crypto: vmac - require a block cipher with 128-bit block size
commit 73bf20ef3df262026c3470241ae4ac8196943ffa upstream.
The VMAC template assumes the block cipher has a 128-bit block size, but
it failed to check for that. Thus it was possible to instantiate it
using a 64-bit block size cipher, e.g. "vmac(cast5)", causing
uninitialized memory to be used.
Add the needed check when instantiating the template.
Fixes: f1939f7c5645 ("crypto: vmac - New hash algorithm for intel_txt support")
Cc: <stable@vger.kernel.org> # v2.6.32+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/crypto/vmac.c b/crypto/vmac.c
index df76a81..3034454 100644
--- a/crypto/vmac.c
+++ b/crypto/vmac.c
@@ -655,6 +655,10 @@
if (IS_ERR(alg))
return PTR_ERR(alg);
+ err = -EINVAL;
+ if (alg->cra_blocksize != 16)
+ goto out_put_alg;
+
inst = shash_alloc_instance("vmac", alg);
err = PTR_ERR(inst);
if (IS_ERR(inst))