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[1/4] crypto: vmac - require a block cipher with 128-bit block size

Message ID 20180618172240.46651-2-ebiggers3@gmail.com (mailing list archive)
State Accepted
Delegated to: Herbert Xu
Headers show

Commit Message

Eric Biggers June 18, 2018, 5:22 p.m. UTC 
From: Eric Biggers <ebiggers@google.com>

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>
---
 crypto/vmac.c | 4 ++++
 1 file changed, 4 insertions(+)
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Patch

diff --git a/crypto/vmac.c b/crypto/vmac.c
index df76a816cfb2..3034454a3713 100644
--- a/crypto/vmac.c
+++ b/crypto/vmac.c
@@ -655,6 +655,10 @@  static int vmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 	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))