2021-03-01 10:33:36

by Yang Li

Subject: [PATCH] crypto: sun8i-ce: rename kfree() to kfree_sensitive()

Rename kfree() to kfree_sensitive() to make the intention of the API
more explicit.

fixed the following coccicheck:
./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:30:16-17: WARNING
opportunity for kfree_sensitive/kvfree_sensitive (memset at line 29)
./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:42:16-17: WARNING
opportunity for kfree_sensitive/kvfree_sensitive (memset at line 41)
./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:161:8-9: WARNING
opportunity for kfree_sensitive/kvfree_sensitive (memset at line 109)

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
---
drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
index cfde9ee..8259d52 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
@@ -27,7 +27,7 @@ void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);

memzero_explicit(ctx->seed, ctx->slen);
- kfree(ctx->seed);
+ kfree_sensitive(ctx->seed);
ctx->seed = NULL;
ctx->slen = 0;
}
@@ -39,7 +39,7 @@ int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,

if (ctx->seed && ctx->slen != slen) {
memzero_explicit(ctx->seed, ctx->slen);
- kfree(ctx->seed);
+ kfree_sensitive(ctx->seed);
ctx->slen = 0;
ctx->seed = NULL;
}
@@ -158,7 +158,7 @@ int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
}
memzero_explicit(d, todo);
err_iv:
- kfree(d);
+ kfree_sensitive(d);
err_mem:
return err;
}
--
1.8.3.1

2021-03-01 10:35:46

by Herbert Xu

Subject: Re: [PATCH] crypto: sun8i-ce: rename kfree() to kfree_sensitive()

On Mon, Mar 01, 2021 at 06:30:41PM +0800, Yang Li wrote:
> Rename kfree() to kfree_sensitive() to make the intention of the API
> more explicit.
>
> fixed the following coccicheck:
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:30:16-17: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 29)
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:42:16-17: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 41)
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:161:8-9: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 109)
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Yang Li <[email protected]>
> ---
> drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> index cfde9ee..8259d52 100644
> --- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> +++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> @@ -27,7 +27,7 @@ void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
> struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
>
> memzero_explicit(ctx->seed, ctx->slen);
> - kfree(ctx->seed);
> + kfree_sensitive(ctx->seed);

Any reason why you're keeping the memzero?

Thanks,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

2021-03-01 10:40:00

by Christophe Leroy

Subject: Re: [PATCH] crypto: sun8i-ce: rename kfree() to kfree_sensitive()

Le 01/03/2021 à 11:30, Yang Li a écrit :
> Rename kfree() to kfree_sensitive() to make the intention of the API
> more explicit.

As far as I understand, you are not renaming kfree() to kfree_sensitive().

You are making a change to use kfree_sensitive() instead of using kfree().

Christophe

>
> fixed the following coccicheck:
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:30:16-17: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 29)
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:42:16-17: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 41)
> ./drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c:161:8-9: WARNING
> opportunity for kfree_sensitive/kvfree_sensitive (memset at line 109)
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Yang Li <[email protected]>
> ---
> drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> index cfde9ee..8259d52 100644
> --- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> +++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c
> @@ -27,7 +27,7 @@ void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
> struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
>
> memzero_explicit(ctx->seed, ctx->slen);
> - kfree(ctx->seed);
> + kfree_sensitive(ctx->seed);
> ctx->seed = NULL;
> ctx->slen = 0;
> }
> @@ -39,7 +39,7 @@ int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,
>
> if (ctx->seed && ctx->slen != slen) {
> memzero_explicit(ctx->seed, ctx->slen);
> - kfree(ctx->seed);
> + kfree_sensitive(ctx->seed);
> ctx->slen = 0;
> ctx->seed = NULL;
> }
> @@ -158,7 +158,7 @@ int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
> }
> memzero_explicit(d, todo);
> err_iv:
> - kfree(d);
> + kfree_sensitive(d);
> err_mem:
> return err;
> }
>