diff options
| author | tim <tim.c.chen@linux.intel.com> | 2016-12-05 11:46:31 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-12-15 08:49:22 -0800 |
| commit | 9a3baed9103bc413a5e98e13e31cd8ae7c0b5563 (patch) | |
| tree | 0d1384756b6d81a69014758c0e2a5e18effad9e1 /crypto | |
| parent | c4db8a7d1e0c16287642414fe16d85d1eaeb8923 (diff) | |
crypto: mcryptd - Check mcryptd algorithm compatibility
commit 48a992727d82cb7db076fa15d372178743b1f4cd upstream.
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
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/mcryptd.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/crypto/mcryptd.c b/crypto/mcryptd.c index fe5b495a434d..a0ceb41d5ccc 100644 --- a/crypto/mcryptd.c +++ b/crypto/mcryptd.c @@ -258,18 +258,22 @@ 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)) - *type |= CRYPTO_ALG_INTERNAL; - if ((algt->mask & CRYPTO_ALG_INTERNAL)) - *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) @@ -498,7 +502,8 @@ 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; salg = shash_attr_alg(tb[1], type, mask); if (IS_ERR(salg)) |