1 files changed, 8 insertions, 3 deletions

diff --git a/src/lib/libcrypto/asn1/tasn_enc.c b/src/lib/libcrypto/asn1/tasn_enc.c
index 55e65895f8..1b9cfa1a0e 100644
--- a/src/lib/libcrypto/asn1/tasn_enc.c
+++ b/src/lib/libcrypto/asn1/tasn_enc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tasn_enc.c,v 1.27 2022/11/26 16:08:50 tb Exp $ */
+/* $OpenBSD: tasn_enc.c,v 1.28 2023/03/06 08:08:31 tb Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2000.
  */
@@ -108,7 +108,7 @@ asn1_item_flags_i2d(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it,
 {
         if (out && !*out) {
                 unsigned char *p, *buf;
-                int len;
+                int len, len2;
                 len = ASN1_item_ex_i2d(&val, NULL, it, -1, flags);
                 if (len <= 0)
                         return len;
@@ -116,7 +116,12 @@ asn1_item_flags_i2d(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it,
                 if (!buf)
                         return -1;
                 p = buf;
-                ASN1_item_ex_i2d(&val, &p, it, -1, flags);
+                len2 = ASN1_item_ex_i2d(&val, &p, it, -1, flags);
+                if (len2 != len) {
+                        freezero(buf, len);
+                        ASN1error(ASN1_R_LENGTH_ERROR);
+                        return -1;
+                }
                 *out = buf;
                 return len;
         }