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From:   Jann Horn <jannh@google.com>
To:     Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>
Cc:     Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        linux-crypto@vger.kernel.org,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>,
        linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] s390/crypto: fix scatterwalk_unmap() callers in AES-GCM
Date:   Tue, 17 May 2022 16:30:47 +0200
Message-Id: <20220517143047.3054498-1-jannh@google.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

The argument of scatterwalk_unmap() is supposed to be the void* that was
returned by the previous scatterwalk_map() call.
The s390 AES-GCM implementation was instead passing the pointer to the
struct scatter_walk.

This doesn't actually break anything because scatterwalk_unmap() only uses
its argument under CONFIG_HIGHMEM and ARCH_HAS_FLUSH_ON_KUNMAP.

Note that I have not tested this patch in any way, not even compile-tested
it.

Fixes: bf7fa038707c ("s390/crypto: add s390 platform specific aes gcm suppo=
rt.")
Signed-off-by: Jann Horn <jannh@google.com>
---
IDK which tree this has to go through - s390 or crypto?
maybe s390 is better, since they can actually test it?

 arch/s390/crypto/aes_s390.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index 54c7536f2482..1023e9d43d44 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -701,7 +701,7 @@ static inline void _gcm_sg_unmap_and_advance(struct gcm=
_sg_walk *gw,
 					     unsigned int nbytes)
 {
 	gw->walk_bytes_remain -=3D nbytes;
-	scatterwalk_unmap(&gw->walk);
+	scatterwalk_unmap(gw->walk_ptr);
 	scatterwalk_advance(&gw->walk, nbytes);
 	scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
 	gw->walk_ptr =3D NULL;
@@ -776,7 +776,7 @@ static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsi=
gned int minbytesneeded)
 		goto out;
 	}
=20
-	scatterwalk_unmap(&gw->walk);
+	scatterwalk_unmap(gw->walk_ptr);
 	gw->walk_ptr =3D NULL;
=20
 	gw->ptr =3D gw->buf;

base-commit: 42226c989789d8da4af1de0c31070c96726d990c
--=20
2.36.0.550.gb090851708-goog