Fix NULL pointer dereference in `asn1_ex_i2c()`, crypto/asn1/tasn_enc.c

Adds handling of V_ASN1_UNDEF to avoid NULL dereference
in case ASN1 structure contains an element of type ASN1_TYPE
without initializing its value (i.e. default constructed)

CLA: trivial

Signed-off-by: Andrey Tsygunka <aitsygunka@yandex.ru>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/27100)

diff --git a/crypto/asn1/tasn_enc.c b/crypto/asn1/tasn_enc.c
index dab5f9f278f3a4f0b0cc23938b42f1861596c3e0..e0ee7604345ef7af4dfc2e2a285dcf1873e5f49e 100644 (file)
--- a/crypto/asn1/tasn_enc.c
+++ b/crypto/asn1/tasn_enc.c
@@ -565,6 +565,9 @@ static int asn1_ex_i2c(const ASN1_VALUE **pval, unsigned char *cout, int *putype
             return -1;
         break;
 
+    case V_ASN1_UNDEF:
+        return -2;
+
     case V_ASN1_NULL:
         cont = NULL;
         len = 0;