Fix stack-use-after-scope in dns_message_checksig test

Previously stack with buffer for test dns message went out of scope
before the message was processed. For fuzz testing its better to avoid
allocation, so let's avoid allocations completely and use simplest
possible static buffer.

Fixes: #3565
(cherry picked from commit 16377100ae145f2994e6e18f4dfc586403f31ec8)

diff --git a/fuzz/dns_message_checksig.c b/fuzz/dns_message_checksig.c
index 70da0f9d5a37684fc033d41267ba0143f75d1228..af01b9ad57734046146b9fb459607b01b720e9ef 100644 (file)
--- a/fuzz/dns_message_checksig.c
+++ b/fuzz/dns_message_checksig.c
@@ -213,7 +213,7 @@ create_message(dns_message_t **messagep, const uint8_t *data, size_t size,
        isc_result_t result;
        dns_message_t *message = NULL;
        isc_buffer_t b;
-       unsigned char buf[65535];
+       static unsigned char buf[65535];
 
        isc_buffer_init(&b, buf, sizeof(buf));