1 files changed, 11 insertions, 6 deletions

diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index 486aa93646f7..1b3b1da1fd35 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -223,9 +223,10 @@ remainder:
         }
 
         /*
-         * Copy up to the next whole block size
+         * Copy any data less than an entire block
          */
         if (byte_count < DEFAULT_BLK_SZ) {
+empty_rbuf:
                 for (; ctx->rand_data_valid < DEFAULT_BLK_SZ;
                         ctx->rand_data_valid++) {
                         *ptr = ctx->rand_data[ctx->rand_data_valid];
@@ -240,18 +241,22 @@ remainder:
          * Now copy whole blocks
          */
         for (; byte_count >= DEFAULT_BLK_SZ; byte_count -= DEFAULT_BLK_SZ) {
-                if (_get_more_prng_bytes(ctx) < 0) {
-                        memset(buf, 0, nbytes);
-                        err = -EINVAL;
-                        goto done;
+                if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
+                        if (_get_more_prng_bytes(ctx) < 0) {
+                                memset(buf, 0, nbytes);
+                                err = -EINVAL;
+                                goto done;
+                        }
                 }
+                if (ctx->rand_data_valid > 0)
+                        goto empty_rbuf;
                 memcpy(ptr, ctx->rand_data, DEFAULT_BLK_SZ);
                 ctx->rand_data_valid += DEFAULT_BLK_SZ;
                 ptr += DEFAULT_BLK_SZ;
         }
 
         /*
-         * Now copy any extra partial data
+         * Now go back and get any remaining partial block
          */
         if (byte_count)
                 goto remainder;