crypto: mcryptd - Check mcryptd algorithm compatibility (48a99272) · Commits · 戴 / test

Algorithms not compatible with mcryptd could be spawned by mcryptd with a direct crypto_alloc_tfm invocation using a "mcryptd(alg)" name construct. This causes mcryptd to crash the kernel if an arbitrary "alg" is incompatible and not intended to be used with mcryptd. It is an issue if AF_ALG tries to spawn mcryptd(alg) to expose it externally. But such algorithms must be used internally and not be exposed. We added a check to enforce that only internal algorithms are allowed with mcryptd at the time mcryptd is spawning an algorithm. Link: http://marc.info/?l=linux-crypto-vger&m=148063683310477&w=2 Cc: stable@vger.kernel.org Reported-by:

Mikulas Patocka <mpatocka@redhat.com> Signed-off-by:

Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au>

crypto/mcryptd.c

+12 −7

Original line number	Original line	Diff line number	Diff line
	@@ -254,18 +254,22 @@ out_free_inst:
	goto out;		goto out;
	}		}

	static inline void mcryptd_check_internal(struct rtattr *tb, u32 type,		static inline bool mcryptd_check_internal(struct rtattr *tb, u32 type,
	u32 *mask)		u32 *mask)
	{		{
	struct crypto_attr_type *algt;		struct crypto_attr_type *algt;

	algt = crypto_get_attr_type(tb);		algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))		if (IS_ERR(algt))
	return;		return false;
	if ((algt->type & CRYPTO_ALG_INTERNAL))
	*type \|= CRYPTO_ALG_INTERNAL;		*type \|= algt->type & CRYPTO_ALG_INTERNAL;
	if ((algt->mask & CRYPTO_ALG_INTERNAL))		*mask \|= algt->mask & CRYPTO_ALG_INTERNAL;
	*mask \|= CRYPTO_ALG_INTERNAL;
			if (type & mask & CRYPTO_ALG_INTERNAL)
			return true;
			else
			return false;
	}		}

	static int mcryptd_hash_init_tfm(struct crypto_tfm *tfm)		static int mcryptd_hash_init_tfm(struct crypto_tfm *tfm)
	@@ -492,7 +496,8 @@ static int mcryptd_create_hash(struct crypto_template tmpl, struct rtattr *tb,
	u32 mask = 0;		u32 mask = 0;
	int err;		int err;

	mcryptd_check_internal(tb, &type, &mask);		if (!mcryptd_check_internal(tb, &type, &mask))
			return -EINVAL;

	halg = ahash_attr_alg(tb[1], type, mask);		halg = ahash_attr_alg(tb[1], type, mask);
	if (IS_ERR(halg))		if (IS_ERR(halg))

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