Avoid NULL pointer dereference. Fixes #9043.

Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9059)

(cherry picked from commit 9fd6f7d1cd2a3c8e2bc69dcb8bde8406eb6c2623)

apps/req.c

@@ -881,9 +881,19 @@ int req_main(int argc, char **argv)
 
     if (text) {
         if (x509)
-            X509_print_ex(out, x509ss, get_nameopt(), reqflag);
+            ret = X509_print_ex(out, x509ss, get_nameopt(), reqflag);
         else
-            X509_REQ_print_ex(out, req, get_nameopt(), reqflag);
+            ret = X509_REQ_print_ex(out, req, get_nameopt(), reqflag);
+
+        if (ret == 0) {
+            if (x509)
+              BIO_printf(bio_err, "Error printing certificate\n");
+            else
+              BIO_printf(bio_err, "Error printing certificate request\n");
+
+            ERR_print_errors(bio_err);
+            goto end;
+        }
     }
 
     if (subject) {

crypto/err/openssl.txt

@@ -3011,6 +3011,7 @@ X509_R_CERT_ALREADY_IN_HASH_TABLE:101:cert already in hash table
 X509_R_CRL_ALREADY_DELTA:127:crl already delta
 X509_R_CRL_VERIFY_FAILURE:131:crl verify failure
 X509_R_IDP_MISMATCH:128:idp mismatch
+X509_R_INVALID_ATTRIBUTES:138:invalid attributes
 X509_R_INVALID_DIRECTORY:113:invalid directory
 X509_R_INVALID_FIELD_NAME:119:invalid field name
 X509_R_INVALID_TRUST:123:invalid trust

crypto/x509/t_req.c

@@ -127,6 +127,10 @@ int X509_REQ_print_ex(BIO *bp, X509_REQ *x, unsigned long nmflags,
                 if ((j = i2a_ASN1_OBJECT(bp, aobj)) > 0) {
                     ii = 0;
                     count = X509_ATTRIBUTE_count(a);
+                    if (count == 0) {
+                      X509err(X509_F_X509_REQ_PRINT_EX, X509_R_INVALID_ATTRIBUTES);
+                      return 0;
+                    }
  get_next:
                     at = X509_ATTRIBUTE_get0_type(a, ii);
                     type = at->type;

crypto/x509/x509_err.c

@@ -123,6 +123,8 @@ static const ERR_STRING_DATA X509_str_reasons[] = {
     {ERR_PACK(ERR_LIB_X509, 0, X509_R_CRL_VERIFY_FAILURE),
     "crl verify failure"},
     {ERR_PACK(ERR_LIB_X509, 0, X509_R_IDP_MISMATCH), "idp mismatch"},
+    {ERR_PACK(ERR_LIB_X509, 0, X509_R_INVALID_ATTRIBUTES),
+    "invalid attributes"},
     {ERR_PACK(ERR_LIB_X509, 0, X509_R_INVALID_DIRECTORY), "invalid directory"},
     {ERR_PACK(ERR_LIB_X509, 0, X509_R_INVALID_FIELD_NAME),
     "invalid field name"},

include/openssl/x509err.h

@@ -97,6 +97,7 @@ int ERR_load_X509_strings(void);
 # define X509_R_CRL_ALREADY_DELTA                         127
 # define X509_R_CRL_VERIFY_FAILURE                        131
 # define X509_R_IDP_MISMATCH                              128
+# define X509_R_INVALID_ATTRIBUTES                        138
 # define X509_R_INVALID_DIRECTORY                         113
 # define X509_R_INVALID_FIELD_NAME                        119
 # define X509_R_INVALID_TRUST                             123