dns_core: Protect against array index violation.

Add a check to allocate_dns_record to prevent calling a pointer
retrieved from beyond dns_alloc_table.

ASTERISK-27495 #close

Change-Id: Ie2f6e4991cea46baa12e837bd64cc22b44d322bb

diff --git a/main/dns_core.c b/main/dns_core.c
index a243b4bdd3fbd328c00d9641c6dc4e3d956b8566..3e270aff7eea89bfa810ede62e7775748ca7ad15 100644 (file)
--- a/main/dns_core.c
+++ b/main/dns_core.c
@@ -447,9 +447,13 @@ static dns_alloc_fn dns_alloc_table [] = {
        [T_SRV] = dns_srv_alloc,
 };
 
-static struct ast_dns_record *allocate_dns_record(int rr_type, struct ast_dns_query *query, const char *data, const size_t size)
+static struct ast_dns_record *allocate_dns_record(unsigned int rr_type, struct ast_dns_query *query, const char *data, const size_t size)
 {
-       dns_alloc_fn allocator = dns_alloc_table[rr_type] ?: generic_record_alloc;
+       dns_alloc_fn allocator = generic_record_alloc;
+
+       if (rr_type < ARRAY_LEN(dns_alloc_table) && dns_alloc_table[rr_type]) {
+               allocator = dns_alloc_table[rr_type];
+       }
 
        return allocator(query, data, size);
 }