diff mbox series

[1/3] crypto: pass the flag CRYPTO_ALG_ALLOCATES_MEMORY

Message ID alpine.LRH.2.02.2006171108440.18714@file01.intranet.prod.int.rdu2.redhat.com (mailing list archive)
State Changes Requested
Delegated to: Herbert Xu
Headers show
Series [1/3] crypto: pass the flag CRYPTO_ALG_ALLOCATES_MEMORY | expand

Commit Message

Mikulas Patocka June 17, 2020, 3:09 p.m. UTC 
Introduce a new flag CRYPTO_ALG_ALLOCATES_MEMORY and pass it down the
crypto stack.

If the flag is set, then the crypto driver allocates memory in its request
routine. Such drivers are not suitable for disk encryption because
GFP_ATOMIC allocation can fail anytime (causing random I/O errors) and
GFP_KERNEL allocation can recurse into the block layer, causing a
deadlock.

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

---
 crypto/adiantum.c         |    3 ++-
 crypto/authenc.c          |    5 +++--
 crypto/authencesn.c       |    5 +++--
 crypto/ccm.c              |    7 ++++---
 crypto/chacha20poly1305.c |    5 +++--
 crypto/cryptd.c           |    9 ++++++---
 crypto/ctr.c              |    3 ++-
 crypto/cts.c              |    5 +++--
 crypto/essiv.c            |    5 +++--
 crypto/gcm.c              |   15 +++++++++------
 crypto/geniv.c            |    3 ++-
 crypto/lrw.c              |    5 +++--
 crypto/rsa-pkcs1pad.c     |    5 +++--
 crypto/xts.c              |    2 +-
 include/crypto/algapi.h   |    9 +++++++++
 include/linux/crypto.h    |   11 ++++++++++-
 16 files changed, 66 insertions(+), 31 deletions(-)

Comments

Herbert Xu June 26, 2020, 4:45 a.m. UTC | #1 
On Wed, Jun 17, 2020 at 11:09:28AM -0400, Mikulas Patocka wrote:
>
> Index: linux-2.6/include/linux/crypto.h
> ===================================================================
> --- linux-2.6.orig/include/linux/crypto.h
> +++ linux-2.6/include/linux/crypto.h
> @@ -97,9 +97,18 @@
>  #define CRYPTO_ALG_OPTIONAL_KEY		0x00004000
>  
>  /*
> + * The driver may allocate memory during request processing, so it shouldn't be
> + * used in cases where memory allocation failures aren't acceptable, such as
> + * during block device encryption.
> + */
> +#define CRYPTO_ALG_ALLOCATES_MEMORY	0x00008000
> +
> +/*
>   * Don't trigger module loading
>   */
> -#define CRYPTO_NOLOAD			0x00008000
> +#define CRYPTO_NOLOAD			0x00010000
> +
> +#define CRYPTO_ALG_INHERITED_FLAGS	(CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY)

Any reason why you need to renumber NOLOAD? If not please keep
the existing values.

Thanks,
Mikulas Patocka June 26, 2020, 3:17 p.m. UTC | #2 
On Fri, 26 Jun 2020, Herbert Xu wrote:

> On Wed, Jun 17, 2020 at 11:09:28AM -0400, Mikulas Patocka wrote:
> >
> > Index: linux-2.6/include/linux/crypto.h
> > ===================================================================
> > --- linux-2.6.orig/include/linux/crypto.h
> > +++ linux-2.6/include/linux/crypto.h
> > @@ -97,9 +97,18 @@
> >  #define CRYPTO_ALG_OPTIONAL_KEY		0x00004000
> >  
> >  /*
> > + * The driver may allocate memory during request processing, so it shouldn't be
> > + * used in cases where memory allocation failures aren't acceptable, such as
> > + * during block device encryption.
> > + */
> > +#define CRYPTO_ALG_ALLOCATES_MEMORY	0x00008000
> > +
> > +/*
> >   * Don't trigger module loading
> >   */
> > -#define CRYPTO_NOLOAD			0x00008000
> > +#define CRYPTO_NOLOAD			0x00010000
> > +
> > +#define CRYPTO_ALG_INHERITED_FLAGS	(CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY)
> 
> Any reason why you need to renumber NOLOAD? If not please keep
> the existing values.

There is no hard reason for that. CRYPTO_NOLOAD is a "virtual" flag that 
could be only present in crypto algorithm requests and I thought that the 
intention was that the virtual flags go after real flags. If you don't 
want to change existing flags, there is no problem with that.

Mikulas

> Thanks,
> -- 
> Email: Herbert Xu <herbert@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
>
diff mbox series

Patch

Index: linux-2.6/include/linux/crypto.h
===================================================================
--- linux-2.6.orig/include/linux/crypto.h
+++ linux-2.6/include/linux/crypto.h
@@ -97,9 +97,18 @@ 
 #define CRYPTO_ALG_OPTIONAL_KEY		0x00004000
 
 /*
+ * The driver may allocate memory during request processing, so it shouldn't be
+ * used in cases where memory allocation failures aren't acceptable, such as
+ * during block device encryption.
+ */
+#define CRYPTO_ALG_ALLOCATES_MEMORY	0x00008000
+
+/*
  * Don't trigger module loading
  */
-#define CRYPTO_NOLOAD			0x00008000
+#define CRYPTO_NOLOAD			0x00010000
+
+#define CRYPTO_ALG_INHERITED_FLAGS	(CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY)
 
 /*
  * Transform masks and values (for crt_flags).
Index: linux-2.6/crypto/authenc.c
===================================================================
--- linux-2.6.orig/crypto/authenc.c
+++ linux-2.6/crypto/authenc.c
@@ -388,7 +388,8 @@  static int crypto_authenc_create(struct
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 	if (!inst)
@@ -424,7 +425,7 @@  static int crypto_authenc_create(struct
 		goto err_free_inst;
 
 	inst->alg.base.cra_flags = (auth_base->cra_flags |
-				    enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
+			enc->base.cra_flags) & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
 				      auth_base->cra_priority;
 	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
Index: linux-2.6/crypto/authencesn.c
===================================================================
--- linux-2.6.orig/crypto/authencesn.c
+++ linux-2.6/crypto/authencesn.c
@@ -406,7 +406,8 @@  static int crypto_authenc_esn_create(str
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 	if (!inst)
@@ -438,7 +439,7 @@  static int crypto_authenc_esn_create(str
 		goto err_free_inst;
 
 	inst->alg.base.cra_flags = (auth_base->cra_flags |
-				    enc->base.cra_flags) & CRYPTO_ALG_ASYNC;
+			enc->base.cra_flags) & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = enc->base.cra_priority * 10 +
 				      auth_base->cra_priority;
 	inst->alg.base.cra_blocksize = enc->base.cra_blocksize;
Index: linux-2.6/crypto/ccm.c
===================================================================
--- linux-2.6.orig/crypto/ccm.c
+++ linux-2.6/crypto/ccm.c
@@ -462,7 +462,8 @@  static int crypto_ccm_create_common(stru
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 	if (!inst)
@@ -507,7 +508,7 @@  static int crypto_ccm_create_common(stru
 		     mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 		goto err_free_inst;
 
-	inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = (mac->base.cra_priority +
 				       ctr->base.cra_priority) / 2;
 	inst->alg.base.cra_blocksize = 1;
@@ -759,7 +760,7 @@  static int crypto_rfc4309_create(struct
 	    CRYPTO_MAX_ALG_NAME)
 		goto err_free_inst;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
 	inst->alg.base.cra_blocksize = 1;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
Index: linux-2.6/crypto/chacha20poly1305.c
===================================================================
--- linux-2.6.orig/crypto/chacha20poly1305.c
+++ linux-2.6/crypto/chacha20poly1305.c
@@ -573,7 +573,8 @@  static int chachapoly_create(struct cryp
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 	if (!inst)
@@ -614,7 +615,7 @@  static int chachapoly_create(struct cryp
 		goto err_free_inst;
 
 	inst->alg.base.cra_flags = (chacha->base.cra_flags |
-				    poly->base.cra_flags) & CRYPTO_ALG_ASYNC;
+			poly->base.cra_flags) & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = (chacha->base.cra_priority +
 				       poly->base.cra_priority) / 2;
 	inst->alg.base.cra_blocksize = 1;
Index: linux-2.6/crypto/cryptd.c
===================================================================
--- linux-2.6.orig/crypto/cryptd.c
+++ linux-2.6/crypto/cryptd.c
@@ -396,7 +396,8 @@  static int cryptd_create_skcipher(struct
 		goto err_free_inst;
 
 	inst->alg.base.cra_flags = CRYPTO_ALG_ASYNC |
-				   (alg->base.cra_flags & CRYPTO_ALG_INTERNAL);
+			(alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS) |
+			(alg->base.cra_flags & CRYPTO_ALG_INTERNAL);
 
 	inst->alg.ivsize = crypto_skcipher_alg_ivsize(alg);
 	inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
@@ -663,7 +664,8 @@  static int cryptd_create_hash(struct cry
 
 	inst->alg.halg.base.cra_flags = CRYPTO_ALG_ASYNC |
 		(alg->base.cra_flags & (CRYPTO_ALG_INTERNAL |
-					CRYPTO_ALG_OPTIONAL_KEY));
+					CRYPTO_ALG_OPTIONAL_KEY |
+					CRYPTO_ALG_INHERITED_FLAGS));
 
 	inst->alg.halg.digestsize = alg->digestsize;
 	inst->alg.halg.statesize = alg->statesize;
@@ -849,7 +851,8 @@  static int cryptd_create_aead(struct cry
 		goto err_free_inst;
 
 	inst->alg.base.cra_flags = CRYPTO_ALG_ASYNC |
-				   (alg->base.cra_flags & CRYPTO_ALG_INTERNAL);
+			(alg->base.cra_flags & CRYPTO_ALG_INTERNAL) |
+			(alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS);
 	inst->alg.base.cra_ctxsize = sizeof(struct cryptd_aead_ctx);
 
 	inst->alg.ivsize = crypto_aead_alg_ivsize(alg);
Index: linux-2.6/crypto/ctr.c
===================================================================
--- linux-2.6.orig/crypto/ctr.c
+++ linux-2.6/crypto/ctr.c
@@ -276,6 +276,7 @@  static int crypto_rfc3686_create(struct
 		return -ENOMEM;
 
 	mask = crypto_requires_sync(algt->type, algt->mask) |
+		crypto_requires_nomem(algt->type, algt->mask) |
 		crypto_requires_off(algt->type, algt->mask,
 				    CRYPTO_ALG_NEED_FALLBACK);
 
@@ -310,7 +311,7 @@  static int crypto_rfc3686_create(struct
 	inst->alg.base.cra_blocksize = 1;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 
 	inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
 	inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
Index: linux-2.6/crypto/cts.c
===================================================================
--- linux-2.6.orig/crypto/cts.c
+++ linux-2.6/crypto/cts.c
@@ -337,7 +337,8 @@  static int crypto_cts_create(struct cryp
 	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 	if (!inst)
@@ -364,7 +365,7 @@  static int crypto_cts_create(struct cryp
 	if (err)
 		goto err_free_inst;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
 	inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
Index: linux-2.6/crypto/essiv.c
===================================================================
--- linux-2.6.orig/crypto/essiv.c
+++ linux-2.6/crypto/essiv.c
@@ -468,7 +468,8 @@  static int essiv_create(struct crypto_te
 		return PTR_ERR(shash_name);
 
 	type = algt->type & algt->mask;
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	switch (type) {
 	case CRYPTO_ALG_TYPE_SKCIPHER:
@@ -559,7 +560,7 @@  static int essiv_create(struct crypto_te
 		     hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 		goto out_free_hash;
 
-	base->cra_flags		= block_base->cra_flags & CRYPTO_ALG_ASYNC;
+	base->cra_flags		= block_base->cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	base->cra_blocksize	= block_base->cra_blocksize;
 	base->cra_ctxsize	= sizeof(struct essiv_tfm_ctx);
 	base->cra_alignmask	= block_base->cra_alignmask;
Index: linux-2.6/crypto/gcm.c
===================================================================
--- linux-2.6.orig/crypto/gcm.c
+++ linux-2.6/crypto/gcm.c
@@ -593,7 +593,8 @@  static int crypto_gcm_create_common(stru
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 	if (!inst)
@@ -636,7 +637,7 @@  static int crypto_gcm_create_common(stru
 		goto err_free_inst;
 
 	inst->alg.base.cra_flags = (ghash->base.cra_flags |
-				    ctr->base.cra_flags) & CRYPTO_ALG_ASYNC;
+			ctr->base.cra_flags) & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = (ghash->base.cra_priority +
 				       ctr->base.cra_priority) / 2;
 	inst->alg.base.cra_blocksize = 1;
@@ -849,7 +850,8 @@  static int crypto_rfc4106_create(struct
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 	if (!inst)
@@ -882,7 +884,7 @@  static int crypto_rfc4106_create(struct
 	    CRYPTO_MAX_ALG_NAME)
 		goto err_free_inst;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
 	inst->alg.base.cra_blocksize = 1;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
@@ -1071,7 +1073,8 @@  static int crypto_rfc4543_create(struct
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 	if (!inst)
@@ -1104,7 +1107,7 @@  static int crypto_rfc4543_create(struct
 	    CRYPTO_MAX_ALG_NAME)
 		goto err_free_inst;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
 	inst->alg.base.cra_blocksize = 1;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
Index: linux-2.6/crypto/geniv.c
===================================================================
--- linux-2.6.orig/crypto/geniv.c
+++ linux-2.6/crypto/geniv.c
@@ -64,6 +64,7 @@  struct aead_instance *aead_geniv_alloc(s
 
 	/* Ignore async algorithms if necessary. */
 	mask |= crypto_requires_sync(algt->type, algt->mask);
+	mask |= crypto_requires_nomem(algt->type, algt->mask);
 
 	err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
 			       crypto_attr_alg_name(tb[1]), type, mask);
@@ -89,7 +90,7 @@  struct aead_instance *aead_geniv_alloc(s
 	    CRYPTO_MAX_ALG_NAME)
 		goto err_free_inst;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
 	inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
Index: linux-2.6/crypto/lrw.c
===================================================================
--- linux-2.6.orig/crypto/lrw.c
+++ linux-2.6/crypto/lrw.c
@@ -311,7 +311,8 @@  static int create(struct crypto_template
 	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	cipher_name = crypto_attr_alg_name(tb[1]);
 	if (IS_ERR(cipher_name))
@@ -379,7 +380,7 @@  static int create(struct crypto_template
 	} else
 		goto err_free_inst;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
 	inst->alg.base.cra_blocksize = LRW_BLOCK_SIZE;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask |
Index: linux-2.6/crypto/rsa-pkcs1pad.c
===================================================================
--- linux-2.6.orig/crypto/rsa-pkcs1pad.c
+++ linux-2.6/crypto/rsa-pkcs1pad.c
@@ -611,7 +611,8 @@  static int pkcs1pad_create(struct crypto
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 	if (!inst)
@@ -658,7 +659,7 @@  static int pkcs1pad_create(struct crypto
 			goto err_free_inst;
 	}
 
-	inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
 	inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
 
Index: linux-2.6/crypto/xts.c
===================================================================
--- linux-2.6.orig/crypto/xts.c
+++ linux-2.6/crypto/xts.c
@@ -415,7 +415,7 @@  static int create(struct crypto_template
 	} else
 		goto err_free_inst;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
 	inst->alg.base.cra_blocksize = XTS_BLOCK_SIZE;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask |
Index: linux-2.6/include/crypto/algapi.h
===================================================================
--- linux-2.6.orig/include/crypto/algapi.h
+++ linux-2.6/include/crypto/algapi.h
@@ -247,6 +247,15 @@  static inline int crypto_requires_sync(u
 	return crypto_requires_off(type, mask, CRYPTO_ALG_ASYNC);
 }
 
+/*
+ * Returns CRYPTO_ALG_ALLOCATES_MEMORY if type/mask requires the use of drivers
+ * that don't allocate memory. Otherwise returns zero.
+ */
+static inline int crypto_requires_nomem(u32 type, u32 mask)
+{
+	return crypto_requires_off(type, mask, CRYPTO_ALG_ALLOCATES_MEMORY);
+}
+
 noinline unsigned long __crypto_memneq(const void *a, const void *b, size_t size);
 
 /**
Index: linux-2.6/crypto/adiantum.c
===================================================================
--- linux-2.6.orig/crypto/adiantum.c
+++ linux-2.6/crypto/adiantum.c
@@ -507,7 +507,8 @@  static int adiantum_create(struct crypto
 	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
 		return -EINVAL;
 
-	mask = crypto_requires_sync(algt->type, algt->mask);
+	mask = crypto_requires_sync(algt->type, algt->mask) |
+	       crypto_requires_nomem(algt->type, algt->mask);
 
 	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 	if (!inst)