From:   Daniel Axtens <dja@axtens.net>
To:     omosnacek@gmail.com, linux-crypto@vger.kernel.org,
        Herbert Xu <herbert@gondor.apana.org.au>
Cc:     marcelo.cerri@canonical.com, Stephan Mueller <smueller@chronox.de>,
        leo.barbosa@canonical.com, linuxppc-dev@lists.ozlabs.org,
        nayna@linux.ibm.com, pfsmorigo@gmail.com, leitao@debian.org
Subject: [PATCH] crypto: vmx - fix copy-paste error in CTR mode
Date:   Fri, 15 Mar 2019 13:09:01 +1100
Message-Id: <20190315020901.16509-1-dja@axtens.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-crypto-owner@vger.kernel.org
Precedence: bulk

The original assembly imported from OpenSSL has two copy-paste
errors in handling CTR mode. When dealing with a 2 or 3 block tail,
the code branches to the CBC decryption exit path, rather than to
the CTR exit path.

This leads to corruption of the IV, which leads to subsequent blocks
being corrupted.

This can be detected with libkcapi test suite, which is available at
https://github.com/smuellerDD/libkcapi

Reported-by: Ondrej Mosnáček <omosnacek@gmail.com>
Fixes: 5c380d623ed3 ("crypto: vmx - Add support for VMS instructions by ASM")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 drivers/crypto/vmx/aesp8-ppc.pl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/vmx/aesp8-ppc.pl b/drivers/crypto/vmx/aesp8-ppc.pl
index d6a9f63d65ba..de78282b8f44 100644
--- a/drivers/crypto/vmx/aesp8-ppc.pl
+++ b/drivers/crypto/vmx/aesp8-ppc.pl
@@ -1854,7 +1854,7 @@ Lctr32_enc8x_three:
 	stvx_u		$out1,$x10,$out
 	stvx_u		$out2,$x20,$out
 	addi		$out,$out,0x30
-	b		Lcbc_dec8x_done
+	b		Lctr32_enc8x_done
 
 .align	5
 Lctr32_enc8x_two:
@@ -1866,7 +1866,7 @@ Lctr32_enc8x_two:
 	stvx_u		$out0,$x00,$out
 	stvx_u		$out1,$x10,$out
 	addi		$out,$out,0x20
-	b		Lcbc_dec8x_done
+	b		Lctr32_enc8x_done
 
 .align	5
 Lctr32_enc8x_one:
-- 
2.19.1