From: Torsten Duwe <[email protected]>
At function exit, do not leave the expanded key in the rk struct
which got allocated on the stack.
Signed-off-by: Torsten Duwe <[email protected]>
---
Another small fix from our FIPS evaluation. I hope you don't mind I merged
arm32 and arm64 into one patch -- this is really simple.
--- a/arch/arm/crypto/aes-neonbs-glue.c
+++ b/arch/arm/crypto/aes-neonbs-glue.c
@@ -138,6 +138,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
kernel_neon_begin();
aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
kernel_neon_end();
+ memzero_explicit(&rk, sizeof(rk));
return crypto_cipher_setkey(ctx->enc_tfm, in_key, key_len);
}
diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
index e3e27349a9fe..c0b980503643 100644
--- a/arch/arm64/crypto/aes-neonbs-glue.c
+++ b/arch/arm64/crypto/aes-neonbs-glue.c
@@ -151,6 +151,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
kernel_neon_begin();
aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
kernel_neon_end();
+ memzero_explicit(&rk, sizeof(rk));
return 0;
}
[+Ard]
On Fri, Mar 13, 2020 at 12:02:58PM +0100, Torsten Duwe wrote:
> From: Torsten Duwe <[email protected]>
>
> At function exit, do not leave the expanded key in the rk struct
> which got allocated on the stack.
>
> Signed-off-by: Torsten Duwe <[email protected]>
> ---
> Another small fix from our FIPS evaluation. I hope you don't mind I merged
> arm32 and arm64 into one patch -- this is really simple.
> --- a/arch/arm/crypto/aes-neonbs-glue.c
> +++ b/arch/arm/crypto/aes-neonbs-glue.c
> @@ -138,6 +138,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
> kernel_neon_begin();
> aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
> kernel_neon_end();
> + memzero_explicit(&rk, sizeof(rk));
>
> return crypto_cipher_setkey(ctx->enc_tfm, in_key, key_len);
> }
> diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
> index e3e27349a9fe..c0b980503643 100644
> --- a/arch/arm64/crypto/aes-neonbs-glue.c
> +++ b/arch/arm64/crypto/aes-neonbs-glue.c
> @@ -151,6 +151,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
> kernel_neon_begin();
> aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
> kernel_neon_end();
> + memzero_explicit(&rk, sizeof(rk));
>
> return 0;
> }
I'm certainly not a crypto person, but this looks sensible to me and I
couldn't find any other similar stack variable usage under
arch/arm64/crypto/ at a quick glance.
Acked-by: Will Deacon <[email protected]>
Will
On Tue, 17 Mar 2020 at 18:17, Will Deacon <[email protected]> wrote:
>
> [+Ard]
>
> On Fri, Mar 13, 2020 at 12:02:58PM +0100, Torsten Duwe wrote:
> > From: Torsten Duwe <[email protected]>
> >
> > At function exit, do not leave the expanded key in the rk struct
> > which got allocated on the stack.
> >
> > Signed-off-by: Torsten Duwe <[email protected]>
> > ---
> > Another small fix from our FIPS evaluation. I hope you don't mind I merged
> > arm32 and arm64 into one patch -- this is really simple.
> > --- a/arch/arm/crypto/aes-neonbs-glue.c
> > +++ b/arch/arm/crypto/aes-neonbs-glue.c
> > @@ -138,6 +138,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
> > kernel_neon_begin();
> > aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
> > kernel_neon_end();
> > + memzero_explicit(&rk, sizeof(rk));
> >
> > return crypto_cipher_setkey(ctx->enc_tfm, in_key, key_len);
> > }
> > diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
> > index e3e27349a9fe..c0b980503643 100644
> > --- a/arch/arm64/crypto/aes-neonbs-glue.c
> > +++ b/arch/arm64/crypto/aes-neonbs-glue.c
> > @@ -151,6 +151,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
> > kernel_neon_begin();
> > aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
> > kernel_neon_end();
> > + memzero_explicit(&rk, sizeof(rk));
> >
> > return 0;
> > }
>
> I'm certainly not a crypto person, but this looks sensible to me and I
> couldn't find any other similar stack variable usage under
> arch/arm64/crypto/ at a quick glance.
>
> Acked-by: Will Deacon <[email protected]>
>
Acked-by: Ard Biesheuvel <[email protected]>
On Fri, Mar 13, 2020 at 12:02:58PM +0100, Torsten Duwe wrote:
> From: Torsten Duwe <[email protected]>
>
> At function exit, do not leave the expanded key in the rk struct
> which got allocated on the stack.
>
> Signed-off-by: Torsten Duwe <[email protected]>
Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt