ha *ret;
-       char *tmp, *list = ast_strdupa(stuff);
+       char *tmp, *list = ast_strdupa(stuff ?: "");
        char *address = NULL, *mask = NULL;
        int addr_is_v4;
        int allowing = strncasecmp(sense, "p", 1) ? AST_SENSE_DENY : AST_SENSE_ALLOW;