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Commit 7b2cd92a authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: api - Fix zeroing on free 



Geert Uytterhoeven pointed out that we're not zeroing all the
memory when freeing a transform.  This patch fixes it by calling
ksize to ensure that we zero everything in sight.

Reported-by: default avatarGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 4abfd73e

crypto/api.c

+10 −10
Original line number Diff line number Diff line
@@ -559,32 +559,32 @@ struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, 
EXPORT_SYMBOL_GPL(crypto_alloc_tfm);



/*

 *	crypto_free_tfm - Free crypto transform

 *	crypto_destroy_tfm - Free crypto transform

 *	@mem: Start of tfm slab

 *	@tfm: Transform to free

 *

 *	crypto_free_tfm() frees up the transform and any associated resources,

 *	This function frees up the transform and any associated resources,

 *	then drops the refcount on the associated algorithm.

 */

void crypto_free_tfm(struct crypto_tfm *tfm)

void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)

{

	struct crypto_alg *alg;

	int size;



	if (unlikely(!tfm))

	if (unlikely(!mem))

		return;



	alg = tfm->__crt_alg;

	size = sizeof(*tfm) + alg->cra_ctxsize;

	size = ksize(mem);



	if (!tfm->exit && alg->cra_exit)

		alg->cra_exit(tfm);

	crypto_exit_ops(tfm);

	crypto_mod_put(alg);

	memset(tfm, 0, size);

	kfree(tfm);

	memset(mem, 0, size);

	kfree(mem);

}



EXPORT_SYMBOL_GPL(crypto_free_tfm);

EXPORT_SYMBOL_GPL(crypto_destroy_tfm);



int crypto_has_alg(const char *name, u32 type, u32 mask)

{

include/linux/crypto.h

+6 −1
Original line number Diff line number Diff line
@@ -552,7 +552,12 @@ struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, 
				    const struct crypto_type *frontend,

				    u32 type, u32 mask);

struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask);

void crypto_free_tfm(struct crypto_tfm *tfm);

void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm);



static inline void crypto_free_tfm(struct crypto_tfm *tfm)

{

	return crypto_destroy_tfm(tfm, tfm);

}



int alg_test(const char *driver, const char *alg, u32 type, u32 mask);