crypto: s390/aes - Fix buffer overread in CTR mode

commit d07f951903fa9922c375b8ab1ce81b18a0034e3b upstream.

When processing the last block, the s390 ctr code will always read
a whole block, even if there isn't a whole block of data left.  Fix
this by using the actual length left and copy it into a buffer first
for processing.

Fixes: 0200f3ecc196 ("crypto: s390 - add System z hardware support for CTR mode")
Cc: <stable@vger.kernel.org>
Reported-by: Guangwu Zhang <guazhang@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewd-by: Harald Freudenberger <freude@de.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index c773820..c6fe540 100644 (file)
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -597,7 +597,9 @@ static int ctr_aes_crypt(struct skcipher_request *req)
         * final block may be < AES_BLOCK_SIZE, copy only nbytes
         */
        if (nbytes) {
-               cpacf_kmctr(sctx->fc, sctx->key, buf, walk.src.virt.addr,
+               memset(buf, 0, AES_BLOCK_SIZE);
+               memcpy(buf, walk.src.virt.addr, nbytes);
+               cpacf_kmctr(sctx->fc, sctx->key, buf, buf,
                            AES_BLOCK_SIZE, walk.iv);
                memcpy(walk.dst.virt.addr, buf, nbytes);
                crypto_inc(walk.iv, AES_BLOCK_SIZE);

diff --git a/arch/s390/crypto/paes_s390.c b/arch/s390/crypto/paes_s390.c
index 8b541e4..55ee556 100644 (file)
--- a/arch/s390/crypto/paes_s390.c
+++ b/arch/s390/crypto/paes_s390.c
@@ -693,9 +693,11 @@ static int ctr_paes_crypt(struct skcipher_request *req)
         * final block may be < AES_BLOCK_SIZE, copy only nbytes
         */
        if (nbytes) {
+               memset(buf, 0, AES_BLOCK_SIZE);
+               memcpy(buf, walk.src.virt.addr, nbytes);
                while (1) {
                        if (cpacf_kmctr(ctx->fc, &param, buf,
-                                       walk.src.virt.addr, AES_BLOCK_SIZE,
+                                       buf, AES_BLOCK_SIZE,
                                        walk.iv) == AES_BLOCK_SIZE)
                                break;
                        if (__paes_convert_key(ctx))