crypto: sha512 - Fix byte counter overflow in SHA-512

commit 25c3d30c918207556ae1d6e663150ebdf902186b upstream.

The current code only increments the upper 64 bits of the SHA-512 byte
counter when the number of bytes hashed happens to hit 2^64 exactly.

This patch increments the upper 64 bits whenever the lower 64 bits
overflows.

Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/crypto/sha512_generic.c b/crypto/sha512_generic.c
index 107f6f7..dd30f40 100644 (file)
--- a/crypto/sha512_generic.c
+++ b/crypto/sha512_generic.c
@@ -174,7 +174,7 @@ sha512_update(struct shash_desc *desc, const u8 *data, unsigned int len)
        index = sctx->count[0] & 0x7f;
 
        /* Update number of bytes */
-       if (!(sctx->count[0] += len))
+       if ((sctx->count[0] += len) < len)
                sctx->count[1]++;
 
         part_len = 128 - index;