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 "alg" is incompatible and not intended to be used with mcryptd. A flag CRYPTO_ALG_MCRYPT is being added to mcryptd compatible algorithms' cra_flags. The compatability is checked when mcryptd spawn off an algorithm. Link: http://marc.info/?l=linux-crypto-vger&m=148063683310477&w=2 Cc: stable@xxxxxxxxxxxxxxx Reported-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> Tested-by: Megha Dey <megha.dey@xxxxxxxxxxxxxxx> Signed-off-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> --- arch/x86/crypto/sha1-mb/sha1_mb.c | 3 ++- arch/x86/crypto/sha256-mb/sha256_mb.c | 3 ++- arch/x86/crypto/sha512-mb/sha512_mb.c | 3 ++- crypto/mcryptd.c | 6 ++++++ include/linux/crypto.h | 6 ++++++ 5 files changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/x86/crypto/sha1-mb/sha1_mb.c b/arch/x86/crypto/sha1-mb/sha1_mb.c index acf9fdf..475959db 100644 --- a/arch/x86/crypto/sha1-mb/sha1_mb.c +++ b/arch/x86/crypto/sha1-mb/sha1_mb.c @@ -770,7 +770,8 @@ static struct ahash_alg sha1_mb_areq_alg = { */ .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | - CRYPTO_ALG_INTERNAL, + CRYPTO_ALG_INTERNAL | + CRYPTO_ALG_MCRYPT, .cra_blocksize = SHA1_BLOCK_SIZE, .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT diff --git a/arch/x86/crypto/sha256-mb/sha256_mb.c b/arch/x86/crypto/sha256-mb/sha256_mb.c index 7926a22..f33b592 100644 --- a/arch/x86/crypto/sha256-mb/sha256_mb.c +++ b/arch/x86/crypto/sha256-mb/sha256_mb.c @@ -768,7 +768,8 @@ static struct ahash_alg sha256_mb_areq_alg = { */ .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | - CRYPTO_ALG_INTERNAL, + CRYPTO_ALG_INTERNAL | + CRYPTO_ALG_MCRYPT, .cra_blocksize = SHA256_BLOCK_SIZE, .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT diff --git a/arch/x86/crypto/sha512-mb/sha512_mb.c b/arch/x86/crypto/sha512-mb/sha512_mb.c index 9c1bb6d..13aa2e6 100644 --- a/arch/x86/crypto/sha512-mb/sha512_mb.c +++ b/arch/x86/crypto/sha512-mb/sha512_mb.c @@ -783,7 +783,8 @@ static struct ahash_alg sha512_mb_areq_alg = { */ .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | - CRYPTO_ALG_INTERNAL, + CRYPTO_ALG_INTERNAL | + CRYPTO_ALG_MCRYPT, .cra_blocksize = SHA512_BLOCK_SIZE, .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT diff --git a/crypto/mcryptd.c b/crypto/mcryptd.c index 94ee44a..5c40e13 100644 --- a/crypto/mcryptd.c +++ b/crypto/mcryptd.c @@ -500,6 +500,12 @@ static int mcryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb, alg = &halg->base; pr_debug("crypto: mcryptd hash alg: %s\n", alg->cra_name); + + if (!(alg->cra_flags & CRYPTO_ALG_MCRYPT)) { + err = -EINVAL; + goto out_put_alg; + } + inst = mcryptd_alloc_instance(alg, ahash_instance_headroom(), sizeof(*ctx)); err = PTR_ERR(inst); diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 167aea2..e47d5a8 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -106,6 +106,12 @@ #define CRYPTO_ALG_INTERNAL 0x00002000 /* + * Mark cipher as compatible with mcryptd + * for multi-buffer processing + */ +#define CRYPTO_ALG_MCRYPT 0x00004000 + +/* * Transform masks and values (for crt_flags). */ #define CRYPTO_TFM_REQ_MASK 0x000fff00 -- 2.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
