path: root/crypto
diff options
authortim <tim.c.chen@linux.intel.com>2016-12-05 11:46:31 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2016-12-07 19:55:37 +0800
commit48a992727d82cb7db076fa15d372178743b1f4cd (patch)
tree2cc24a02c43a2d4d6382916f4614b118b82d27b4 /crypto
parentcrypto: algif_aead - fix AEAD tag memory handling (diff)
crypto: mcryptd - Check mcryptd algorithm compatibility
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>
Diffstat (limited to 'crypto')
1 files changed, 12 insertions, 7 deletions
diff --git a/crypto/mcryptd.c b/crypto/mcryptd.c
index 94ee44acd465..c207458d6299 100644
--- a/crypto/mcryptd.c
+++ b/crypto/mcryptd.c
@@ -254,18 +254,22 @@ out_free_inst:
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)
struct crypto_attr_type *algt;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
- return;
- if ((algt->type & CRYPTO_ALG_INTERNAL))
- if ((algt->mask & CRYPTO_ALG_INTERNAL))
+ return false;
+ *type |= algt->type & CRYPTO_ALG_INTERNAL;
+ *mask |= algt->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)
@@ -492,7 +496,8 @@ static int mcryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
u32 mask = 0;
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);
if (IS_ERR(halg))