[dm-devel] fix blk_crypto_profile liftetime

[dm-devel] fix blk_crypto_profile liftetime

[Christoph Hellwig]

Hi all,

the newly added blk-crypto sysfs support does not seem to keep the
blk_crypto_profile lifetimes aligned to what sysfs expects.

This was found by code inspection only and is completely untested.

Diffstat:
 b/Documentation/block/inline-encryption.rst |   10 -
 b/block/Makefile                            |    3 
 b/block/blk-crypto-fallback.c               |   20 +-
 b/block/blk-crypto-profile.c                |  263 ++++++++++++++++++++++------
 b/drivers/md/dm-table.c                     |   28 --
 b/drivers/mmc/core/crypto.c                 |    4 
 b/drivers/mmc/host/cqhci-crypto.c           |   16 -
 b/drivers/scsi/ufs/ufshcd-crypto.c          |   31 +--
 b/drivers/scsi/ufs/ufshcd.h                 |    2 
 b/include/linux/blk-crypto-profile.h        |   19 +-
 b/include/linux/blkdev.h                    |    1 
 b/include/linux/mmc/host.h                  |    2 
 block/blk-crypto-sysfs.c                    |  172 ------------------
 13 files changed, 265 insertions(+), 306 deletions(-)

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fix blk_crypto_profile liftetime

[Christoph Hellwig]

Hi all,

the newly added blk-crypto sysfs support does not seem to keep the
blk_crypto_profile lifetimes aligned to what sysfs expects.

This was found by code inspection only and is completely untested.

Diffstat:
 b/Documentation/block/inline-encryption.rst |   10 -
 b/block/Makefile                            |    3 
 b/block/blk-crypto-fallback.c               |   20 +-
 b/block/blk-crypto-profile.c                |  263 ++++++++++++++++++++++------
 b/drivers/md/dm-table.c                     |   28 --
 b/drivers/mmc/core/crypto.c                 |    4 
 b/drivers/mmc/host/cqhci-crypto.c           |   16 -
 b/drivers/scsi/ufs/ufshcd-crypto.c          |   31 +--
 b/drivers/scsi/ufs/ufshcd.h                 |    2 
 b/include/linux/blk-crypto-profile.h        |   19 +-
 b/include/linux/blkdev.h                    |    1 
 b/include/linux/mmc/host.h                  |    2 
 block/blk-crypto-sysfs.c                    |  172 ------------------
 13 files changed, 265 insertions(+), 306 deletions(-)

[dm-devel] [PATCH 1/2] blk-crypto: merge blk-crypto-sysfs.c into blk-crypto-profile.c

[Christoph Hellwig]

Merge blk-crypto-sysfs.c into blk-crypto-profile.c in preparation of
fixing the kobject lifetimes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/Makefile             |   3 +-
 block/blk-crypto-profile.c | 164 ++++++++++++++++++++++++++++++++++-
 block/blk-crypto-sysfs.c   | 172 -------------------------------------
 3 files changed, 164 insertions(+), 175 deletions(-)
 delete mode 100644 block/blk-crypto-sysfs.c

diff --git a/block/Makefile b/block/Makefile
index 3950ecbc5c263..f38eaa6129296 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -36,7 +36,6 @@ obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
 obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
 obj-$(CONFIG_BLK_PM)		+= blk-pm.o
-obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o \
-					   blk-crypto-sysfs.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o
 obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK)	+= blk-crypto-fallback.o
 obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED)	+= holder.o
diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c
index 96c511967386d..4f444323cb491 100644
--- a/block/blk-crypto-profile.c
+++ b/block/blk-crypto-profile.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright 2019 Google LLC
+ * Copyright 2019-2021 Google LLC
  */
 
 /**
@@ -32,6 +32,7 @@
 #include <linux/wait.h>
 #include <linux/blkdev.h>
 #include <linux/blk-integrity.h>
+#include "blk-crypto-internal.h"
 
 struct blk_crypto_keyslot {
 	atomic_t slot_refs;
@@ -41,6 +42,150 @@ struct blk_crypto_keyslot {
 	struct blk_crypto_profile *profile;
 };
 
+struct blk_crypto_kobj {
+	struct kobject kobj;
+	struct blk_crypto_profile *profile;
+};
+
+struct blk_crypto_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct blk_crypto_profile *profile,
+			struct blk_crypto_attr *attr, char *page);
+};
+
+static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
+{
+	return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
+}
+
+static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
+{
+	return container_of(attr, struct blk_crypto_attr, attr);
+}
+
+static ssize_t max_dun_bits_show(struct blk_crypto_profile *profile,
+				 struct blk_crypto_attr *attr, char *page)
+{
+	return sysfs_emit(page, "%u\n", 8 * profile->max_dun_bytes_supported);
+}
+
+static ssize_t num_keyslots_show(struct blk_crypto_profile *profile,
+				 struct blk_crypto_attr *attr, char *page)
+{
+	return sysfs_emit(page, "%u\n", profile->num_slots);
+}
+
+#define BLK_CRYPTO_RO_ATTR(_name) \
+	static struct blk_crypto_attr _name##_attr = __ATTR_RO(_name)
+
+BLK_CRYPTO_RO_ATTR(max_dun_bits);
+BLK_CRYPTO_RO_ATTR(num_keyslots);
+
+static struct attribute *blk_crypto_attrs[] = {
+	&max_dun_bits_attr.attr,
+	&num_keyslots_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group blk_crypto_attr_group = {
+	.attrs = blk_crypto_attrs,
+};
+
+/*
+ * The encryption mode attributes.  To avoid hard-coding the list of encryption
+ * modes, these are initialized at boot time by blk_crypto_sysfs_init().
+ */
+static struct blk_crypto_attr __blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX];
+static struct attribute *blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX + 1];
+
+static umode_t blk_crypto_mode_is_visible(struct kobject *kobj,
+					  struct attribute *attr, int n)
+{
+	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
+	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
+	int mode_num = a - __blk_crypto_mode_attrs;
+
+	if (profile->modes_supported[mode_num])
+		return 0444;
+	return 0;
+}
+
+static ssize_t blk_crypto_mode_show(struct blk_crypto_profile *profile,
+				    struct blk_crypto_attr *attr, char *page)
+{
+	int mode_num = attr - __blk_crypto_mode_attrs;
+
+	return sysfs_emit(page, "0x%x\n", profile->modes_supported[mode_num]);
+}
+
+static const struct attribute_group blk_crypto_modes_attr_group = {
+	.name = "modes",
+	.attrs = blk_crypto_mode_attrs,
+	.is_visible = blk_crypto_mode_is_visible,
+};
+
+static const struct attribute_group *blk_crypto_attr_groups[] = {
+	&blk_crypto_attr_group,
+	&blk_crypto_modes_attr_group,
+	NULL,
+};
+
+static ssize_t blk_crypto_attr_show(struct kobject *kobj,
+				    struct attribute *attr, char *page)
+{
+	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
+	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
+
+	return a->show(profile, a, page);
+}
+
+static const struct sysfs_ops blk_crypto_attr_ops = {
+	.show = blk_crypto_attr_show,
+};
+
+static void blk_crypto_release(struct kobject *kobj)
+{
+	kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
+}
+
+static struct kobj_type blk_crypto_ktype = {
+	.default_groups = blk_crypto_attr_groups,
+	.sysfs_ops	= &blk_crypto_attr_ops,
+	.release	= blk_crypto_release,
+};
+
+/*
+ * If the request_queue has a blk_crypto_profile, create the "crypto"
+ * subdirectory in sysfs (/sys/block/$disk/queue/crypto/).
+ */
+int blk_crypto_sysfs_register(struct request_queue *q)
+{
+	struct blk_crypto_kobj *obj;
+	int err;
+
+	if (!q->crypto_profile)
+		return 0;
+
+	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	if (!obj)
+		return -ENOMEM;
+	obj->profile = q->crypto_profile;
+
+	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
+				   "crypto");
+	if (err) {
+		kobject_put(&obj->kobj);
+		return err;
+	}
+	q->crypto_kobject = &obj->kobj;
+	return 0;
+}
+
+void blk_crypto_sysfs_unregister(struct request_queue *q)
+{
+	kobject_put(q->crypto_kobject);
+}
+
 static inline void blk_crypto_hw_enter(struct blk_crypto_profile *profile)
 {
 	/*
@@ -558,3 +703,20 @@ void blk_crypto_update_capabilities(struct blk_crypto_profile *dst,
 	dst->max_dun_bytes_supported = src->max_dun_bytes_supported;
 }
 EXPORT_SYMBOL_GPL(blk_crypto_update_capabilities);
+
+static int __init blk_crypto_sysfs_init(void)
+{
+	int i;
+
+	BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
+	for (i = 1; i < BLK_ENCRYPTION_MODE_MAX; i++) {
+		struct blk_crypto_attr *attr = &__blk_crypto_mode_attrs[i];
+
+		attr->attr.name = blk_crypto_modes[i].name;
+		attr->attr.mode = 0444;
+		attr->show = blk_crypto_mode_show;
+		blk_crypto_mode_attrs[i - 1] = &attr->attr;
+	}
+	return 0;
+}
+subsys_initcall(blk_crypto_sysfs_init);
diff --git a/block/blk-crypto-sysfs.c b/block/blk-crypto-sysfs.c
deleted file mode 100644
index fd93bd2f33b75..0000000000000
--- a/block/blk-crypto-sysfs.c
+++ /dev/null
@@ -1,172 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright 2021 Google LLC
- *
- * sysfs support for blk-crypto.  This file contains the code which exports the
- * crypto capabilities of devices via /sys/block/$disk/queue/crypto/.
- */
-
-#include <linux/blk-crypto-profile.h>
-
-#include "blk-crypto-internal.h"
-
-struct blk_crypto_kobj {
-	struct kobject kobj;
-	struct blk_crypto_profile *profile;
-};
-
-struct blk_crypto_attr {
-	struct attribute attr;
-	ssize_t (*show)(struct blk_crypto_profile *profile,
-			struct blk_crypto_attr *attr, char *page);
-};
-
-static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
-{
-	return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
-}
-
-static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
-{
-	return container_of(attr, struct blk_crypto_attr, attr);
-}
-
-static ssize_t max_dun_bits_show(struct blk_crypto_profile *profile,
-				 struct blk_crypto_attr *attr, char *page)
-{
-	return sysfs_emit(page, "%u\n", 8 * profile->max_dun_bytes_supported);
-}
-
-static ssize_t num_keyslots_show(struct blk_crypto_profile *profile,
-				 struct blk_crypto_attr *attr, char *page)
-{
-	return sysfs_emit(page, "%u\n", profile->num_slots);
-}
-
-#define BLK_CRYPTO_RO_ATTR(_name) \
-	static struct blk_crypto_attr _name##_attr = __ATTR_RO(_name)
-
-BLK_CRYPTO_RO_ATTR(max_dun_bits);
-BLK_CRYPTO_RO_ATTR(num_keyslots);
-
-static struct attribute *blk_crypto_attrs[] = {
-	&max_dun_bits_attr.attr,
-	&num_keyslots_attr.attr,
-	NULL,
-};
-
-static const struct attribute_group blk_crypto_attr_group = {
-	.attrs = blk_crypto_attrs,
-};
-
-/*
- * The encryption mode attributes.  To avoid hard-coding the list of encryption
- * modes, these are initialized at boot time by blk_crypto_sysfs_init().
- */
-static struct blk_crypto_attr __blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX];
-static struct attribute *blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX + 1];
-
-static umode_t blk_crypto_mode_is_visible(struct kobject *kobj,
-					  struct attribute *attr, int n)
-{
-	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
-	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
-	int mode_num = a - __blk_crypto_mode_attrs;
-
-	if (profile->modes_supported[mode_num])
-		return 0444;
-	return 0;
-}
-
-static ssize_t blk_crypto_mode_show(struct blk_crypto_profile *profile,
-				    struct blk_crypto_attr *attr, char *page)
-{
-	int mode_num = attr - __blk_crypto_mode_attrs;
-
-	return sysfs_emit(page, "0x%x\n", profile->modes_supported[mode_num]);
-}
-
-static const struct attribute_group blk_crypto_modes_attr_group = {
-	.name = "modes",
-	.attrs = blk_crypto_mode_attrs,
-	.is_visible = blk_crypto_mode_is_visible,
-};
-
-static const struct attribute_group *blk_crypto_attr_groups[] = {
-	&blk_crypto_attr_group,
-	&blk_crypto_modes_attr_group,
-	NULL,
-};
-
-static ssize_t blk_crypto_attr_show(struct kobject *kobj,
-				    struct attribute *attr, char *page)
-{
-	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
-	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
-
-	return a->show(profile, a, page);
-}
-
-static const struct sysfs_ops blk_crypto_attr_ops = {
-	.show = blk_crypto_attr_show,
-};
-
-static void blk_crypto_release(struct kobject *kobj)
-{
-	kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
-}
-
-static struct kobj_type blk_crypto_ktype = {
-	.default_groups = blk_crypto_attr_groups,
-	.sysfs_ops	= &blk_crypto_attr_ops,
-	.release	= blk_crypto_release,
-};
-
-/*
- * If the request_queue has a blk_crypto_profile, create the "crypto"
- * subdirectory in sysfs (/sys/block/$disk/queue/crypto/).
- */
-int blk_crypto_sysfs_register(struct request_queue *q)
-{
-	struct blk_crypto_kobj *obj;
-	int err;
-
-	if (!q->crypto_profile)
-		return 0;
-
-	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
-	if (!obj)
-		return -ENOMEM;
-	obj->profile = q->crypto_profile;
-
-	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
-				   "crypto");
-	if (err) {
-		kobject_put(&obj->kobj);
-		return err;
-	}
-	q->crypto_kobject = &obj->kobj;
-	return 0;
-}
-
-void blk_crypto_sysfs_unregister(struct request_queue *q)
-{
-	kobject_put(q->crypto_kobject);
-}
-
-static int __init blk_crypto_sysfs_init(void)
-{
-	int i;
-
-	BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
-	for (i = 1; i < BLK_ENCRYPTION_MODE_MAX; i++) {
-		struct blk_crypto_attr *attr = &__blk_crypto_mode_attrs[i];
-
-		attr->attr.name = blk_crypto_modes[i].name;
-		attr->attr.mode = 0444;
-		attr->show = blk_crypto_mode_show;
-		blk_crypto_mode_attrs[i - 1] = &attr->attr;
-	}
-	return 0;
-}
-subsys_initcall(blk_crypto_sysfs_init);
-- 
2.30.2

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[PATCH 1/2] blk-crypto: merge blk-crypto-sysfs.c into blk-crypto-profile.c

[Christoph Hellwig]

Merge blk-crypto-sysfs.c into blk-crypto-profile.c in preparation of
fixing the kobject lifetimes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/Makefile             |   3 +-
 block/blk-crypto-profile.c | 164 ++++++++++++++++++++++++++++++++++-
 block/blk-crypto-sysfs.c   | 172 -------------------------------------
 3 files changed, 164 insertions(+), 175 deletions(-)
 delete mode 100644 block/blk-crypto-sysfs.c

diff --git a/block/Makefile b/block/Makefile
index 3950ecbc5c263..f38eaa6129296 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -36,7 +36,6 @@ obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
 obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
 obj-$(CONFIG_BLK_PM)		+= blk-pm.o
-obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o \
-					   blk-crypto-sysfs.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o
 obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK)	+= blk-crypto-fallback.o
 obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED)	+= holder.o
diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c
index 96c511967386d..4f444323cb491 100644
--- a/block/blk-crypto-profile.c
+++ b/block/blk-crypto-profile.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright 2019 Google LLC
+ * Copyright 2019-2021 Google LLC
  */
 
 /**
@@ -32,6 +32,7 @@
 #include <linux/wait.h>
 #include <linux/blkdev.h>
 #include <linux/blk-integrity.h>
+#include "blk-crypto-internal.h"
 
 struct blk_crypto_keyslot {
 	atomic_t slot_refs;
@@ -41,6 +42,150 @@ struct blk_crypto_keyslot {
 	struct blk_crypto_profile *profile;
 };
 
+struct blk_crypto_kobj {
+	struct kobject kobj;
+	struct blk_crypto_profile *profile;
+};
+
+struct blk_crypto_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct blk_crypto_profile *profile,
+			struct blk_crypto_attr *attr, char *page);
+};
+
+static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
+{
+	return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
+}
+
+static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
+{
+	return container_of(attr, struct blk_crypto_attr, attr);
+}
+
+static ssize_t max_dun_bits_show(struct blk_crypto_profile *profile,
+				 struct blk_crypto_attr *attr, char *page)
+{
+	return sysfs_emit(page, "%u\n", 8 * profile->max_dun_bytes_supported);
+}
+
+static ssize_t num_keyslots_show(struct blk_crypto_profile *profile,
+				 struct blk_crypto_attr *attr, char *page)
+{
+	return sysfs_emit(page, "%u\n", profile->num_slots);
+}
+
+#define BLK_CRYPTO_RO_ATTR(_name) \
+	static struct blk_crypto_attr _name##_attr = __ATTR_RO(_name)
+
+BLK_CRYPTO_RO_ATTR(max_dun_bits);
+BLK_CRYPTO_RO_ATTR(num_keyslots);
+
+static struct attribute *blk_crypto_attrs[] = {
+	&max_dun_bits_attr.attr,
+	&num_keyslots_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group blk_crypto_attr_group = {
+	.attrs = blk_crypto_attrs,
+};
+
+/*
+ * The encryption mode attributes.  To avoid hard-coding the list of encryption
+ * modes, these are initialized at boot time by blk_crypto_sysfs_init().
+ */
+static struct blk_crypto_attr __blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX];
+static struct attribute *blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX + 1];
+
+static umode_t blk_crypto_mode_is_visible(struct kobject *kobj,
+					  struct attribute *attr, int n)
+{
+	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
+	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
+	int mode_num = a - __blk_crypto_mode_attrs;
+
+	if (profile->modes_supported[mode_num])
+		return 0444;
+	return 0;
+}
+
+static ssize_t blk_crypto_mode_show(struct blk_crypto_profile *profile,
+				    struct blk_crypto_attr *attr, char *page)
+{
+	int mode_num = attr - __blk_crypto_mode_attrs;
+
+	return sysfs_emit(page, "0x%x\n", profile->modes_supported[mode_num]);
+}
+
+static const struct attribute_group blk_crypto_modes_attr_group = {
+	.name = "modes",
+	.attrs = blk_crypto_mode_attrs,
+	.is_visible = blk_crypto_mode_is_visible,
+};
+
+static const struct attribute_group *blk_crypto_attr_groups[] = {
+	&blk_crypto_attr_group,
+	&blk_crypto_modes_attr_group,
+	NULL,
+};
+
+static ssize_t blk_crypto_attr_show(struct kobject *kobj,
+				    struct attribute *attr, char *page)
+{
+	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
+	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
+
+	return a->show(profile, a, page);
+}
+
+static const struct sysfs_ops blk_crypto_attr_ops = {
+	.show = blk_crypto_attr_show,
+};
+
+static void blk_crypto_release(struct kobject *kobj)
+{
+	kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
+}
+
+static struct kobj_type blk_crypto_ktype = {
+	.default_groups = blk_crypto_attr_groups,
+	.sysfs_ops	= &blk_crypto_attr_ops,
+	.release	= blk_crypto_release,
+};
+
+/*
+ * If the request_queue has a blk_crypto_profile, create the "crypto"
+ * subdirectory in sysfs (/sys/block/$disk/queue/crypto/).
+ */
+int blk_crypto_sysfs_register(struct request_queue *q)
+{
+	struct blk_crypto_kobj *obj;
+	int err;
+
+	if (!q->crypto_profile)
+		return 0;
+
+	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	if (!obj)
+		return -ENOMEM;
+	obj->profile = q->crypto_profile;
+
+	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
+				   "crypto");
+	if (err) {
+		kobject_put(&obj->kobj);
+		return err;
+	}
+	q->crypto_kobject = &obj->kobj;
+	return 0;
+}
+
+void blk_crypto_sysfs_unregister(struct request_queue *q)
+{
+	kobject_put(q->crypto_kobject);
+}
+
 static inline void blk_crypto_hw_enter(struct blk_crypto_profile *profile)
 {
 	/*
@@ -558,3 +703,20 @@ void blk_crypto_update_capabilities(struct blk_crypto_profile *dst,
 	dst->max_dun_bytes_supported = src->max_dun_bytes_supported;
 }
 EXPORT_SYMBOL_GPL(blk_crypto_update_capabilities);
+
+static int __init blk_crypto_sysfs_init(void)
+{
+	int i;
+
+	BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
+	for (i = 1; i < BLK_ENCRYPTION_MODE_MAX; i++) {
+		struct blk_crypto_attr *attr = &__blk_crypto_mode_attrs[i];
+
+		attr->attr.name = blk_crypto_modes[i].name;
+		attr->attr.mode = 0444;
+		attr->show = blk_crypto_mode_show;
+		blk_crypto_mode_attrs[i - 1] = &attr->attr;
+	}
+	return 0;
+}
+subsys_initcall(blk_crypto_sysfs_init);
diff --git a/block/blk-crypto-sysfs.c b/block/blk-crypto-sysfs.c
deleted file mode 100644
index fd93bd2f33b75..0000000000000
--- a/block/blk-crypto-sysfs.c
+++ /dev/null
@@ -1,172 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright 2021 Google LLC
- *
- * sysfs support for blk-crypto.  This file contains the code which exports the
- * crypto capabilities of devices via /sys/block/$disk/queue/crypto/.
- */
-
-#include <linux/blk-crypto-profile.h>
-
-#include "blk-crypto-internal.h"
-
-struct blk_crypto_kobj {
-	struct kobject kobj;
-	struct blk_crypto_profile *profile;
-};
-
-struct blk_crypto_attr {
-	struct attribute attr;
-	ssize_t (*show)(struct blk_crypto_profile *profile,
-			struct blk_crypto_attr *attr, char *page);
-};
-
-static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
-{
-	return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
-}
-
-static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
-{
-	return container_of(attr, struct blk_crypto_attr, attr);
-}
-
-static ssize_t max_dun_bits_show(struct blk_crypto_profile *profile,
-				 struct blk_crypto_attr *attr, char *page)
-{
-	return sysfs_emit(page, "%u\n", 8 * profile->max_dun_bytes_supported);
-}
-
-static ssize_t num_keyslots_show(struct blk_crypto_profile *profile,
-				 struct blk_crypto_attr *attr, char *page)
-{
-	return sysfs_emit(page, "%u\n", profile->num_slots);
-}
-
-#define BLK_CRYPTO_RO_ATTR(_name) \
-	static struct blk_crypto_attr _name##_attr = __ATTR_RO(_name)
-
-BLK_CRYPTO_RO_ATTR(max_dun_bits);
-BLK_CRYPTO_RO_ATTR(num_keyslots);
-
-static struct attribute *blk_crypto_attrs[] = {
-	&max_dun_bits_attr.attr,
-	&num_keyslots_attr.attr,
-	NULL,
-};
-
-static const struct attribute_group blk_crypto_attr_group = {
-	.attrs = blk_crypto_attrs,
-};
-
-/*
- * The encryption mode attributes.  To avoid hard-coding the list of encryption
- * modes, these are initialized at boot time by blk_crypto_sysfs_init().
- */
-static struct blk_crypto_attr __blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX];
-static struct attribute *blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX + 1];
-
-static umode_t blk_crypto_mode_is_visible(struct kobject *kobj,
-					  struct attribute *attr, int n)
-{
-	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
-	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
-	int mode_num = a - __blk_crypto_mode_attrs;
-
-	if (profile->modes_supported[mode_num])
-		return 0444;
-	return 0;
-}
-
-static ssize_t blk_crypto_mode_show(struct blk_crypto_profile *profile,
-				    struct blk_crypto_attr *attr, char *page)
-{
-	int mode_num = attr - __blk_crypto_mode_attrs;
-
-	return sysfs_emit(page, "0x%x\n", profile->modes_supported[mode_num]);
-}
-
-static const struct attribute_group blk_crypto_modes_attr_group = {
-	.name = "modes",
-	.attrs = blk_crypto_mode_attrs,
-	.is_visible = blk_crypto_mode_is_visible,
-};
-
-static const struct attribute_group *blk_crypto_attr_groups[] = {
-	&blk_crypto_attr_group,
-	&blk_crypto_modes_attr_group,
-	NULL,
-};
-
-static ssize_t blk_crypto_attr_show(struct kobject *kobj,
-				    struct attribute *attr, char *page)
-{
-	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
-	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
-
-	return a->show(profile, a, page);
-}
-
-static const struct sysfs_ops blk_crypto_attr_ops = {
-	.show = blk_crypto_attr_show,
-};
-
-static void blk_crypto_release(struct kobject *kobj)
-{
-	kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
-}
-
-static struct kobj_type blk_crypto_ktype = {
-	.default_groups = blk_crypto_attr_groups,
-	.sysfs_ops	= &blk_crypto_attr_ops,
-	.release	= blk_crypto_release,
-};
-
-/*
- * If the request_queue has a blk_crypto_profile, create the "crypto"
- * subdirectory in sysfs (/sys/block/$disk/queue/crypto/).
- */
-int blk_crypto_sysfs_register(struct request_queue *q)
-{
-	struct blk_crypto_kobj *obj;
-	int err;
-
-	if (!q->crypto_profile)
-		return 0;
-
-	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
-	if (!obj)
-		return -ENOMEM;
-	obj->profile = q->crypto_profile;
-
-	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
-				   "crypto");
-	if (err) {
-		kobject_put(&obj->kobj);
-		return err;
-	}
-	q->crypto_kobject = &obj->kobj;
-	return 0;
-}
-
-void blk_crypto_sysfs_unregister(struct request_queue *q)
-{
-	kobject_put(q->crypto_kobject);
-}
-
-static int __init blk_crypto_sysfs_init(void)
-{
-	int i;
-
-	BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
-	for (i = 1; i < BLK_ENCRYPTION_MODE_MAX; i++) {
-		struct blk_crypto_attr *attr = &__blk_crypto_mode_attrs[i];
-
-		attr->attr.name = blk_crypto_modes[i].name;
-		attr->attr.mode = 0444;
-		attr->show = blk_crypto_mode_show;
-		blk_crypto_mode_attrs[i - 1] = &attr->attr;
-	}
-	return 0;
-}
-subsys_initcall(blk_crypto_sysfs_init);
-- 
2.30.2

[dm-devel] [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Christoph Hellwig]

Once the blk_crypto_profile is exposed in sysfs it needs to stay alive
as long as sysfs accesses are possibly pending.  Ensure that by removing
the blk_crypto_kobj wrapper and just embedding the kobject into the
actual blk_crypto_profile.  This requires the blk_crypto_profile
structure to be dynamically allocated, which in turn requires a private
data pointer for driver use.

Fixes: 20f01f163203 ("blk-crypto: show crypto capabilities in sysfs")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 Documentation/block/inline-encryption.rst |  10 +-
 block/blk-crypto-fallback.c               |  20 +--
 block/blk-crypto-profile.c                | 143 ++++++++++------------
 drivers/md/dm-table.c                     |  28 +----
 drivers/mmc/core/crypto.c                 |   4 +-
 drivers/mmc/host/cqhci-crypto.c           |  16 ++-
 drivers/scsi/ufs/ufshcd-crypto.c          |  31 ++---
 drivers/scsi/ufs/ufshcd.h                 |   2 +-
 include/linux/blk-crypto-profile.h        |  19 +--
 include/linux/blkdev.h                    |   1 -
 include/linux/mmc/host.h                  |   2 +-
 11 files changed, 123 insertions(+), 153 deletions(-)

diff --git a/Documentation/block/inline-encryption.rst b/Documentation/block/inline-encryption.rst
index 4d151fbe20583..0d740b0f9faf3 100644
--- a/Documentation/block/inline-encryption.rst
+++ b/Documentation/block/inline-encryption.rst
@@ -230,8 +230,8 @@ API presented to device drivers
 
 A device driver that wants to support inline encryption must set up a
 blk_crypto_profile in the request_queue of its device.  To do this, it first
-must call ``blk_crypto_profile_init()`` (or its resource-managed variant
-``devm_blk_crypto_profile_init()``), providing the number of keyslots.
+must call ``blk_crypto_profile_alloc()`` (or its resource-managed variant
+``devm_blk_crypto_profile_alloc()``), providing the number of keyslots.
 
 Next, it must advertise its crypto capabilities by setting fields in the
 blk_crypto_profile, e.g. ``modes_supported`` and ``max_dun_bytes_supported``.
@@ -259,9 +259,9 @@ If there are situations where the inline encryption hardware loses the contents
 of its keyslots, e.g. device resets, the driver must handle reprogramming the
 keyslots.  To do this, the driver may call ``blk_crypto_reprogram_all_keys()``.
 
-Finally, if the driver used ``blk_crypto_profile_init()`` instead of
-``devm_blk_crypto_profile_init()``, then it is responsible for calling
-``blk_crypto_profile_destroy()`` when the crypto profile is no longer needed.
+Finally, if the driver used ``blk_crypto_profile_alloc()`` instead of
+``devm_blk_crypto_profile_alloc()``, then it is responsible for calling
+``blk_crypto_profile_put()`` when the crypto profile is no longer needed.
 
 Layered Devices
 ===============
diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
index 5d1aa5b1d30a1..729974028e448 100644
--- a/block/blk-crypto-fallback.c
+++ b/block/blk-crypto-fallback.c
@@ -78,7 +78,7 @@ static struct blk_crypto_fallback_keyslot {
 	struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
 } *blk_crypto_keyslots;
 
-static struct blk_crypto_profile blk_crypto_fallback_profile;
+static struct blk_crypto_profile *blk_crypto_fallback_profile;
 static struct workqueue_struct *blk_crypto_wq;
 static mempool_t *blk_crypto_bounce_page_pool;
 static struct bio_set crypto_bio_split;
@@ -293,7 +293,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
 	 * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
 	 * this bio's algorithm and key.
 	 */
-	blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
+	blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
 					bc->bc_key, &slot);
 	if (blk_st != BLK_STS_OK) {
 		src_bio->bi_status = blk_st;
@@ -396,7 +396,7 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
 	 * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
 	 * this bio's algorithm and key.
 	 */
-	blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
+	blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
 					bc->bc_key, &slot);
 	if (blk_st != BLK_STS_OK) {
 		bio->bi_status = blk_st;
@@ -500,7 +500,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
 		return false;
 	}
 
-	if (!__blk_crypto_cfg_supported(&blk_crypto_fallback_profile,
+	if (!__blk_crypto_cfg_supported(blk_crypto_fallback_profile,
 					&bc->bc_key->crypto_cfg)) {
 		bio->bi_status = BLK_STS_NOTSUPP;
 		return false;
@@ -527,7 +527,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
 
 int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
 {
-	return __blk_crypto_evict_key(&blk_crypto_fallback_profile, key);
+	return __blk_crypto_evict_key(blk_crypto_fallback_profile, key);
 }
 
 static bool blk_crypto_fallback_inited;
@@ -535,7 +535,7 @@ static int blk_crypto_fallback_init(void)
 {
 	int i;
 	int err;
-	struct blk_crypto_profile *profile = &blk_crypto_fallback_profile;
+	struct blk_crypto_profile *profile;
 
 	if (blk_crypto_fallback_inited)
 		return 0;
@@ -546,10 +546,10 @@ static int blk_crypto_fallback_init(void)
 	if (err)
 		goto out;
 
-	err = blk_crypto_profile_init(profile, blk_crypto_num_keyslots);
-	if (err)
-		goto fail_free_bioset;
 	err = -ENOMEM;
+	profile = blk_crypto_profile_alloc(blk_crypto_num_keyslots);
+	if (!profile)
+		goto fail_free_bioset;
 
 	profile->ll_ops = blk_crypto_fallback_ll_ops;
 	profile->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
@@ -598,7 +598,7 @@ static int blk_crypto_fallback_init(void)
 fail_free_wq:
 	destroy_workqueue(blk_crypto_wq);
 fail_destroy_profile:
-	blk_crypto_profile_destroy(profile);
+	blk_crypto_profile_put(profile);
 fail_free_bioset:
 	bioset_exit(&crypto_bio_split);
 out:
diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c
index 4f444323cb491..e4e14322d2f2e 100644
--- a/block/blk-crypto-profile.c
+++ b/block/blk-crypto-profile.c
@@ -42,11 +42,6 @@ struct blk_crypto_keyslot {
 	struct blk_crypto_profile *profile;
 };
 
-struct blk_crypto_kobj {
-	struct kobject kobj;
-	struct blk_crypto_profile *profile;
-};
-
 struct blk_crypto_attr {
 	struct attribute attr;
 	ssize_t (*show)(struct blk_crypto_profile *profile,
@@ -55,7 +50,7 @@ struct blk_crypto_attr {
 
 static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
 {
-	return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
+	return container_of(kobj, struct blk_crypto_profile, kobj);
 }
 
 static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
@@ -145,7 +140,14 @@ static const struct sysfs_ops blk_crypto_attr_ops = {
 
 static void blk_crypto_release(struct kobject *kobj)
 {
-	kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
+	struct blk_crypto_profile *profile =
+		container_of(kobj, struct blk_crypto_profile, kobj);
+
+	kvfree(profile->slot_hashtable);
+	kvfree_sensitive(profile->slots,
+			 sizeof(profile->slots[0]) * profile->num_slots);
+	memzero_explicit(profile, sizeof(*profile));
+	kfree(profile);
 }
 
 static struct kobj_type blk_crypto_ktype = {
@@ -160,30 +162,20 @@ static struct kobj_type blk_crypto_ktype = {
  */
 int blk_crypto_sysfs_register(struct request_queue *q)
 {
-	struct blk_crypto_kobj *obj;
 	int err;
 
 	if (!q->crypto_profile)
 		return 0;
 
-	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
-	if (!obj)
-		return -ENOMEM;
-	obj->profile = q->crypto_profile;
-
-	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
-				   "crypto");
-	if (err) {
-		kobject_put(&obj->kobj);
-		return err;
-	}
-	q->crypto_kobject = &obj->kobj;
-	return 0;
+	err = kobject_add(&q->crypto_profile->kobj, &q->kobj, "crypto");
+	if (err)
+		kobject_put(&q->crypto_profile->kobj);
+	return err;
 }
 
 void blk_crypto_sysfs_unregister(struct request_queue *q)
 {
-	kobject_put(q->crypto_kobject);
+	kobject_del(&q->crypto_profile->kobj);
 }
 
 static inline void blk_crypto_hw_enter(struct blk_crypto_profile *profile)
@@ -205,30 +197,13 @@ static inline void blk_crypto_hw_exit(struct blk_crypto_profile *profile)
 		pm_runtime_put_sync(profile->dev);
 }
 
-/**
- * blk_crypto_profile_init() - Initialize a blk_crypto_profile
- * @profile: the blk_crypto_profile to initialize
- * @num_slots: the number of keyslots
- *
- * Storage drivers must call this when starting to set up a blk_crypto_profile,
- * before filling in additional fields.
- *
- * Return: 0 on success, or else a negative error code.
- */
-int blk_crypto_profile_init(struct blk_crypto_profile *profile,
-			    unsigned int num_slots)
+/* Initialize keyslot management data. */
+static int blk_crypto_profile_init_slots(struct blk_crypto_profile *profile,
+		unsigned int num_slots)
 {
+	unsigned int slot_hashtable_size;
 	unsigned int slot;
 	unsigned int i;
-	unsigned int slot_hashtable_size;
-
-	memset(profile, 0, sizeof(*profile));
-	init_rwsem(&profile->lock);
-
-	if (num_slots == 0)
-		return 0;
-
-	/* Initialize keyslot management data. */
 
 	profile->slots = kvcalloc(num_slots, sizeof(profile->slots[0]),
 				  GFP_KERNEL);
@@ -261,48 +236,75 @@ int blk_crypto_profile_init(struct blk_crypto_profile *profile,
 		kvmalloc_array(slot_hashtable_size,
 			       sizeof(profile->slot_hashtable[0]), GFP_KERNEL);
 	if (!profile->slot_hashtable)
-		goto err_destroy;
+		return -ENOMEM;
 	for (i = 0; i < slot_hashtable_size; i++)
 		INIT_HLIST_HEAD(&profile->slot_hashtable[i]);
-
 	return 0;
+}
+
+/**
+ * blk_crypto_profile_alloc() - Allocate a blk_crypto_profile
+ * @num_slots: the number of keyslots
+ *
+ * Storage drivers must call this when starting to set up a blk_crypto_profile,
+ * before filling in additional fields.
+ *
+ * Return: pointer to the profile on success, or ele %NULL.
+ */
+struct blk_crypto_profile *blk_crypto_profile_alloc(unsigned int num_slots)
+{
+	struct blk_crypto_profile *profile;
 
-err_destroy:
-	blk_crypto_profile_destroy(profile);
-	return -ENOMEM;
+	profile = kzalloc(sizeof(*profile), GFP_KERNEL);
+	if (!profile)
+		return NULL;
+	kobject_init(&profile->kobj, &blk_crypto_ktype);
+	init_rwsem(&profile->lock);
+	if (num_slots && blk_crypto_profile_init_slots(profile, num_slots)) {
+		blk_crypto_profile_put(profile);
+		return NULL;
+	}
+
+	return profile;
 }
-EXPORT_SYMBOL_GPL(blk_crypto_profile_init);
+EXPORT_SYMBOL_GPL(blk_crypto_profile_alloc);
 
-static void blk_crypto_profile_destroy_callback(void *profile)
+void blk_crypto_profile_put(struct blk_crypto_profile *profile)
 {
-	blk_crypto_profile_destroy(profile);
+	if (profile)
+		kobject_put(&profile->kobj);
+}
+EXPORT_SYMBOL_GPL(blk_crypto_profile_put);
+
+static void blk_crypto_profile_put_callback(void *profile)
+{
+	blk_crypto_profile_put(profile);
 }
 
 /**
- * devm_blk_crypto_profile_init() - Resource-managed blk_crypto_profile_init()
+ * devm_blk_crypto_profile_alloc() - Resource-managed blk_crypto_profile_alloc()
  * @dev: the device which owns the blk_crypto_profile
- * @profile: the blk_crypto_profile to initialize
  * @num_slots: the number of keyslots
  *
- * Like blk_crypto_profile_init(), but causes blk_crypto_profile_destroy() to be
+ * Like blk_crypto_profile_alloc(), but causes blk_crypto_profile_put() to be
  * called automatically on driver detach.
  *
- * Return: 0 on success, or else a negative error code.
+ * Return: profile on success, or else %NULL.
  */
-int devm_blk_crypto_profile_init(struct device *dev,
-				 struct blk_crypto_profile *profile,
+struct blk_crypto_profile *devm_blk_crypto_profile_alloc(struct device *dev,
 				 unsigned int num_slots)
 {
-	int err = blk_crypto_profile_init(profile, num_slots);
-
-	if (err)
-		return err;
+	struct blk_crypto_profile *profile;
 
-	return devm_add_action_or_reset(dev,
-					blk_crypto_profile_destroy_callback,
-					profile);
+	profile = blk_crypto_profile_alloc(num_slots);
+	if (!profile)
+		return NULL;
+	if (devm_add_action_or_reset(dev, blk_crypto_profile_put_callback,
+			profile))
+		return NULL;
+	return profile;
 }
-EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_init);
+EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_alloc);
 
 static inline struct hlist_head *
 blk_crypto_hash_bucket_for_key(struct blk_crypto_profile *profile,
@@ -585,17 +587,6 @@ void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile)
 }
 EXPORT_SYMBOL_GPL(blk_crypto_reprogram_all_keys);
 
-void blk_crypto_profile_destroy(struct blk_crypto_profile *profile)
-{
-	if (!profile)
-		return;
-	kvfree(profile->slot_hashtable);
-	kvfree_sensitive(profile->slots,
-			 sizeof(profile->slots[0]) * profile->num_slots);
-	memzero_explicit(profile, sizeof(*profile));
-}
-EXPORT_SYMBOL_GPL(blk_crypto_profile_destroy);
-
 bool blk_crypto_register(struct blk_crypto_profile *profile,
 			 struct request_queue *q)
 {
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index e7d42f6335a2a..0d40f9e9eefbc 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1185,11 +1185,6 @@ static int dm_table_register_integrity(struct dm_table *t)
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 
-struct dm_crypto_profile {
-	struct blk_crypto_profile profile;
-	struct mapped_device *md;
-};
-
 struct dm_keyslot_evict_args {
 	const struct blk_crypto_key *key;
 	int err;
@@ -1215,8 +1210,7 @@ static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
 static int dm_keyslot_evict(struct blk_crypto_profile *profile,
 			    const struct blk_crypto_key *key, unsigned int slot)
 {
-	struct mapped_device *md =
-		container_of(profile, struct dm_crypto_profile, profile)->md;
+	struct mapped_device *md = profile->private;
 	struct dm_keyslot_evict_args args = { key };
 	struct dm_table *t;
 	int srcu_idx;
@@ -1250,15 +1244,7 @@ device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
 
 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
 {
-	struct dm_crypto_profile *dmcp = container_of(profile,
-						      struct dm_crypto_profile,
-						      profile);
-
-	if (!profile)
-		return;
-
-	blk_crypto_profile_destroy(profile);
-	kfree(dmcp);
+	blk_crypto_profile_put(profile);
 }
 
 static void dm_table_destroy_crypto_profile(struct dm_table *t)
@@ -1278,19 +1264,15 @@ static void dm_table_destroy_crypto_profile(struct dm_table *t)
  */
 static int dm_table_construct_crypto_profile(struct dm_table *t)
 {
-	struct dm_crypto_profile *dmcp;
 	struct blk_crypto_profile *profile;
 	struct dm_target *ti;
 	unsigned int i;
 	bool empty_profile = true;
 
-	dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
-	if (!dmcp)
+	profile = blk_crypto_profile_alloc(0);
+	if (!profile)
 		return -ENOMEM;
-	dmcp->md = t->md;
-
-	profile = &dmcp->profile;
-	blk_crypto_profile_init(profile, 0);
+	profile->private = t->md;
 	profile->ll_ops.keyslot_evict = dm_keyslot_evict;
 	profile->max_dun_bytes_supported = UINT_MAX;
 	memset(profile->modes_supported, 0xFF,
diff --git a/drivers/mmc/core/crypto.c b/drivers/mmc/core/crypto.c
index fec4fbf16a5b6..df3c002526cc7 100644
--- a/drivers/mmc/core/crypto.c
+++ b/drivers/mmc/core/crypto.c
@@ -16,13 +16,13 @@ void mmc_crypto_set_initial_state(struct mmc_host *host)
 {
 	/* Reset might clear all keys, so reprogram all the keys. */
 	if (host->caps2 & MMC_CAP2_CRYPTO)
-		blk_crypto_reprogram_all_keys(&host->crypto_profile);
+		blk_crypto_reprogram_all_keys(host->crypto_profile);
 }
 
 void mmc_crypto_setup_queue(struct request_queue *q, struct mmc_host *host)
 {
 	if (host->caps2 & MMC_CAP2_CRYPTO)
-		blk_crypto_register(&host->crypto_profile, q);
+		blk_crypto_register(host->crypto_profile, q);
 }
 EXPORT_SYMBOL_GPL(mmc_crypto_setup_queue);
 
diff --git a/drivers/mmc/host/cqhci-crypto.c b/drivers/mmc/host/cqhci-crypto.c
index d5f4b6972f63e..6b1c111e9e4b2 100644
--- a/drivers/mmc/host/cqhci-crypto.c
+++ b/drivers/mmc/host/cqhci-crypto.c
@@ -25,8 +25,7 @@ static const struct cqhci_crypto_alg_entry {
 static inline struct cqhci_host *
 cqhci_host_from_crypto_profile(struct blk_crypto_profile *profile)
 {
-	struct mmc_host *mmc =
-		container_of(profile, struct mmc_host, crypto_profile);
+	struct mmc_host *mmc = profile->private;
 
 	return mmc->cqe_private;
 }
@@ -169,7 +168,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 {
 	struct mmc_host *mmc = cq_host->mmc;
 	struct device *dev = mmc_dev(mmc);
-	struct blk_crypto_profile *profile = &mmc->crypto_profile;
+	struct blk_crypto_profile *profile;
 	unsigned int num_keyslots;
 	unsigned int cap_idx;
 	enum blk_crypto_mode_num blk_mode_num;
@@ -180,6 +179,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	    !(cqhci_readl(cq_host, CQHCI_CAP) & CQHCI_CAP_CS))
 		goto out;
 
+	err = -ENOMEM;
 	cq_host->crypto_capabilities.reg_val =
 			cpu_to_le32(cqhci_readl(cq_host, CQHCI_CCAP));
 
@@ -189,10 +189,8 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	cq_host->crypto_cap_array =
 		devm_kcalloc(dev, cq_host->crypto_capabilities.num_crypto_cap,
 			     sizeof(cq_host->crypto_cap_array[0]), GFP_KERNEL);
-	if (!cq_host->crypto_cap_array) {
-		err = -ENOMEM;
+	if (!cq_host->crypto_cap_array)
 		goto out;
-	}
 
 	/*
 	 * CCAP.CFGC is off by one, so the actual number of crypto
@@ -200,10 +198,10 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	 */
 	num_keyslots = cq_host->crypto_capabilities.config_count + 1;
 
-	err = devm_blk_crypto_profile_init(dev, profile, num_keyslots);
-	if (err)
+	profile = devm_blk_crypto_profile_alloc(dev, num_keyslots);
+	if (!profile)
 		goto out;
-
+	profile->private = mmc;
 	profile->ll_ops = cqhci_crypto_ops;
 	profile->dev = dev;
 
diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
index 67402baf6faee..b48ff6046bdc8 100644
--- a/drivers/scsi/ufs/ufshcd-crypto.c
+++ b/drivers/scsi/ufs/ufshcd-crypto.c
@@ -52,8 +52,7 @@ static int ufshcd_crypto_keyslot_program(struct blk_crypto_profile *profile,
 					 const struct blk_crypto_key *key,
 					 unsigned int slot)
 {
-	struct ufs_hba *hba =
-		container_of(profile, struct ufs_hba, crypto_profile);
+	struct ufs_hba *hba = profile->private;
 	const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
 	const struct ufs_crypto_alg_entry *alg =
 			&ufs_crypto_algs[key->crypto_cfg.crypto_mode];
@@ -110,10 +109,7 @@ static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
 				       const struct blk_crypto_key *key,
 				       unsigned int slot)
 {
-	struct ufs_hba *hba =
-		container_of(profile, struct ufs_hba, crypto_profile);
-
-	return ufshcd_clear_keyslot(hba, slot);
+	return ufshcd_clear_keyslot(profile->private, slot);
 }
 
 bool ufshcd_crypto_enable(struct ufs_hba *hba)
@@ -122,7 +118,7 @@ bool ufshcd_crypto_enable(struct ufs_hba *hba)
 		return false;
 
 	/* Reset might clear all keys, so reprogram all the keys. */
-	blk_crypto_reprogram_all_keys(&hba->crypto_profile);
+	blk_crypto_reprogram_all_keys(hba->crypto_profile);
 	return true;
 }
 
@@ -168,6 +164,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 	    !(hba->caps & UFSHCD_CAP_CRYPTO))
 		goto out;
 
+	err = -ENOMEM;
 	hba->crypto_capabilities.reg_val =
 			cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
 	hba->crypto_cfg_register =
@@ -175,22 +172,20 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 	hba->crypto_cap_array =
 		devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
 			     sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
-	if (!hba->crypto_cap_array) {
-		err = -ENOMEM;
+	if (!hba->crypto_cap_array)
 		goto out;
-	}
 
 	/* The actual number of configurations supported is (CFGC+1) */
-	err = devm_blk_crypto_profile_init(
-			hba->dev, &hba->crypto_profile,
+	hba->crypto_profile = devm_blk_crypto_profile_alloc(hba->dev,
 			hba->crypto_capabilities.config_count + 1);
-	if (err)
+	if (!hba->crypto_profile)
 		goto out;
 
-	hba->crypto_profile.ll_ops = ufshcd_crypto_ops;
+	hba->crypto_profile->private = hba;
+	hba->crypto_profile->ll_ops = ufshcd_crypto_ops;
 	/* UFS only supports 8 bytes for any DUN */
-	hba->crypto_profile.max_dun_bytes_supported = 8;
-	hba->crypto_profile.dev = hba->dev;
+	hba->crypto_profile->max_dun_bytes_supported = 8;
+	hba->crypto_profile->dev = hba->dev;
 
 	/*
 	 * Cache all the UFS crypto capabilities and advertise the supported
@@ -205,7 +200,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 		blk_mode_num = ufshcd_find_blk_crypto_mode(
 						hba->crypto_cap_array[cap_idx]);
 		if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
-			hba->crypto_profile.modes_supported[blk_mode_num] |=
+			hba->crypto_profile->modes_supported[blk_mode_num] |=
 				hba->crypto_cap_array[cap_idx].sdus_mask * 512;
 	}
 
@@ -236,5 +231,5 @@ void ufshcd_init_crypto(struct ufs_hba *hba)
 void ufshcd_crypto_register(struct ufs_hba *hba, struct request_queue *q)
 {
 	if (hba->caps & UFSHCD_CAP_CRYPTO)
-		blk_crypto_register(&hba->crypto_profile, q);
+		blk_crypto_register(hba->crypto_profile, q);
 }
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 94f545be183aa..94edbe3721890 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -930,7 +930,7 @@ struct ufs_hba {
 	union ufs_crypto_capabilities crypto_capabilities;
 	union ufs_crypto_cap_entry *crypto_cap_array;
 	u32 crypto_cfg_register;
-	struct blk_crypto_profile crypto_profile;
+	struct blk_crypto_profile *crypto_profile;
 #endif
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs_root;
diff --git a/include/linux/blk-crypto-profile.h b/include/linux/blk-crypto-profile.h
index bbab65bd54288..07745a4675f25 100644
--- a/include/linux/blk-crypto-profile.h
+++ b/include/linux/blk-crypto-profile.h
@@ -8,6 +8,7 @@
 
 #include <linux/bio.h>
 #include <linux/blk-crypto.h>
+#include <linux/kobject.h>
 
 struct blk_crypto_profile;
 
@@ -100,6 +101,11 @@ struct blk_crypto_profile {
 	 */
 	struct device *dev;
 
+	/**
+	 * @private: Optional private data for driver use.
+	 */
+	void *private;
+
 	/* private: The following fields shouldn't be accessed by drivers. */
 
 	/* Number of keyslots, or 0 if not applicable */
@@ -127,14 +133,13 @@ struct blk_crypto_profile {
 
 	/* Per-keyslot data */
 	struct blk_crypto_keyslot *slots;
-};
 
-int blk_crypto_profile_init(struct blk_crypto_profile *profile,
-			    unsigned int num_slots);
+	struct kobject kobj;
+};
 
-int devm_blk_crypto_profile_init(struct device *dev,
-				 struct blk_crypto_profile *profile,
-				 unsigned int num_slots);
+struct blk_crypto_profile *blk_crypto_profile_alloc(unsigned int num_slots);
+struct blk_crypto_profile *devm_blk_crypto_profile_alloc(struct device *dev,
+		unsigned int num_slots);
 
 unsigned int blk_crypto_keyslot_index(struct blk_crypto_keyslot *slot);
 
@@ -152,7 +157,7 @@ int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
 
 void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile);
 
-void blk_crypto_profile_destroy(struct blk_crypto_profile *profile);
+void blk_crypto_profile_put(struct blk_crypto_profile *profile);
 
 void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent,
 				       const struct blk_crypto_profile *child);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 34724b15813b7..390e3c4ad64b6 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -413,7 +413,6 @@ struct request_queue {
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 	struct blk_crypto_profile *crypto_profile;
-	struct kobject *crypto_kobject;
 #endif
 
 	unsigned int		rq_timeout;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 7afb57cab00b7..8d6069503c0dc 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -495,7 +495,7 @@ struct mmc_host {
 
 	/* Inline encryption support */
 #ifdef CONFIG_MMC_CRYPTO
-	struct blk_crypto_profile crypto_profile;
+	struct blk_crypto_profile *crypto_profile;
 #endif
 
 	/* Host Software Queue support */
-- 
2.30.2

--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel

[PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Christoph Hellwig]

Once the blk_crypto_profile is exposed in sysfs it needs to stay alive
as long as sysfs accesses are possibly pending.  Ensure that by removing
the blk_crypto_kobj wrapper and just embedding the kobject into the
actual blk_crypto_profile.  This requires the blk_crypto_profile
structure to be dynamically allocated, which in turn requires a private
data pointer for driver use.

Fixes: 20f01f163203 ("blk-crypto: show crypto capabilities in sysfs")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 Documentation/block/inline-encryption.rst |  10 +-
 block/blk-crypto-fallback.c               |  20 +--
 block/blk-crypto-profile.c                | 143 ++++++++++------------
 drivers/md/dm-table.c                     |  28 +----
 drivers/mmc/core/crypto.c                 |   4 +-
 drivers/mmc/host/cqhci-crypto.c           |  16 ++-
 drivers/scsi/ufs/ufshcd-crypto.c          |  31 ++---
 drivers/scsi/ufs/ufshcd.h                 |   2 +-
 include/linux/blk-crypto-profile.h        |  19 +--
 include/linux/blkdev.h                    |   1 -
 include/linux/mmc/host.h                  |   2 +-
 11 files changed, 123 insertions(+), 153 deletions(-)

diff --git a/Documentation/block/inline-encryption.rst b/Documentation/block/inline-encryption.rst
index 4d151fbe20583..0d740b0f9faf3 100644
--- a/Documentation/block/inline-encryption.rst
+++ b/Documentation/block/inline-encryption.rst
@@ -230,8 +230,8 @@ API presented to device drivers
 
 A device driver that wants to support inline encryption must set up a
 blk_crypto_profile in the request_queue of its device.  To do this, it first
-must call ``blk_crypto_profile_init()`` (or its resource-managed variant
-``devm_blk_crypto_profile_init()``), providing the number of keyslots.
+must call ``blk_crypto_profile_alloc()`` (or its resource-managed variant
+``devm_blk_crypto_profile_alloc()``), providing the number of keyslots.
 
 Next, it must advertise its crypto capabilities by setting fields in the
 blk_crypto_profile, e.g. ``modes_supported`` and ``max_dun_bytes_supported``.
@@ -259,9 +259,9 @@ If there are situations where the inline encryption hardware loses the contents
 of its keyslots, e.g. device resets, the driver must handle reprogramming the
 keyslots.  To do this, the driver may call ``blk_crypto_reprogram_all_keys()``.
 
-Finally, if the driver used ``blk_crypto_profile_init()`` instead of
-``devm_blk_crypto_profile_init()``, then it is responsible for calling
-``blk_crypto_profile_destroy()`` when the crypto profile is no longer needed.
+Finally, if the driver used ``blk_crypto_profile_alloc()`` instead of
+``devm_blk_crypto_profile_alloc()``, then it is responsible for calling
+``blk_crypto_profile_put()`` when the crypto profile is no longer needed.
 
 Layered Devices
 ===============
diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
index 5d1aa5b1d30a1..729974028e448 100644
--- a/block/blk-crypto-fallback.c
+++ b/block/blk-crypto-fallback.c
@@ -78,7 +78,7 @@ static struct blk_crypto_fallback_keyslot {
 	struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
 } *blk_crypto_keyslots;
 
-static struct blk_crypto_profile blk_crypto_fallback_profile;
+static struct blk_crypto_profile *blk_crypto_fallback_profile;
 static struct workqueue_struct *blk_crypto_wq;
 static mempool_t *blk_crypto_bounce_page_pool;
 static struct bio_set crypto_bio_split;
@@ -293,7 +293,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
 	 * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
 	 * this bio's algorithm and key.
 	 */
-	blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
+	blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
 					bc->bc_key, &slot);
 	if (blk_st != BLK_STS_OK) {
 		src_bio->bi_status = blk_st;
@@ -396,7 +396,7 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
 	 * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
 	 * this bio's algorithm and key.
 	 */
-	blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
+	blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
 					bc->bc_key, &slot);
 	if (blk_st != BLK_STS_OK) {
 		bio->bi_status = blk_st;
@@ -500,7 +500,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
 		return false;
 	}
 
-	if (!__blk_crypto_cfg_supported(&blk_crypto_fallback_profile,
+	if (!__blk_crypto_cfg_supported(blk_crypto_fallback_profile,
 					&bc->bc_key->crypto_cfg)) {
 		bio->bi_status = BLK_STS_NOTSUPP;
 		return false;
@@ -527,7 +527,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
 
 int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
 {
-	return __blk_crypto_evict_key(&blk_crypto_fallback_profile, key);
+	return __blk_crypto_evict_key(blk_crypto_fallback_profile, key);
 }
 
 static bool blk_crypto_fallback_inited;
@@ -535,7 +535,7 @@ static int blk_crypto_fallback_init(void)
 {
 	int i;
 	int err;
-	struct blk_crypto_profile *profile = &blk_crypto_fallback_profile;
+	struct blk_crypto_profile *profile;
 
 	if (blk_crypto_fallback_inited)
 		return 0;
@@ -546,10 +546,10 @@ static int blk_crypto_fallback_init(void)
 	if (err)
 		goto out;
 
-	err = blk_crypto_profile_init(profile, blk_crypto_num_keyslots);
-	if (err)
-		goto fail_free_bioset;
 	err = -ENOMEM;
+	profile = blk_crypto_profile_alloc(blk_crypto_num_keyslots);
+	if (!profile)
+		goto fail_free_bioset;
 
 	profile->ll_ops = blk_crypto_fallback_ll_ops;
 	profile->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
@@ -598,7 +598,7 @@ static int blk_crypto_fallback_init(void)
 fail_free_wq:
 	destroy_workqueue(blk_crypto_wq);
 fail_destroy_profile:
-	blk_crypto_profile_destroy(profile);
+	blk_crypto_profile_put(profile);
 fail_free_bioset:
 	bioset_exit(&crypto_bio_split);
 out:
diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c
index 4f444323cb491..e4e14322d2f2e 100644
--- a/block/blk-crypto-profile.c
+++ b/block/blk-crypto-profile.c
@@ -42,11 +42,6 @@ struct blk_crypto_keyslot {
 	struct blk_crypto_profile *profile;
 };
 
-struct blk_crypto_kobj {
-	struct kobject kobj;
-	struct blk_crypto_profile *profile;
-};
-
 struct blk_crypto_attr {
 	struct attribute attr;
 	ssize_t (*show)(struct blk_crypto_profile *profile,
@@ -55,7 +50,7 @@ struct blk_crypto_attr {
 
 static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
 {
-	return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
+	return container_of(kobj, struct blk_crypto_profile, kobj);
 }
 
 static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
@@ -145,7 +140,14 @@ static const struct sysfs_ops blk_crypto_attr_ops = {
 
 static void blk_crypto_release(struct kobject *kobj)
 {
-	kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
+	struct blk_crypto_profile *profile =
+		container_of(kobj, struct blk_crypto_profile, kobj);
+
+	kvfree(profile->slot_hashtable);
+	kvfree_sensitive(profile->slots,
+			 sizeof(profile->slots[0]) * profile->num_slots);
+	memzero_explicit(profile, sizeof(*profile));
+	kfree(profile);
 }
 
 static struct kobj_type blk_crypto_ktype = {
@@ -160,30 +162,20 @@ static struct kobj_type blk_crypto_ktype = {
  */
 int blk_crypto_sysfs_register(struct request_queue *q)
 {
-	struct blk_crypto_kobj *obj;
 	int err;
 
 	if (!q->crypto_profile)
 		return 0;
 
-	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
-	if (!obj)
-		return -ENOMEM;
-	obj->profile = q->crypto_profile;
-
-	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
-				   "crypto");
-	if (err) {
-		kobject_put(&obj->kobj);
-		return err;
-	}
-	q->crypto_kobject = &obj->kobj;
-	return 0;
+	err = kobject_add(&q->crypto_profile->kobj, &q->kobj, "crypto");
+	if (err)
+		kobject_put(&q->crypto_profile->kobj);
+	return err;
 }
 
 void blk_crypto_sysfs_unregister(struct request_queue *q)
 {
-	kobject_put(q->crypto_kobject);
+	kobject_del(&q->crypto_profile->kobj);
 }
 
 static inline void blk_crypto_hw_enter(struct blk_crypto_profile *profile)
@@ -205,30 +197,13 @@ static inline void blk_crypto_hw_exit(struct blk_crypto_profile *profile)
 		pm_runtime_put_sync(profile->dev);
 }
 
-/**
- * blk_crypto_profile_init() - Initialize a blk_crypto_profile
- * @profile: the blk_crypto_profile to initialize
- * @num_slots: the number of keyslots
- *
- * Storage drivers must call this when starting to set up a blk_crypto_profile,
- * before filling in additional fields.
- *
- * Return: 0 on success, or else a negative error code.
- */
-int blk_crypto_profile_init(struct blk_crypto_profile *profile,
-			    unsigned int num_slots)
+/* Initialize keyslot management data. */
+static int blk_crypto_profile_init_slots(struct blk_crypto_profile *profile,
+		unsigned int num_slots)
 {
+	unsigned int slot_hashtable_size;
 	unsigned int slot;
 	unsigned int i;
-	unsigned int slot_hashtable_size;
-
-	memset(profile, 0, sizeof(*profile));
-	init_rwsem(&profile->lock);
-
-	if (num_slots == 0)
-		return 0;
-
-	/* Initialize keyslot management data. */
 
 	profile->slots = kvcalloc(num_slots, sizeof(profile->slots[0]),
 				  GFP_KERNEL);
@@ -261,48 +236,75 @@ int blk_crypto_profile_init(struct blk_crypto_profile *profile,
 		kvmalloc_array(slot_hashtable_size,
 			       sizeof(profile->slot_hashtable[0]), GFP_KERNEL);
 	if (!profile->slot_hashtable)
-		goto err_destroy;
+		return -ENOMEM;
 	for (i = 0; i < slot_hashtable_size; i++)
 		INIT_HLIST_HEAD(&profile->slot_hashtable[i]);
-
 	return 0;
+}
+
+/**
+ * blk_crypto_profile_alloc() - Allocate a blk_crypto_profile
+ * @num_slots: the number of keyslots
+ *
+ * Storage drivers must call this when starting to set up a blk_crypto_profile,
+ * before filling in additional fields.
+ *
+ * Return: pointer to the profile on success, or ele %NULL.
+ */
+struct blk_crypto_profile *blk_crypto_profile_alloc(unsigned int num_slots)
+{
+	struct blk_crypto_profile *profile;
 
-err_destroy:
-	blk_crypto_profile_destroy(profile);
-	return -ENOMEM;
+	profile = kzalloc(sizeof(*profile), GFP_KERNEL);
+	if (!profile)
+		return NULL;
+	kobject_init(&profile->kobj, &blk_crypto_ktype);
+	init_rwsem(&profile->lock);
+	if (num_slots && blk_crypto_profile_init_slots(profile, num_slots)) {
+		blk_crypto_profile_put(profile);
+		return NULL;
+	}
+
+	return profile;
 }
-EXPORT_SYMBOL_GPL(blk_crypto_profile_init);
+EXPORT_SYMBOL_GPL(blk_crypto_profile_alloc);
 
-static void blk_crypto_profile_destroy_callback(void *profile)
+void blk_crypto_profile_put(struct blk_crypto_profile *profile)
 {
-	blk_crypto_profile_destroy(profile);
+	if (profile)
+		kobject_put(&profile->kobj);
+}
+EXPORT_SYMBOL_GPL(blk_crypto_profile_put);
+
+static void blk_crypto_profile_put_callback(void *profile)
+{
+	blk_crypto_profile_put(profile);
 }
 
 /**
- * devm_blk_crypto_profile_init() - Resource-managed blk_crypto_profile_init()
+ * devm_blk_crypto_profile_alloc() - Resource-managed blk_crypto_profile_alloc()
  * @dev: the device which owns the blk_crypto_profile
- * @profile: the blk_crypto_profile to initialize
  * @num_slots: the number of keyslots
  *
- * Like blk_crypto_profile_init(), but causes blk_crypto_profile_destroy() to be
+ * Like blk_crypto_profile_alloc(), but causes blk_crypto_profile_put() to be
  * called automatically on driver detach.
  *
- * Return: 0 on success, or else a negative error code.
+ * Return: profile on success, or else %NULL.
  */
-int devm_blk_crypto_profile_init(struct device *dev,
-				 struct blk_crypto_profile *profile,
+struct blk_crypto_profile *devm_blk_crypto_profile_alloc(struct device *dev,
 				 unsigned int num_slots)
 {
-	int err = blk_crypto_profile_init(profile, num_slots);
-
-	if (err)
-		return err;
+	struct blk_crypto_profile *profile;
 
-	return devm_add_action_or_reset(dev,
-					blk_crypto_profile_destroy_callback,
-					profile);
+	profile = blk_crypto_profile_alloc(num_slots);
+	if (!profile)
+		return NULL;
+	if (devm_add_action_or_reset(dev, blk_crypto_profile_put_callback,
+			profile))
+		return NULL;
+	return profile;
 }
-EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_init);
+EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_alloc);
 
 static inline struct hlist_head *
 blk_crypto_hash_bucket_for_key(struct blk_crypto_profile *profile,
@@ -585,17 +587,6 @@ void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile)
 }
 EXPORT_SYMBOL_GPL(blk_crypto_reprogram_all_keys);
 
-void blk_crypto_profile_destroy(struct blk_crypto_profile *profile)
-{
-	if (!profile)
-		return;
-	kvfree(profile->slot_hashtable);
-	kvfree_sensitive(profile->slots,
-			 sizeof(profile->slots[0]) * profile->num_slots);
-	memzero_explicit(profile, sizeof(*profile));
-}
-EXPORT_SYMBOL_GPL(blk_crypto_profile_destroy);
-
 bool blk_crypto_register(struct blk_crypto_profile *profile,
 			 struct request_queue *q)
 {
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index e7d42f6335a2a..0d40f9e9eefbc 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1185,11 +1185,6 @@ static int dm_table_register_integrity(struct dm_table *t)
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 
-struct dm_crypto_profile {
-	struct blk_crypto_profile profile;
-	struct mapped_device *md;
-};
-
 struct dm_keyslot_evict_args {
 	const struct blk_crypto_key *key;
 	int err;
@@ -1215,8 +1210,7 @@ static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
 static int dm_keyslot_evict(struct blk_crypto_profile *profile,
 			    const struct blk_crypto_key *key, unsigned int slot)
 {
-	struct mapped_device *md =
-		container_of(profile, struct dm_crypto_profile, profile)->md;
+	struct mapped_device *md = profile->private;
 	struct dm_keyslot_evict_args args = { key };
 	struct dm_table *t;
 	int srcu_idx;
@@ -1250,15 +1244,7 @@ device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
 
 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
 {
-	struct dm_crypto_profile *dmcp = container_of(profile,
-						      struct dm_crypto_profile,
-						      profile);
-
-	if (!profile)
-		return;
-
-	blk_crypto_profile_destroy(profile);
-	kfree(dmcp);
+	blk_crypto_profile_put(profile);
 }
 
 static void dm_table_destroy_crypto_profile(struct dm_table *t)
@@ -1278,19 +1264,15 @@ static void dm_table_destroy_crypto_profile(struct dm_table *t)
  */
 static int dm_table_construct_crypto_profile(struct dm_table *t)
 {
-	struct dm_crypto_profile *dmcp;
 	struct blk_crypto_profile *profile;
 	struct dm_target *ti;
 	unsigned int i;
 	bool empty_profile = true;
 
-	dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
-	if (!dmcp)
+	profile = blk_crypto_profile_alloc(0);
+	if (!profile)
 		return -ENOMEM;
-	dmcp->md = t->md;
-
-	profile = &dmcp->profile;
-	blk_crypto_profile_init(profile, 0);
+	profile->private = t->md;
 	profile->ll_ops.keyslot_evict = dm_keyslot_evict;
 	profile->max_dun_bytes_supported = UINT_MAX;
 	memset(profile->modes_supported, 0xFF,
diff --git a/drivers/mmc/core/crypto.c b/drivers/mmc/core/crypto.c
index fec4fbf16a5b6..df3c002526cc7 100644
--- a/drivers/mmc/core/crypto.c
+++ b/drivers/mmc/core/crypto.c
@@ -16,13 +16,13 @@ void mmc_crypto_set_initial_state(struct mmc_host *host)
 {
 	/* Reset might clear all keys, so reprogram all the keys. */
 	if (host->caps2 & MMC_CAP2_CRYPTO)
-		blk_crypto_reprogram_all_keys(&host->crypto_profile);
+		blk_crypto_reprogram_all_keys(host->crypto_profile);
 }
 
 void mmc_crypto_setup_queue(struct request_queue *q, struct mmc_host *host)
 {
 	if (host->caps2 & MMC_CAP2_CRYPTO)
-		blk_crypto_register(&host->crypto_profile, q);
+		blk_crypto_register(host->crypto_profile, q);
 }
 EXPORT_SYMBOL_GPL(mmc_crypto_setup_queue);
 
diff --git a/drivers/mmc/host/cqhci-crypto.c b/drivers/mmc/host/cqhci-crypto.c
index d5f4b6972f63e..6b1c111e9e4b2 100644
--- a/drivers/mmc/host/cqhci-crypto.c
+++ b/drivers/mmc/host/cqhci-crypto.c
@@ -25,8 +25,7 @@ static const struct cqhci_crypto_alg_entry {
 static inline struct cqhci_host *
 cqhci_host_from_crypto_profile(struct blk_crypto_profile *profile)
 {
-	struct mmc_host *mmc =
-		container_of(profile, struct mmc_host, crypto_profile);
+	struct mmc_host *mmc = profile->private;
 
 	return mmc->cqe_private;
 }
@@ -169,7 +168,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 {
 	struct mmc_host *mmc = cq_host->mmc;
 	struct device *dev = mmc_dev(mmc);
-	struct blk_crypto_profile *profile = &mmc->crypto_profile;
+	struct blk_crypto_profile *profile;
 	unsigned int num_keyslots;
 	unsigned int cap_idx;
 	enum blk_crypto_mode_num blk_mode_num;
@@ -180,6 +179,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	    !(cqhci_readl(cq_host, CQHCI_CAP) & CQHCI_CAP_CS))
 		goto out;
 
+	err = -ENOMEM;
 	cq_host->crypto_capabilities.reg_val =
 			cpu_to_le32(cqhci_readl(cq_host, CQHCI_CCAP));
 
@@ -189,10 +189,8 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	cq_host->crypto_cap_array =
 		devm_kcalloc(dev, cq_host->crypto_capabilities.num_crypto_cap,
 			     sizeof(cq_host->crypto_cap_array[0]), GFP_KERNEL);
-	if (!cq_host->crypto_cap_array) {
-		err = -ENOMEM;
+	if (!cq_host->crypto_cap_array)
 		goto out;
-	}
 
 	/*
 	 * CCAP.CFGC is off by one, so the actual number of crypto
@@ -200,10 +198,10 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	 */
 	num_keyslots = cq_host->crypto_capabilities.config_count + 1;
 
-	err = devm_blk_crypto_profile_init(dev, profile, num_keyslots);
-	if (err)
+	profile = devm_blk_crypto_profile_alloc(dev, num_keyslots);
+	if (!profile)
 		goto out;
-
+	profile->private = mmc;
 	profile->ll_ops = cqhci_crypto_ops;
 	profile->dev = dev;
 
diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
index 67402baf6faee..b48ff6046bdc8 100644
--- a/drivers/scsi/ufs/ufshcd-crypto.c
+++ b/drivers/scsi/ufs/ufshcd-crypto.c
@@ -52,8 +52,7 @@ static int ufshcd_crypto_keyslot_program(struct blk_crypto_profile *profile,
 					 const struct blk_crypto_key *key,
 					 unsigned int slot)
 {
-	struct ufs_hba *hba =
-		container_of(profile, struct ufs_hba, crypto_profile);
+	struct ufs_hba *hba = profile->private;
 	const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
 	const struct ufs_crypto_alg_entry *alg =
 			&ufs_crypto_algs[key->crypto_cfg.crypto_mode];
@@ -110,10 +109,7 @@ static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
 				       const struct blk_crypto_key *key,
 				       unsigned int slot)
 {
-	struct ufs_hba *hba =
-		container_of(profile, struct ufs_hba, crypto_profile);
-
-	return ufshcd_clear_keyslot(hba, slot);
+	return ufshcd_clear_keyslot(profile->private, slot);
 }
 
 bool ufshcd_crypto_enable(struct ufs_hba *hba)
@@ -122,7 +118,7 @@ bool ufshcd_crypto_enable(struct ufs_hba *hba)
 		return false;
 
 	/* Reset might clear all keys, so reprogram all the keys. */
-	blk_crypto_reprogram_all_keys(&hba->crypto_profile);
+	blk_crypto_reprogram_all_keys(hba->crypto_profile);
 	return true;
 }
 
@@ -168,6 +164,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 	    !(hba->caps & UFSHCD_CAP_CRYPTO))
 		goto out;
 
+	err = -ENOMEM;
 	hba->crypto_capabilities.reg_val =
 			cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
 	hba->crypto_cfg_register =
@@ -175,22 +172,20 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 	hba->crypto_cap_array =
 		devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
 			     sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
-	if (!hba->crypto_cap_array) {
-		err = -ENOMEM;
+	if (!hba->crypto_cap_array)
 		goto out;
-	}
 
 	/* The actual number of configurations supported is (CFGC+1) */
-	err = devm_blk_crypto_profile_init(
-			hba->dev, &hba->crypto_profile,
+	hba->crypto_profile = devm_blk_crypto_profile_alloc(hba->dev,
 			hba->crypto_capabilities.config_count + 1);
-	if (err)
+	if (!hba->crypto_profile)
 		goto out;
 
-	hba->crypto_profile.ll_ops = ufshcd_crypto_ops;
+	hba->crypto_profile->private = hba;
+	hba->crypto_profile->ll_ops = ufshcd_crypto_ops;
 	/* UFS only supports 8 bytes for any DUN */
-	hba->crypto_profile.max_dun_bytes_supported = 8;
-	hba->crypto_profile.dev = hba->dev;
+	hba->crypto_profile->max_dun_bytes_supported = 8;
+	hba->crypto_profile->dev = hba->dev;
 
 	/*
 	 * Cache all the UFS crypto capabilities and advertise the supported
@@ -205,7 +200,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 		blk_mode_num = ufshcd_find_blk_crypto_mode(
 						hba->crypto_cap_array[cap_idx]);
 		if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
-			hba->crypto_profile.modes_supported[blk_mode_num] |=
+			hba->crypto_profile->modes_supported[blk_mode_num] |=
 				hba->crypto_cap_array[cap_idx].sdus_mask * 512;
 	}
 
@@ -236,5 +231,5 @@ void ufshcd_init_crypto(struct ufs_hba *hba)
 void ufshcd_crypto_register(struct ufs_hba *hba, struct request_queue *q)
 {
 	if (hba->caps & UFSHCD_CAP_CRYPTO)
-		blk_crypto_register(&hba->crypto_profile, q);
+		blk_crypto_register(hba->crypto_profile, q);
 }
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 94f545be183aa..94edbe3721890 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -930,7 +930,7 @@ struct ufs_hba {
 	union ufs_crypto_capabilities crypto_capabilities;
 	union ufs_crypto_cap_entry *crypto_cap_array;
 	u32 crypto_cfg_register;
-	struct blk_crypto_profile crypto_profile;
+	struct blk_crypto_profile *crypto_profile;
 #endif
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs_root;
diff --git a/include/linux/blk-crypto-profile.h b/include/linux/blk-crypto-profile.h
index bbab65bd54288..07745a4675f25 100644
--- a/include/linux/blk-crypto-profile.h
+++ b/include/linux/blk-crypto-profile.h
@@ -8,6 +8,7 @@
 
 #include <linux/bio.h>
 #include <linux/blk-crypto.h>
+#include <linux/kobject.h>
 
 struct blk_crypto_profile;
 
@@ -100,6 +101,11 @@ struct blk_crypto_profile {
 	 */
 	struct device *dev;
 
+	/**
+	 * @private: Optional private data for driver use.
+	 */
+	void *private;
+
 	/* private: The following fields shouldn't be accessed by drivers. */
 
 	/* Number of keyslots, or 0 if not applicable */
@@ -127,14 +133,13 @@ struct blk_crypto_profile {
 
 	/* Per-keyslot data */
 	struct blk_crypto_keyslot *slots;
-};
 
-int blk_crypto_profile_init(struct blk_crypto_profile *profile,
-			    unsigned int num_slots);
+	struct kobject kobj;
+};
 
-int devm_blk_crypto_profile_init(struct device *dev,
-				 struct blk_crypto_profile *profile,
-				 unsigned int num_slots);
+struct blk_crypto_profile *blk_crypto_profile_alloc(unsigned int num_slots);
+struct blk_crypto_profile *devm_blk_crypto_profile_alloc(struct device *dev,
+		unsigned int num_slots);
 
 unsigned int blk_crypto_keyslot_index(struct blk_crypto_keyslot *slot);
 
@@ -152,7 +157,7 @@ int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
 
 void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile);
 
-void blk_crypto_profile_destroy(struct blk_crypto_profile *profile);
+void blk_crypto_profile_put(struct blk_crypto_profile *profile);
 
 void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent,
 				       const struct blk_crypto_profile *child);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 34724b15813b7..390e3c4ad64b6 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -413,7 +413,6 @@ struct request_queue {
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 	struct blk_crypto_profile *crypto_profile;
-	struct kobject *crypto_kobject;
 #endif
 
 	unsigned int		rq_timeout;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 7afb57cab00b7..8d6069503c0dc 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -495,7 +495,7 @@ struct mmc_host {
 
 	/* Inline encryption support */
 #ifdef CONFIG_MMC_CRYPTO
-	struct blk_crypto_profile crypto_profile;
+	struct blk_crypto_profile *crypto_profile;
 #endif
 
 	/* Host Software Queue support */
-- 
2.30.2

Re: [dm-devel] [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Ulf Hansson]

On Wed, 20 Apr 2022 at 08:48, Christoph Hellwig <hch@lst.de> wrote:
>
> Once the blk_crypto_profile is exposed in sysfs it needs to stay alive
> as long as sysfs accesses are possibly pending.  Ensure that by removing
> the blk_crypto_kobj wrapper and just embedding the kobject into the
> actual blk_crypto_profile.  This requires the blk_crypto_profile
> structure to be dynamically allocated, which in turn requires a private
> data pointer for driver use.
>
> Fixes: 20f01f163203 ("blk-crypto: show crypto capabilities in sysfs")
> Signed-off-by: Christoph Hellwig <hch@lst.de>

I am not surprised that you seem to have found lifecycle issues, as
it's a rather complex path of how to deal with the resources
correctly. Just for mmc internally, we have three layers of code that
gets involved.

That said, I think the code in the $subject patch looks good to me,
but I have to admit that it's not a full in-depth review - and I
haven't done any tests.

Nevertheless, feel free to add:
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  Documentation/block/inline-encryption.rst |  10 +-
>  block/blk-crypto-fallback.c               |  20 +--
>  block/blk-crypto-profile.c                | 143 ++++++++++------------
>  drivers/md/dm-table.c                     |  28 +----
>  drivers/mmc/core/crypto.c                 |   4 +-
>  drivers/mmc/host/cqhci-crypto.c           |  16 ++-
>  drivers/scsi/ufs/ufshcd-crypto.c          |  31 ++---
>  drivers/scsi/ufs/ufshcd.h                 |   2 +-
>  include/linux/blk-crypto-profile.h        |  19 +--
>  include/linux/blkdev.h                    |   1 -
>  include/linux/mmc/host.h                  |   2 +-
>  11 files changed, 123 insertions(+), 153 deletions(-)
>
> diff --git a/Documentation/block/inline-encryption.rst b/Documentation/block/inline-encryption.rst
> index 4d151fbe20583..0d740b0f9faf3 100644
> --- a/Documentation/block/inline-encryption.rst
> +++ b/Documentation/block/inline-encryption.rst
> @@ -230,8 +230,8 @@ API presented to device drivers
>
>  A device driver that wants to support inline encryption must set up a
>  blk_crypto_profile in the request_queue of its device.  To do this, it first
> -must call ``blk_crypto_profile_init()`` (or its resource-managed variant
> -``devm_blk_crypto_profile_init()``), providing the number of keyslots.
> +must call ``blk_crypto_profile_alloc()`` (or its resource-managed variant
> +``devm_blk_crypto_profile_alloc()``), providing the number of keyslots.
>
>  Next, it must advertise its crypto capabilities by setting fields in the
>  blk_crypto_profile, e.g. ``modes_supported`` and ``max_dun_bytes_supported``.
> @@ -259,9 +259,9 @@ If there are situations where the inline encryption hardware loses the contents
>  of its keyslots, e.g. device resets, the driver must handle reprogramming the
>  keyslots.  To do this, the driver may call ``blk_crypto_reprogram_all_keys()``.
>
> -Finally, if the driver used ``blk_crypto_profile_init()`` instead of
> -``devm_blk_crypto_profile_init()``, then it is responsible for calling
> -``blk_crypto_profile_destroy()`` when the crypto profile is no longer needed.
> +Finally, if the driver used ``blk_crypto_profile_alloc()`` instead of
> +``devm_blk_crypto_profile_alloc()``, then it is responsible for calling
> +``blk_crypto_profile_put()`` when the crypto profile is no longer needed.
>
>  Layered Devices
>  ===============
> diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
> index 5d1aa5b1d30a1..729974028e448 100644
> --- a/block/blk-crypto-fallback.c
> +++ b/block/blk-crypto-fallback.c
> @@ -78,7 +78,7 @@ static struct blk_crypto_fallback_keyslot {
>         struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
>  } *blk_crypto_keyslots;
>
> -static struct blk_crypto_profile blk_crypto_fallback_profile;
> +static struct blk_crypto_profile *blk_crypto_fallback_profile;
>  static struct workqueue_struct *blk_crypto_wq;
>  static mempool_t *blk_crypto_bounce_page_pool;
>  static struct bio_set crypto_bio_split;
> @@ -293,7 +293,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
>          * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
>          * this bio's algorithm and key.
>          */
> -       blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
> +       blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
>                                         bc->bc_key, &slot);
>         if (blk_st != BLK_STS_OK) {
>                 src_bio->bi_status = blk_st;
> @@ -396,7 +396,7 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
>          * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
>          * this bio's algorithm and key.
>          */
> -       blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
> +       blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
>                                         bc->bc_key, &slot);
>         if (blk_st != BLK_STS_OK) {
>                 bio->bi_status = blk_st;
> @@ -500,7 +500,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
>                 return false;
>         }
>
> -       if (!__blk_crypto_cfg_supported(&blk_crypto_fallback_profile,
> +       if (!__blk_crypto_cfg_supported(blk_crypto_fallback_profile,
>                                         &bc->bc_key->crypto_cfg)) {
>                 bio->bi_status = BLK_STS_NOTSUPP;
>                 return false;
> @@ -527,7 +527,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
>
>  int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
>  {
> -       return __blk_crypto_evict_key(&blk_crypto_fallback_profile, key);
> +       return __blk_crypto_evict_key(blk_crypto_fallback_profile, key);
>  }
>
>  static bool blk_crypto_fallback_inited;
> @@ -535,7 +535,7 @@ static int blk_crypto_fallback_init(void)
>  {
>         int i;
>         int err;
> -       struct blk_crypto_profile *profile = &blk_crypto_fallback_profile;
> +       struct blk_crypto_profile *profile;
>
>         if (blk_crypto_fallback_inited)
>                 return 0;
> @@ -546,10 +546,10 @@ static int blk_crypto_fallback_init(void)
>         if (err)
>                 goto out;
>
> -       err = blk_crypto_profile_init(profile, blk_crypto_num_keyslots);
> -       if (err)
> -               goto fail_free_bioset;
>         err = -ENOMEM;
> +       profile = blk_crypto_profile_alloc(blk_crypto_num_keyslots);
> +       if (!profile)
> +               goto fail_free_bioset;
>
>         profile->ll_ops = blk_crypto_fallback_ll_ops;
>         profile->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
> @@ -598,7 +598,7 @@ static int blk_crypto_fallback_init(void)
>  fail_free_wq:
>         destroy_workqueue(blk_crypto_wq);
>  fail_destroy_profile:
> -       blk_crypto_profile_destroy(profile);
> +       blk_crypto_profile_put(profile);
>  fail_free_bioset:
>         bioset_exit(&crypto_bio_split);
>  out:
> diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c
> index 4f444323cb491..e4e14322d2f2e 100644
> --- a/block/blk-crypto-profile.c
> +++ b/block/blk-crypto-profile.c
> @@ -42,11 +42,6 @@ struct blk_crypto_keyslot {
>         struct blk_crypto_profile *profile;
>  };
>
> -struct blk_crypto_kobj {
> -       struct kobject kobj;
> -       struct blk_crypto_profile *profile;
> -};
> -
>  struct blk_crypto_attr {
>         struct attribute attr;
>         ssize_t (*show)(struct blk_crypto_profile *profile,
> @@ -55,7 +50,7 @@ struct blk_crypto_attr {
>
>  static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
>  {
> -       return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
> +       return container_of(kobj, struct blk_crypto_profile, kobj);
>  }
>
>  static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
> @@ -145,7 +140,14 @@ static const struct sysfs_ops blk_crypto_attr_ops = {
>
>  static void blk_crypto_release(struct kobject *kobj)
>  {
> -       kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
> +       struct blk_crypto_profile *profile =
> +               container_of(kobj, struct blk_crypto_profile, kobj);
> +
> +       kvfree(profile->slot_hashtable);
> +       kvfree_sensitive(profile->slots,
> +                        sizeof(profile->slots[0]) * profile->num_slots);
> +       memzero_explicit(profile, sizeof(*profile));
> +       kfree(profile);
>  }
>
>  static struct kobj_type blk_crypto_ktype = {
> @@ -160,30 +162,20 @@ static struct kobj_type blk_crypto_ktype = {
>   */
>  int blk_crypto_sysfs_register(struct request_queue *q)
>  {
> -       struct blk_crypto_kobj *obj;
>         int err;
>
>         if (!q->crypto_profile)
>                 return 0;
>
> -       obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> -       if (!obj)
> -               return -ENOMEM;
> -       obj->profile = q->crypto_profile;
> -
> -       err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
> -                                  "crypto");
> -       if (err) {
> -               kobject_put(&obj->kobj);
> -               return err;
> -       }
> -       q->crypto_kobject = &obj->kobj;
> -       return 0;
> +       err = kobject_add(&q->crypto_profile->kobj, &q->kobj, "crypto");
> +       if (err)
> +               kobject_put(&q->crypto_profile->kobj);
> +       return err;
>  }
>
>  void blk_crypto_sysfs_unregister(struct request_queue *q)
>  {
> -       kobject_put(q->crypto_kobject);
> +       kobject_del(&q->crypto_profile->kobj);
>  }
>
>  static inline void blk_crypto_hw_enter(struct blk_crypto_profile *profile)
> @@ -205,30 +197,13 @@ static inline void blk_crypto_hw_exit(struct blk_crypto_profile *profile)
>                 pm_runtime_put_sync(profile->dev);
>  }
>
> -/**
> - * blk_crypto_profile_init() - Initialize a blk_crypto_profile
> - * @profile: the blk_crypto_profile to initialize
> - * @num_slots: the number of keyslots
> - *
> - * Storage drivers must call this when starting to set up a blk_crypto_profile,
> - * before filling in additional fields.
> - *
> - * Return: 0 on success, or else a negative error code.
> - */
> -int blk_crypto_profile_init(struct blk_crypto_profile *profile,
> -                           unsigned int num_slots)
> +/* Initialize keyslot management data. */
> +static int blk_crypto_profile_init_slots(struct blk_crypto_profile *profile,
> +               unsigned int num_slots)
>  {
> +       unsigned int slot_hashtable_size;
>         unsigned int slot;
>         unsigned int i;
> -       unsigned int slot_hashtable_size;
> -
> -       memset(profile, 0, sizeof(*profile));
> -       init_rwsem(&profile->lock);
> -
> -       if (num_slots == 0)
> -               return 0;
> -
> -       /* Initialize keyslot management data. */
>
>         profile->slots = kvcalloc(num_slots, sizeof(profile->slots[0]),
>                                   GFP_KERNEL);
> @@ -261,48 +236,75 @@ int blk_crypto_profile_init(struct blk_crypto_profile *profile,
>                 kvmalloc_array(slot_hashtable_size,
>                                sizeof(profile->slot_hashtable[0]), GFP_KERNEL);
>         if (!profile->slot_hashtable)
> -               goto err_destroy;
> +               return -ENOMEM;
>         for (i = 0; i < slot_hashtable_size; i++)
>                 INIT_HLIST_HEAD(&profile->slot_hashtable[i]);
> -
>         return 0;
> +}
> +
> +/**
> + * blk_crypto_profile_alloc() - Allocate a blk_crypto_profile
> + * @num_slots: the number of keyslots
> + *
> + * Storage drivers must call this when starting to set up a blk_crypto_profile,
> + * before filling in additional fields.
> + *
> + * Return: pointer to the profile on success, or ele %NULL.
> + */
> +struct blk_crypto_profile *blk_crypto_profile_alloc(unsigned int num_slots)
> +{
> +       struct blk_crypto_profile *profile;
>
> -err_destroy:
> -       blk_crypto_profile_destroy(profile);
> -       return -ENOMEM;
> +       profile = kzalloc(sizeof(*profile), GFP_KERNEL);
> +       if (!profile)
> +               return NULL;
> +       kobject_init(&profile->kobj, &blk_crypto_ktype);
> +       init_rwsem(&profile->lock);
> +       if (num_slots && blk_crypto_profile_init_slots(profile, num_slots)) {
> +               blk_crypto_profile_put(profile);
> +               return NULL;
> +       }
> +
> +       return profile;
>  }
> -EXPORT_SYMBOL_GPL(blk_crypto_profile_init);
> +EXPORT_SYMBOL_GPL(blk_crypto_profile_alloc);
>
> -static void blk_crypto_profile_destroy_callback(void *profile)
> +void blk_crypto_profile_put(struct blk_crypto_profile *profile)
>  {
> -       blk_crypto_profile_destroy(profile);
> +       if (profile)
> +               kobject_put(&profile->kobj);
> +}
> +EXPORT_SYMBOL_GPL(blk_crypto_profile_put);
> +
> +static void blk_crypto_profile_put_callback(void *profile)
> +{
> +       blk_crypto_profile_put(profile);
>  }
>
>  /**
> - * devm_blk_crypto_profile_init() - Resource-managed blk_crypto_profile_init()
> + * devm_blk_crypto_profile_alloc() - Resource-managed blk_crypto_profile_alloc()
>   * @dev: the device which owns the blk_crypto_profile
> - * @profile: the blk_crypto_profile to initialize
>   * @num_slots: the number of keyslots
>   *
> - * Like blk_crypto_profile_init(), but causes blk_crypto_profile_destroy() to be
> + * Like blk_crypto_profile_alloc(), but causes blk_crypto_profile_put() to be
>   * called automatically on driver detach.
>   *
> - * Return: 0 on success, or else a negative error code.
> + * Return: profile on success, or else %NULL.
>   */
> -int devm_blk_crypto_profile_init(struct device *dev,
> -                                struct blk_crypto_profile *profile,
> +struct blk_crypto_profile *devm_blk_crypto_profile_alloc(struct device *dev,
>                                  unsigned int num_slots)
>  {
> -       int err = blk_crypto_profile_init(profile, num_slots);
> -
> -       if (err)
> -               return err;
> +       struct blk_crypto_profile *profile;
>
> -       return devm_add_action_or_reset(dev,
> -                                       blk_crypto_profile_destroy_callback,
> -                                       profile);
> +       profile = blk_crypto_profile_alloc(num_slots);
> +       if (!profile)
> +               return NULL;
> +       if (devm_add_action_or_reset(dev, blk_crypto_profile_put_callback,
> +                       profile))
> +               return NULL;
> +       return profile;
>  }
> -EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_init);
> +EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_alloc);
>
>  static inline struct hlist_head *
>  blk_crypto_hash_bucket_for_key(struct blk_crypto_profile *profile,
> @@ -585,17 +587,6 @@ void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile)
>  }
>  EXPORT_SYMBOL_GPL(blk_crypto_reprogram_all_keys);
>
> -void blk_crypto_profile_destroy(struct blk_crypto_profile *profile)
> -{
> -       if (!profile)
> -               return;
> -       kvfree(profile->slot_hashtable);
> -       kvfree_sensitive(profile->slots,
> -                        sizeof(profile->slots[0]) * profile->num_slots);
> -       memzero_explicit(profile, sizeof(*profile));
> -}
> -EXPORT_SYMBOL_GPL(blk_crypto_profile_destroy);
> -
>  bool blk_crypto_register(struct blk_crypto_profile *profile,
>                          struct request_queue *q)
>  {
> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> index e7d42f6335a2a..0d40f9e9eefbc 100644
> --- a/drivers/md/dm-table.c
> +++ b/drivers/md/dm-table.c
> @@ -1185,11 +1185,6 @@ static int dm_table_register_integrity(struct dm_table *t)
>
>  #ifdef CONFIG_BLK_INLINE_ENCRYPTION
>
> -struct dm_crypto_profile {
> -       struct blk_crypto_profile profile;
> -       struct mapped_device *md;
> -};
> -
>  struct dm_keyslot_evict_args {
>         const struct blk_crypto_key *key;
>         int err;
> @@ -1215,8 +1210,7 @@ static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
>  static int dm_keyslot_evict(struct blk_crypto_profile *profile,
>                             const struct blk_crypto_key *key, unsigned int slot)
>  {
> -       struct mapped_device *md =
> -               container_of(profile, struct dm_crypto_profile, profile)->md;
> +       struct mapped_device *md = profile->private;
>         struct dm_keyslot_evict_args args = { key };
>         struct dm_table *t;
>         int srcu_idx;
> @@ -1250,15 +1244,7 @@ device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
>
>  void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
>  {
> -       struct dm_crypto_profile *dmcp = container_of(profile,
> -                                                     struct dm_crypto_profile,
> -                                                     profile);
> -
> -       if (!profile)
> -               return;
> -
> -       blk_crypto_profile_destroy(profile);
> -       kfree(dmcp);
> +       blk_crypto_profile_put(profile);
>  }
>
>  static void dm_table_destroy_crypto_profile(struct dm_table *t)
> @@ -1278,19 +1264,15 @@ static void dm_table_destroy_crypto_profile(struct dm_table *t)
>   */
>  static int dm_table_construct_crypto_profile(struct dm_table *t)
>  {
> -       struct dm_crypto_profile *dmcp;
>         struct blk_crypto_profile *profile;
>         struct dm_target *ti;
>         unsigned int i;
>         bool empty_profile = true;
>
> -       dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
> -       if (!dmcp)
> +       profile = blk_crypto_profile_alloc(0);
> +       if (!profile)
>                 return -ENOMEM;
> -       dmcp->md = t->md;
> -
> -       profile = &dmcp->profile;
> -       blk_crypto_profile_init(profile, 0);
> +       profile->private = t->md;
>         profile->ll_ops.keyslot_evict = dm_keyslot_evict;
>         profile->max_dun_bytes_supported = UINT_MAX;
>         memset(profile->modes_supported, 0xFF,
> diff --git a/drivers/mmc/core/crypto.c b/drivers/mmc/core/crypto.c
> index fec4fbf16a5b6..df3c002526cc7 100644
> --- a/drivers/mmc/core/crypto.c
> +++ b/drivers/mmc/core/crypto.c
> @@ -16,13 +16,13 @@ void mmc_crypto_set_initial_state(struct mmc_host *host)
>  {
>         /* Reset might clear all keys, so reprogram all the keys. */
>         if (host->caps2 & MMC_CAP2_CRYPTO)
> -               blk_crypto_reprogram_all_keys(&host->crypto_profile);
> +               blk_crypto_reprogram_all_keys(host->crypto_profile);
>  }
>
>  void mmc_crypto_setup_queue(struct request_queue *q, struct mmc_host *host)
>  {
>         if (host->caps2 & MMC_CAP2_CRYPTO)
> -               blk_crypto_register(&host->crypto_profile, q);
> +               blk_crypto_register(host->crypto_profile, q);
>  }
>  EXPORT_SYMBOL_GPL(mmc_crypto_setup_queue);
>
> diff --git a/drivers/mmc/host/cqhci-crypto.c b/drivers/mmc/host/cqhci-crypto.c
> index d5f4b6972f63e..6b1c111e9e4b2 100644
> --- a/drivers/mmc/host/cqhci-crypto.c
> +++ b/drivers/mmc/host/cqhci-crypto.c
> @@ -25,8 +25,7 @@ static const struct cqhci_crypto_alg_entry {
>  static inline struct cqhci_host *
>  cqhci_host_from_crypto_profile(struct blk_crypto_profile *profile)
>  {
> -       struct mmc_host *mmc =
> -               container_of(profile, struct mmc_host, crypto_profile);
> +       struct mmc_host *mmc = profile->private;
>
>         return mmc->cqe_private;
>  }
> @@ -169,7 +168,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
>  {
>         struct mmc_host *mmc = cq_host->mmc;
>         struct device *dev = mmc_dev(mmc);
> -       struct blk_crypto_profile *profile = &mmc->crypto_profile;
> +       struct blk_crypto_profile *profile;
>         unsigned int num_keyslots;
>         unsigned int cap_idx;
>         enum blk_crypto_mode_num blk_mode_num;
> @@ -180,6 +179,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
>             !(cqhci_readl(cq_host, CQHCI_CAP) & CQHCI_CAP_CS))
>                 goto out;
>
> +       err = -ENOMEM;
>         cq_host->crypto_capabilities.reg_val =
>                         cpu_to_le32(cqhci_readl(cq_host, CQHCI_CCAP));
>
> @@ -189,10 +189,8 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
>         cq_host->crypto_cap_array =
>                 devm_kcalloc(dev, cq_host->crypto_capabilities.num_crypto_cap,
>                              sizeof(cq_host->crypto_cap_array[0]), GFP_KERNEL);
> -       if (!cq_host->crypto_cap_array) {
> -               err = -ENOMEM;
> +       if (!cq_host->crypto_cap_array)
>                 goto out;
> -       }
>
>         /*
>          * CCAP.CFGC is off by one, so the actual number of crypto
> @@ -200,10 +198,10 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
>          */
>         num_keyslots = cq_host->crypto_capabilities.config_count + 1;
>
> -       err = devm_blk_crypto_profile_init(dev, profile, num_keyslots);
> -       if (err)
> +       profile = devm_blk_crypto_profile_alloc(dev, num_keyslots);
> +       if (!profile)
>                 goto out;
> -
> +       profile->private = mmc;
>         profile->ll_ops = cqhci_crypto_ops;
>         profile->dev = dev;
>
> diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
> index 67402baf6faee..b48ff6046bdc8 100644
> --- a/drivers/scsi/ufs/ufshcd-crypto.c
> +++ b/drivers/scsi/ufs/ufshcd-crypto.c
> @@ -52,8 +52,7 @@ static int ufshcd_crypto_keyslot_program(struct blk_crypto_profile *profile,
>                                          const struct blk_crypto_key *key,
>                                          unsigned int slot)
>  {
> -       struct ufs_hba *hba =
> -               container_of(profile, struct ufs_hba, crypto_profile);
> +       struct ufs_hba *hba = profile->private;
>         const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
>         const struct ufs_crypto_alg_entry *alg =
>                         &ufs_crypto_algs[key->crypto_cfg.crypto_mode];
> @@ -110,10 +109,7 @@ static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
>                                        const struct blk_crypto_key *key,
>                                        unsigned int slot)
>  {
> -       struct ufs_hba *hba =
> -               container_of(profile, struct ufs_hba, crypto_profile);
> -
> -       return ufshcd_clear_keyslot(hba, slot);
> +       return ufshcd_clear_keyslot(profile->private, slot);
>  }
>
>  bool ufshcd_crypto_enable(struct ufs_hba *hba)
> @@ -122,7 +118,7 @@ bool ufshcd_crypto_enable(struct ufs_hba *hba)
>                 return false;
>
>         /* Reset might clear all keys, so reprogram all the keys. */
> -       blk_crypto_reprogram_all_keys(&hba->crypto_profile);
> +       blk_crypto_reprogram_all_keys(hba->crypto_profile);
>         return true;
>  }
>
> @@ -168,6 +164,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
>             !(hba->caps & UFSHCD_CAP_CRYPTO))
>                 goto out;
>
> +       err = -ENOMEM;
>         hba->crypto_capabilities.reg_val =
>                         cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
>         hba->crypto_cfg_register =
> @@ -175,22 +172,20 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
>         hba->crypto_cap_array =
>                 devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
>                              sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
> -       if (!hba->crypto_cap_array) {
> -               err = -ENOMEM;
> +       if (!hba->crypto_cap_array)
>                 goto out;
> -       }
>
>         /* The actual number of configurations supported is (CFGC+1) */
> -       err = devm_blk_crypto_profile_init(
> -                       hba->dev, &hba->crypto_profile,
> +       hba->crypto_profile = devm_blk_crypto_profile_alloc(hba->dev,
>                         hba->crypto_capabilities.config_count + 1);
> -       if (err)
> +       if (!hba->crypto_profile)
>                 goto out;
>
> -       hba->crypto_profile.ll_ops = ufshcd_crypto_ops;
> +       hba->crypto_profile->private = hba;
> +       hba->crypto_profile->ll_ops = ufshcd_crypto_ops;
>         /* UFS only supports 8 bytes for any DUN */
> -       hba->crypto_profile.max_dun_bytes_supported = 8;
> -       hba->crypto_profile.dev = hba->dev;
> +       hba->crypto_profile->max_dun_bytes_supported = 8;
> +       hba->crypto_profile->dev = hba->dev;
>
>         /*
>          * Cache all the UFS crypto capabilities and advertise the supported
> @@ -205,7 +200,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
>                 blk_mode_num = ufshcd_find_blk_crypto_mode(
>                                                 hba->crypto_cap_array[cap_idx]);
>                 if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
> -                       hba->crypto_profile.modes_supported[blk_mode_num] |=
> +                       hba->crypto_profile->modes_supported[blk_mode_num] |=
>                                 hba->crypto_cap_array[cap_idx].sdus_mask * 512;
>         }
>
> @@ -236,5 +231,5 @@ void ufshcd_init_crypto(struct ufs_hba *hba)
>  void ufshcd_crypto_register(struct ufs_hba *hba, struct request_queue *q)
>  {
>         if (hba->caps & UFSHCD_CAP_CRYPTO)
> -               blk_crypto_register(&hba->crypto_profile, q);
> +               blk_crypto_register(hba->crypto_profile, q);
>  }
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 94f545be183aa..94edbe3721890 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -930,7 +930,7 @@ struct ufs_hba {
>         union ufs_crypto_capabilities crypto_capabilities;
>         union ufs_crypto_cap_entry *crypto_cap_array;
>         u32 crypto_cfg_register;
> -       struct blk_crypto_profile crypto_profile;
> +       struct blk_crypto_profile *crypto_profile;
>  #endif
>  #ifdef CONFIG_DEBUG_FS
>         struct dentry *debugfs_root;
> diff --git a/include/linux/blk-crypto-profile.h b/include/linux/blk-crypto-profile.h
> index bbab65bd54288..07745a4675f25 100644
> --- a/include/linux/blk-crypto-profile.h
> +++ b/include/linux/blk-crypto-profile.h
> @@ -8,6 +8,7 @@
>
>  #include <linux/bio.h>
>  #include <linux/blk-crypto.h>
> +#include <linux/kobject.h>
>
>  struct blk_crypto_profile;
>
> @@ -100,6 +101,11 @@ struct blk_crypto_profile {
>          */
>         struct device *dev;
>
> +       /**
> +        * @private: Optional private data for driver use.
> +        */
> +       void *private;
> +
>         /* private: The following fields shouldn't be accessed by drivers. */
>
>         /* Number of keyslots, or 0 if not applicable */
> @@ -127,14 +133,13 @@ struct blk_crypto_profile {
>
>         /* Per-keyslot data */
>         struct blk_crypto_keyslot *slots;
> -};
>
> -int blk_crypto_profile_init(struct blk_crypto_profile *profile,
> -                           unsigned int num_slots);
> +       struct kobject kobj;
> +};
>
> -int devm_blk_crypto_profile_init(struct device *dev,
> -                                struct blk_crypto_profile *profile,
> -                                unsigned int num_slots);
> +struct blk_crypto_profile *blk_crypto_profile_alloc(unsigned int num_slots);
> +struct blk_crypto_profile *devm_blk_crypto_profile_alloc(struct device *dev,
> +               unsigned int num_slots);
>
>  unsigned int blk_crypto_keyslot_index(struct blk_crypto_keyslot *slot);
>
> @@ -152,7 +157,7 @@ int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
>
>  void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile);
>
> -void blk_crypto_profile_destroy(struct blk_crypto_profile *profile);
> +void blk_crypto_profile_put(struct blk_crypto_profile *profile);
>
>  void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent,
>                                        const struct blk_crypto_profile *child);
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 34724b15813b7..390e3c4ad64b6 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -413,7 +413,6 @@ struct request_queue {
>
>  #ifdef CONFIG_BLK_INLINE_ENCRYPTION
>         struct blk_crypto_profile *crypto_profile;
> -       struct kobject *crypto_kobject;
>  #endif
>
>         unsigned int            rq_timeout;
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 7afb57cab00b7..8d6069503c0dc 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -495,7 +495,7 @@ struct mmc_host {
>
>         /* Inline encryption support */
>  #ifdef CONFIG_MMC_CRYPTO
> -       struct blk_crypto_profile crypto_profile;
> +       struct blk_crypto_profile *crypto_profile;
>  #endif
>
>         /* Host Software Queue support */
> --
> 2.30.2
>

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Re: [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Ulf Hansson]

On Wed, 20 Apr 2022 at 08:48, Christoph Hellwig <hch@lst.de> wrote:
>
> Once the blk_crypto_profile is exposed in sysfs it needs to stay alive
> as long as sysfs accesses are possibly pending.  Ensure that by removing
> the blk_crypto_kobj wrapper and just embedding the kobject into the
> actual blk_crypto_profile.  This requires the blk_crypto_profile
> structure to be dynamically allocated, which in turn requires a private
> data pointer for driver use.
>
> Fixes: 20f01f163203 ("blk-crypto: show crypto capabilities in sysfs")
> Signed-off-by: Christoph Hellwig <hch@lst.de>

I am not surprised that you seem to have found lifecycle issues, as
it's a rather complex path of how to deal with the resources
correctly. Just for mmc internally, we have three layers of code that
gets involved.

That said, I think the code in the $subject patch looks good to me,
but I have to admit that it's not a full in-depth review - and I
haven't done any tests.

Nevertheless, feel free to add:
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  Documentation/block/inline-encryption.rst |  10 +-
>  block/blk-crypto-fallback.c               |  20 +--
>  block/blk-crypto-profile.c                | 143 ++++++++++------------
>  drivers/md/dm-table.c                     |  28 +----
>  drivers/mmc/core/crypto.c                 |   4 +-
>  drivers/mmc/host/cqhci-crypto.c           |  16 ++-
>  drivers/scsi/ufs/ufshcd-crypto.c          |  31 ++---
>  drivers/scsi/ufs/ufshcd.h                 |   2 +-
>  include/linux/blk-crypto-profile.h        |  19 +--
>  include/linux/blkdev.h                    |   1 -
>  include/linux/mmc/host.h                  |   2 +-
>  11 files changed, 123 insertions(+), 153 deletions(-)
>
> diff --git a/Documentation/block/inline-encryption.rst b/Documentation/block/inline-encryption.rst
> index 4d151fbe20583..0d740b0f9faf3 100644
> --- a/Documentation/block/inline-encryption.rst
> +++ b/Documentation/block/inline-encryption.rst
> @@ -230,8 +230,8 @@ API presented to device drivers
>
>  A device driver that wants to support inline encryption must set up a
>  blk_crypto_profile in the request_queue of its device.  To do this, it first
> -must call ``blk_crypto_profile_init()`` (or its resource-managed variant
> -``devm_blk_crypto_profile_init()``), providing the number of keyslots.
> +must call ``blk_crypto_profile_alloc()`` (or its resource-managed variant
> +``devm_blk_crypto_profile_alloc()``), providing the number of keyslots.
>
>  Next, it must advertise its crypto capabilities by setting fields in the
>  blk_crypto_profile, e.g. ``modes_supported`` and ``max_dun_bytes_supported``.
> @@ -259,9 +259,9 @@ If there are situations where the inline encryption hardware loses the contents
>  of its keyslots, e.g. device resets, the driver must handle reprogramming the
>  keyslots.  To do this, the driver may call ``blk_crypto_reprogram_all_keys()``.
>
> -Finally, if the driver used ``blk_crypto_profile_init()`` instead of
> -``devm_blk_crypto_profile_init()``, then it is responsible for calling
> -``blk_crypto_profile_destroy()`` when the crypto profile is no longer needed.
> +Finally, if the driver used ``blk_crypto_profile_alloc()`` instead of
> +``devm_blk_crypto_profile_alloc()``, then it is responsible for calling
> +``blk_crypto_profile_put()`` when the crypto profile is no longer needed.
>
>  Layered Devices
>  ===============
> diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
> index 5d1aa5b1d30a1..729974028e448 100644
> --- a/block/blk-crypto-fallback.c
> +++ b/block/blk-crypto-fallback.c
> @@ -78,7 +78,7 @@ static struct blk_crypto_fallback_keyslot {
>         struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
>  } *blk_crypto_keyslots;
>
> -static struct blk_crypto_profile blk_crypto_fallback_profile;
> +static struct blk_crypto_profile *blk_crypto_fallback_profile;
>  static struct workqueue_struct *blk_crypto_wq;
>  static mempool_t *blk_crypto_bounce_page_pool;
>  static struct bio_set crypto_bio_split;
> @@ -293,7 +293,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
>          * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
>          * this bio's algorithm and key.
>          */
> -       blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
> +       blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
>                                         bc->bc_key, &slot);
>         if (blk_st != BLK_STS_OK) {
>                 src_bio->bi_status = blk_st;
> @@ -396,7 +396,7 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
>          * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
>          * this bio's algorithm and key.
>          */
> -       blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
> +       blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
>                                         bc->bc_key, &slot);
>         if (blk_st != BLK_STS_OK) {
>                 bio->bi_status = blk_st;
> @@ -500,7 +500,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
>                 return false;
>         }
>
> -       if (!__blk_crypto_cfg_supported(&blk_crypto_fallback_profile,
> +       if (!__blk_crypto_cfg_supported(blk_crypto_fallback_profile,
>                                         &bc->bc_key->crypto_cfg)) {
>                 bio->bi_status = BLK_STS_NOTSUPP;
>                 return false;
> @@ -527,7 +527,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
>
>  int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
>  {
> -       return __blk_crypto_evict_key(&blk_crypto_fallback_profile, key);
> +       return __blk_crypto_evict_key(blk_crypto_fallback_profile, key);
>  }
>
>  static bool blk_crypto_fallback_inited;
> @@ -535,7 +535,7 @@ static int blk_crypto_fallback_init(void)
>  {
>         int i;
>         int err;
> -       struct blk_crypto_profile *profile = &blk_crypto_fallback_profile;
> +       struct blk_crypto_profile *profile;
>
>         if (blk_crypto_fallback_inited)
>                 return 0;
> @@ -546,10 +546,10 @@ static int blk_crypto_fallback_init(void)
>         if (err)
>                 goto out;
>
> -       err = blk_crypto_profile_init(profile, blk_crypto_num_keyslots);
> -       if (err)
> -               goto fail_free_bioset;
>         err = -ENOMEM;
> +       profile = blk_crypto_profile_alloc(blk_crypto_num_keyslots);
> +       if (!profile)
> +               goto fail_free_bioset;
>
>         profile->ll_ops = blk_crypto_fallback_ll_ops;
>         profile->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
> @@ -598,7 +598,7 @@ static int blk_crypto_fallback_init(void)
>  fail_free_wq:
>         destroy_workqueue(blk_crypto_wq);
>  fail_destroy_profile:
> -       blk_crypto_profile_destroy(profile);
> +       blk_crypto_profile_put(profile);
>  fail_free_bioset:
>         bioset_exit(&crypto_bio_split);
>  out:
> diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c
> index 4f444323cb491..e4e14322d2f2e 100644
> --- a/block/blk-crypto-profile.c
> +++ b/block/blk-crypto-profile.c
> @@ -42,11 +42,6 @@ struct blk_crypto_keyslot {
>         struct blk_crypto_profile *profile;
>  };
>
> -struct blk_crypto_kobj {
> -       struct kobject kobj;
> -       struct blk_crypto_profile *profile;
> -};
> -
>  struct blk_crypto_attr {
>         struct attribute attr;
>         ssize_t (*show)(struct blk_crypto_profile *profile,
> @@ -55,7 +50,7 @@ struct blk_crypto_attr {
>
>  static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
>  {
> -       return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
> +       return container_of(kobj, struct blk_crypto_profile, kobj);
>  }
>
>  static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
> @@ -145,7 +140,14 @@ static const struct sysfs_ops blk_crypto_attr_ops = {
>
>  static void blk_crypto_release(struct kobject *kobj)
>  {
> -       kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
> +       struct blk_crypto_profile *profile =
> +               container_of(kobj, struct blk_crypto_profile, kobj);
> +
> +       kvfree(profile->slot_hashtable);
> +       kvfree_sensitive(profile->slots,
> +                        sizeof(profile->slots[0]) * profile->num_slots);
> +       memzero_explicit(profile, sizeof(*profile));
> +       kfree(profile);
>  }
>
>  static struct kobj_type blk_crypto_ktype = {
> @@ -160,30 +162,20 @@ static struct kobj_type blk_crypto_ktype = {
>   */
>  int blk_crypto_sysfs_register(struct request_queue *q)
>  {
> -       struct blk_crypto_kobj *obj;
>         int err;
>
>         if (!q->crypto_profile)
>                 return 0;
>
> -       obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> -       if (!obj)
> -               return -ENOMEM;
> -       obj->profile = q->crypto_profile;
> -
> -       err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
> -                                  "crypto");
> -       if (err) {
> -               kobject_put(&obj->kobj);
> -               return err;
> -       }
> -       q->crypto_kobject = &obj->kobj;
> -       return 0;
> +       err = kobject_add(&q->crypto_profile->kobj, &q->kobj, "crypto");
> +       if (err)
> +               kobject_put(&q->crypto_profile->kobj);
> +       return err;
>  }
>
>  void blk_crypto_sysfs_unregister(struct request_queue *q)
>  {
> -       kobject_put(q->crypto_kobject);
> +       kobject_del(&q->crypto_profile->kobj);
>  }
>
>  static inline void blk_crypto_hw_enter(struct blk_crypto_profile *profile)
> @@ -205,30 +197,13 @@ static inline void blk_crypto_hw_exit(struct blk_crypto_profile *profile)
>                 pm_runtime_put_sync(profile->dev);
>  }
>
> -/**
> - * blk_crypto_profile_init() - Initialize a blk_crypto_profile
> - * @profile: the blk_crypto_profile to initialize
> - * @num_slots: the number of keyslots
> - *
> - * Storage drivers must call this when starting to set up a blk_crypto_profile,
> - * before filling in additional fields.
> - *
> - * Return: 0 on success, or else a negative error code.
> - */
> -int blk_crypto_profile_init(struct blk_crypto_profile *profile,
> -                           unsigned int num_slots)
> +/* Initialize keyslot management data. */
> +static int blk_crypto_profile_init_slots(struct blk_crypto_profile *profile,
> +               unsigned int num_slots)
>  {
> +       unsigned int slot_hashtable_size;
>         unsigned int slot;
>         unsigned int i;
> -       unsigned int slot_hashtable_size;
> -
> -       memset(profile, 0, sizeof(*profile));
> -       init_rwsem(&profile->lock);
> -
> -       if (num_slots == 0)
> -               return 0;
> -
> -       /* Initialize keyslot management data. */
>
>         profile->slots = kvcalloc(num_slots, sizeof(profile->slots[0]),
>                                   GFP_KERNEL);
> @@ -261,48 +236,75 @@ int blk_crypto_profile_init(struct blk_crypto_profile *profile,
>                 kvmalloc_array(slot_hashtable_size,
>                                sizeof(profile->slot_hashtable[0]), GFP_KERNEL);
>         if (!profile->slot_hashtable)
> -               goto err_destroy;
> +               return -ENOMEM;
>         for (i = 0; i < slot_hashtable_size; i++)
>                 INIT_HLIST_HEAD(&profile->slot_hashtable[i]);
> -
>         return 0;
> +}
> +
> +/**
> + * blk_crypto_profile_alloc() - Allocate a blk_crypto_profile
> + * @num_slots: the number of keyslots
> + *
> + * Storage drivers must call this when starting to set up a blk_crypto_profile,
> + * before filling in additional fields.
> + *
> + * Return: pointer to the profile on success, or ele %NULL.
> + */
> +struct blk_crypto_profile *blk_crypto_profile_alloc(unsigned int num_slots)
> +{
> +       struct blk_crypto_profile *profile;
>
> -err_destroy:
> -       blk_crypto_profile_destroy(profile);
> -       return -ENOMEM;
> +       profile = kzalloc(sizeof(*profile), GFP_KERNEL);
> +       if (!profile)
> +               return NULL;
> +       kobject_init(&profile->kobj, &blk_crypto_ktype);
> +       init_rwsem(&profile->lock);
> +       if (num_slots && blk_crypto_profile_init_slots(profile, num_slots)) {
> +               blk_crypto_profile_put(profile);
> +               return NULL;
> +       }
> +
> +       return profile;
>  }
> -EXPORT_SYMBOL_GPL(blk_crypto_profile_init);
> +EXPORT_SYMBOL_GPL(blk_crypto_profile_alloc);
>
> -static void blk_crypto_profile_destroy_callback(void *profile)
> +void blk_crypto_profile_put(struct blk_crypto_profile *profile)
>  {
> -       blk_crypto_profile_destroy(profile);
> +       if (profile)
> +               kobject_put(&profile->kobj);
> +}
> +EXPORT_SYMBOL_GPL(blk_crypto_profile_put);
> +
> +static void blk_crypto_profile_put_callback(void *profile)
> +{
> +       blk_crypto_profile_put(profile);
>  }
>
>  /**
> - * devm_blk_crypto_profile_init() - Resource-managed blk_crypto_profile_init()
> + * devm_blk_crypto_profile_alloc() - Resource-managed blk_crypto_profile_alloc()
>   * @dev: the device which owns the blk_crypto_profile
> - * @profile: the blk_crypto_profile to initialize
>   * @num_slots: the number of keyslots
>   *
> - * Like blk_crypto_profile_init(), but causes blk_crypto_profile_destroy() to be
> + * Like blk_crypto_profile_alloc(), but causes blk_crypto_profile_put() to be
>   * called automatically on driver detach.
>   *
> - * Return: 0 on success, or else a negative error code.
> + * Return: profile on success, or else %NULL.
>   */
> -int devm_blk_crypto_profile_init(struct device *dev,
> -                                struct blk_crypto_profile *profile,
> +struct blk_crypto_profile *devm_blk_crypto_profile_alloc(struct device *dev,
>                                  unsigned int num_slots)
>  {
> -       int err = blk_crypto_profile_init(profile, num_slots);
> -
> -       if (err)
> -               return err;
> +       struct blk_crypto_profile *profile;
>
> -       return devm_add_action_or_reset(dev,
> -                                       blk_crypto_profile_destroy_callback,
> -                                       profile);
> +       profile = blk_crypto_profile_alloc(num_slots);
> +       if (!profile)
> +               return NULL;
> +       if (devm_add_action_or_reset(dev, blk_crypto_profile_put_callback,
> +                       profile))
> +               return NULL;
> +       return profile;
>  }
> -EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_init);
> +EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_alloc);
>
>  static inline struct hlist_head *
>  blk_crypto_hash_bucket_for_key(struct blk_crypto_profile *profile,
> @@ -585,17 +587,6 @@ void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile)
>  }
>  EXPORT_SYMBOL_GPL(blk_crypto_reprogram_all_keys);
>
> -void blk_crypto_profile_destroy(struct blk_crypto_profile *profile)
> -{
> -       if (!profile)
> -               return;
> -       kvfree(profile->slot_hashtable);
> -       kvfree_sensitive(profile->slots,
> -                        sizeof(profile->slots[0]) * profile->num_slots);
> -       memzero_explicit(profile, sizeof(*profile));
> -}
> -EXPORT_SYMBOL_GPL(blk_crypto_profile_destroy);
> -
>  bool blk_crypto_register(struct blk_crypto_profile *profile,
>                          struct request_queue *q)
>  {
> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> index e7d42f6335a2a..0d40f9e9eefbc 100644
> --- a/drivers/md/dm-table.c
> +++ b/drivers/md/dm-table.c
> @@ -1185,11 +1185,6 @@ static int dm_table_register_integrity(struct dm_table *t)
>
>  #ifdef CONFIG_BLK_INLINE_ENCRYPTION
>
> -struct dm_crypto_profile {
> -       struct blk_crypto_profile profile;
> -       struct mapped_device *md;
> -};
> -
>  struct dm_keyslot_evict_args {
>         const struct blk_crypto_key *key;
>         int err;
> @@ -1215,8 +1210,7 @@ static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
>  static int dm_keyslot_evict(struct blk_crypto_profile *profile,
>                             const struct blk_crypto_key *key, unsigned int slot)
>  {
> -       struct mapped_device *md =
> -               container_of(profile, struct dm_crypto_profile, profile)->md;
> +       struct mapped_device *md = profile->private;
>         struct dm_keyslot_evict_args args = { key };
>         struct dm_table *t;
>         int srcu_idx;
> @@ -1250,15 +1244,7 @@ device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
>
>  void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
>  {
> -       struct dm_crypto_profile *dmcp = container_of(profile,
> -                                                     struct dm_crypto_profile,
> -                                                     profile);
> -
> -       if (!profile)
> -               return;
> -
> -       blk_crypto_profile_destroy(profile);
> -       kfree(dmcp);
> +       blk_crypto_profile_put(profile);
>  }
>
>  static void dm_table_destroy_crypto_profile(struct dm_table *t)
> @@ -1278,19 +1264,15 @@ static void dm_table_destroy_crypto_profile(struct dm_table *t)
>   */
>  static int dm_table_construct_crypto_profile(struct dm_table *t)
>  {
> -       struct dm_crypto_profile *dmcp;
>         struct blk_crypto_profile *profile;
>         struct dm_target *ti;
>         unsigned int i;
>         bool empty_profile = true;
>
> -       dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
> -       if (!dmcp)
> +       profile = blk_crypto_profile_alloc(0);
> +       if (!profile)
>                 return -ENOMEM;
> -       dmcp->md = t->md;
> -
> -       profile = &dmcp->profile;
> -       blk_crypto_profile_init(profile, 0);
> +       profile->private = t->md;
>         profile->ll_ops.keyslot_evict = dm_keyslot_evict;
>         profile->max_dun_bytes_supported = UINT_MAX;
>         memset(profile->modes_supported, 0xFF,
> diff --git a/drivers/mmc/core/crypto.c b/drivers/mmc/core/crypto.c
> index fec4fbf16a5b6..df3c002526cc7 100644
> --- a/drivers/mmc/core/crypto.c
> +++ b/drivers/mmc/core/crypto.c
> @@ -16,13 +16,13 @@ void mmc_crypto_set_initial_state(struct mmc_host *host)
>  {
>         /* Reset might clear all keys, so reprogram all the keys. */
>         if (host->caps2 & MMC_CAP2_CRYPTO)
> -               blk_crypto_reprogram_all_keys(&host->crypto_profile);
> +               blk_crypto_reprogram_all_keys(host->crypto_profile);
>  }
>
>  void mmc_crypto_setup_queue(struct request_queue *q, struct mmc_host *host)
>  {
>         if (host->caps2 & MMC_CAP2_CRYPTO)
> -               blk_crypto_register(&host->crypto_profile, q);
> +               blk_crypto_register(host->crypto_profile, q);
>  }
>  EXPORT_SYMBOL_GPL(mmc_crypto_setup_queue);
>
> diff --git a/drivers/mmc/host/cqhci-crypto.c b/drivers/mmc/host/cqhci-crypto.c
> index d5f4b6972f63e..6b1c111e9e4b2 100644
> --- a/drivers/mmc/host/cqhci-crypto.c
> +++ b/drivers/mmc/host/cqhci-crypto.c
> @@ -25,8 +25,7 @@ static const struct cqhci_crypto_alg_entry {
>  static inline struct cqhci_host *
>  cqhci_host_from_crypto_profile(struct blk_crypto_profile *profile)
>  {
> -       struct mmc_host *mmc =
> -               container_of(profile, struct mmc_host, crypto_profile);
> +       struct mmc_host *mmc = profile->private;
>
>         return mmc->cqe_private;
>  }
> @@ -169,7 +168,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
>  {
>         struct mmc_host *mmc = cq_host->mmc;
>         struct device *dev = mmc_dev(mmc);
> -       struct blk_crypto_profile *profile = &mmc->crypto_profile;
> +       struct blk_crypto_profile *profile;
>         unsigned int num_keyslots;
>         unsigned int cap_idx;
>         enum blk_crypto_mode_num blk_mode_num;
> @@ -180,6 +179,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
>             !(cqhci_readl(cq_host, CQHCI_CAP) & CQHCI_CAP_CS))
>                 goto out;
>
> +       err = -ENOMEM;
>         cq_host->crypto_capabilities.reg_val =
>                         cpu_to_le32(cqhci_readl(cq_host, CQHCI_CCAP));
>
> @@ -189,10 +189,8 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
>         cq_host->crypto_cap_array =
>                 devm_kcalloc(dev, cq_host->crypto_capabilities.num_crypto_cap,
>                              sizeof(cq_host->crypto_cap_array[0]), GFP_KERNEL);
> -       if (!cq_host->crypto_cap_array) {
> -               err = -ENOMEM;
> +       if (!cq_host->crypto_cap_array)
>                 goto out;
> -       }
>
>         /*
>          * CCAP.CFGC is off by one, so the actual number of crypto
> @@ -200,10 +198,10 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
>          */
>         num_keyslots = cq_host->crypto_capabilities.config_count + 1;
>
> -       err = devm_blk_crypto_profile_init(dev, profile, num_keyslots);
> -       if (err)
> +       profile = devm_blk_crypto_profile_alloc(dev, num_keyslots);
> +       if (!profile)
>                 goto out;
> -
> +       profile->private = mmc;
>         profile->ll_ops = cqhci_crypto_ops;
>         profile->dev = dev;
>
> diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
> index 67402baf6faee..b48ff6046bdc8 100644
> --- a/drivers/scsi/ufs/ufshcd-crypto.c
> +++ b/drivers/scsi/ufs/ufshcd-crypto.c
> @@ -52,8 +52,7 @@ static int ufshcd_crypto_keyslot_program(struct blk_crypto_profile *profile,
>                                          const struct blk_crypto_key *key,
>                                          unsigned int slot)
>  {
> -       struct ufs_hba *hba =
> -               container_of(profile, struct ufs_hba, crypto_profile);
> +       struct ufs_hba *hba = profile->private;
>         const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
>         const struct ufs_crypto_alg_entry *alg =
>                         &ufs_crypto_algs[key->crypto_cfg.crypto_mode];
> @@ -110,10 +109,7 @@ static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
>                                        const struct blk_crypto_key *key,
>                                        unsigned int slot)
>  {
> -       struct ufs_hba *hba =
> -               container_of(profile, struct ufs_hba, crypto_profile);
> -
> -       return ufshcd_clear_keyslot(hba, slot);
> +       return ufshcd_clear_keyslot(profile->private, slot);
>  }
>
>  bool ufshcd_crypto_enable(struct ufs_hba *hba)
> @@ -122,7 +118,7 @@ bool ufshcd_crypto_enable(struct ufs_hba *hba)
>                 return false;
>
>         /* Reset might clear all keys, so reprogram all the keys. */
> -       blk_crypto_reprogram_all_keys(&hba->crypto_profile);
> +       blk_crypto_reprogram_all_keys(hba->crypto_profile);
>         return true;
>  }
>
> @@ -168,6 +164,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
>             !(hba->caps & UFSHCD_CAP_CRYPTO))
>                 goto out;
>
> +       err = -ENOMEM;
>         hba->crypto_capabilities.reg_val =
>                         cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
>         hba->crypto_cfg_register =
> @@ -175,22 +172,20 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
>         hba->crypto_cap_array =
>                 devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
>                              sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
> -       if (!hba->crypto_cap_array) {
> -               err = -ENOMEM;
> +       if (!hba->crypto_cap_array)
>                 goto out;
> -       }
>
>         /* The actual number of configurations supported is (CFGC+1) */
> -       err = devm_blk_crypto_profile_init(
> -                       hba->dev, &hba->crypto_profile,
> +       hba->crypto_profile = devm_blk_crypto_profile_alloc(hba->dev,
>                         hba->crypto_capabilities.config_count + 1);
> -       if (err)
> +       if (!hba->crypto_profile)
>                 goto out;
>
> -       hba->crypto_profile.ll_ops = ufshcd_crypto_ops;
> +       hba->crypto_profile->private = hba;
> +       hba->crypto_profile->ll_ops = ufshcd_crypto_ops;
>         /* UFS only supports 8 bytes for any DUN */
> -       hba->crypto_profile.max_dun_bytes_supported = 8;
> -       hba->crypto_profile.dev = hba->dev;
> +       hba->crypto_profile->max_dun_bytes_supported = 8;
> +       hba->crypto_profile->dev = hba->dev;
>
>         /*
>          * Cache all the UFS crypto capabilities and advertise the supported
> @@ -205,7 +200,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
>                 blk_mode_num = ufshcd_find_blk_crypto_mode(
>                                                 hba->crypto_cap_array[cap_idx]);
>                 if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
> -                       hba->crypto_profile.modes_supported[blk_mode_num] |=
> +                       hba->crypto_profile->modes_supported[blk_mode_num] |=
>                                 hba->crypto_cap_array[cap_idx].sdus_mask * 512;
>         }
>
> @@ -236,5 +231,5 @@ void ufshcd_init_crypto(struct ufs_hba *hba)
>  void ufshcd_crypto_register(struct ufs_hba *hba, struct request_queue *q)
>  {
>         if (hba->caps & UFSHCD_CAP_CRYPTO)
> -               blk_crypto_register(&hba->crypto_profile, q);
> +               blk_crypto_register(hba->crypto_profile, q);
>  }
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 94f545be183aa..94edbe3721890 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -930,7 +930,7 @@ struct ufs_hba {
>         union ufs_crypto_capabilities crypto_capabilities;
>         union ufs_crypto_cap_entry *crypto_cap_array;
>         u32 crypto_cfg_register;
> -       struct blk_crypto_profile crypto_profile;
> +       struct blk_crypto_profile *crypto_profile;
>  #endif
>  #ifdef CONFIG_DEBUG_FS
>         struct dentry *debugfs_root;
> diff --git a/include/linux/blk-crypto-profile.h b/include/linux/blk-crypto-profile.h
> index bbab65bd54288..07745a4675f25 100644
> --- a/include/linux/blk-crypto-profile.h
> +++ b/include/linux/blk-crypto-profile.h
> @@ -8,6 +8,7 @@
>
>  #include <linux/bio.h>
>  #include <linux/blk-crypto.h>
> +#include <linux/kobject.h>
>
>  struct blk_crypto_profile;
>
> @@ -100,6 +101,11 @@ struct blk_crypto_profile {
>          */
>         struct device *dev;
>
> +       /**
> +        * @private: Optional private data for driver use.
> +        */
> +       void *private;
> +
>         /* private: The following fields shouldn't be accessed by drivers. */
>
>         /* Number of keyslots, or 0 if not applicable */
> @@ -127,14 +133,13 @@ struct blk_crypto_profile {
>
>         /* Per-keyslot data */
>         struct blk_crypto_keyslot *slots;
> -};
>
> -int blk_crypto_profile_init(struct blk_crypto_profile *profile,
> -                           unsigned int num_slots);
> +       struct kobject kobj;
> +};
>
> -int devm_blk_crypto_profile_init(struct device *dev,
> -                                struct blk_crypto_profile *profile,
> -                                unsigned int num_slots);
> +struct blk_crypto_profile *blk_crypto_profile_alloc(unsigned int num_slots);
> +struct blk_crypto_profile *devm_blk_crypto_profile_alloc(struct device *dev,
> +               unsigned int num_slots);
>
>  unsigned int blk_crypto_keyslot_index(struct blk_crypto_keyslot *slot);
>
> @@ -152,7 +157,7 @@ int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
>
>  void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile);
>
> -void blk_crypto_profile_destroy(struct blk_crypto_profile *profile);
> +void blk_crypto_profile_put(struct blk_crypto_profile *profile);
>
>  void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent,
>                                        const struct blk_crypto_profile *child);
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 34724b15813b7..390e3c4ad64b6 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -413,7 +413,6 @@ struct request_queue {
>
>  #ifdef CONFIG_BLK_INLINE_ENCRYPTION
>         struct blk_crypto_profile *crypto_profile;
> -       struct kobject *crypto_kobject;
>  #endif
>
>         unsigned int            rq_timeout;
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 7afb57cab00b7..8d6069503c0dc 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -495,7 +495,7 @@ struct mmc_host {
>
>         /* Inline encryption support */
>  #ifdef CONFIG_MMC_CRYPTO
> -       struct blk_crypto_profile crypto_profile;
> +       struct blk_crypto_profile *crypto_profile;
>  #endif
>
>         /* Host Software Queue support */
> --
> 2.30.2
>

Re: [dm-devel] [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Eric Biggers]

On Wed, Apr 20, 2022 at 08:47:45AM +0200, Christoph Hellwig wrote:
> Once the blk_crypto_profile is exposed in sysfs it needs to stay alive
> as long as sysfs accesses are possibly pending.  Ensure that by removing
> the blk_crypto_kobj wrapper and just embedding the kobject into the
> actual blk_crypto_profile.  This requires the blk_crypto_profile
> structure to be dynamically allocated, which in turn requires a private
> data pointer for driver use.
> 
> Fixes: 20f01f163203 ("blk-crypto: show crypto capabilities in sysfs")
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Can you elaborate on what you think the actual problem is here?  The lifetime of
the blk_crypto_profile matches that of the host controller kobject, and I
thought that it is not destroyed until after higher-level objects such as
gendisks and request_queues are destroyed.  Similar assumptions are made by the
queue kobject, which assumes it is safe to access the gendisk, and by the
independent_access_ranges kobject which assumes it is safe to access the queue.

I suppose this wouldn't have worked with the original sysfs design where opening
a file in sysfs actually got a refcount to the kobject.  But that's long gone,
having been changed in Linux v2.6.23 (https://lwn.net/Articles/229774).

Note that commit 20f01f163203 which added this code got an "all looks good" from
Greg KH (https://lore.kernel.org/r/YaH1CmHClx5WvDWD@kroah.com).  I'd have hoped
that he would've noticed if there was a major problem with how kobjects are used
here!  Greg, would you mind taking a look at this part again?

>  int blk_crypto_sysfs_register(struct request_queue *q)
>  {
> -	struct blk_crypto_kobj *obj;
>  	int err;
>  
>  	if (!q->crypto_profile)
>  		return 0;
>  
> -	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> -	if (!obj)
> -		return -ENOMEM;
> -	obj->profile = q->crypto_profile;
> -
> -	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
> -				   "crypto");
> -	if (err) {
> -		kobject_put(&obj->kobj);
> -		return err;
> -	}
> -	q->crypto_kobject = &obj->kobj;
> -	return 0;
> +	err = kobject_add(&q->crypto_profile->kobj, &q->kobj, "crypto");
> +	if (err)
> +		kobject_put(&q->crypto_profile->kobj);
> +	return err;
>  }

In any case, this proposal is not correct since it is assuming that each
blk_crypto_profile is referenced by only one request_queue, which is not
necessarily the case since a host controller can have multiple disks.
The same kobject can't be added to multiple places in the hierarchy.

If we did need to do something differently here, I think we'd either need to put
the blk_crypto_profile kobject under the host controller one and link to it from
the queue directories (which I mentioned in commit 20f01f163203 as an
alternative considered), or duplicate the crypto capabilities in each
request_queue and only share the actual keyslot management data structures.

- Eric

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Re: [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Eric Biggers]

On Wed, Apr 20, 2022 at 08:47:45AM +0200, Christoph Hellwig wrote:
> Once the blk_crypto_profile is exposed in sysfs it needs to stay alive
> as long as sysfs accesses are possibly pending.  Ensure that by removing
> the blk_crypto_kobj wrapper and just embedding the kobject into the
> actual blk_crypto_profile.  This requires the blk_crypto_profile
> structure to be dynamically allocated, which in turn requires a private
> data pointer for driver use.
> 
> Fixes: 20f01f163203 ("blk-crypto: show crypto capabilities in sysfs")
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Can you elaborate on what you think the actual problem is here?  The lifetime of
the blk_crypto_profile matches that of the host controller kobject, and I
thought that it is not destroyed until after higher-level objects such as
gendisks and request_queues are destroyed.  Similar assumptions are made by the
queue kobject, which assumes it is safe to access the gendisk, and by the
independent_access_ranges kobject which assumes it is safe to access the queue.

I suppose this wouldn't have worked with the original sysfs design where opening
a file in sysfs actually got a refcount to the kobject.  But that's long gone,
having been changed in Linux v2.6.23 (https://lwn.net/Articles/229774).

Note that commit 20f01f163203 which added this code got an "all looks good" from
Greg KH (https://lore.kernel.org/r/YaH1CmHClx5WvDWD@kroah.com).  I'd have hoped
that he would've noticed if there was a major problem with how kobjects are used
here!  Greg, would you mind taking a look at this part again?

>  int blk_crypto_sysfs_register(struct request_queue *q)
>  {
> -	struct blk_crypto_kobj *obj;
>  	int err;
>  
>  	if (!q->crypto_profile)
>  		return 0;
>  
> -	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> -	if (!obj)
> -		return -ENOMEM;
> -	obj->profile = q->crypto_profile;
> -
> -	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
> -				   "crypto");
> -	if (err) {
> -		kobject_put(&obj->kobj);
> -		return err;
> -	}
> -	q->crypto_kobject = &obj->kobj;
> -	return 0;
> +	err = kobject_add(&q->crypto_profile->kobj, &q->kobj, "crypto");
> +	if (err)
> +		kobject_put(&q->crypto_profile->kobj);
> +	return err;
>  }

In any case, this proposal is not correct since it is assuming that each
blk_crypto_profile is referenced by only one request_queue, which is not
necessarily the case since a host controller can have multiple disks.
The same kobject can't be added to multiple places in the hierarchy.

If we did need to do something differently here, I think we'd either need to put
the blk_crypto_profile kobject under the host controller one and link to it from
the queue directories (which I mentioned in commit 20f01f163203 as an
alternative considered), or duplicate the crypto capabilities in each
request_queue and only share the actual keyslot management data structures.

- Eric

Re: [dm-devel] [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Christoph Hellwig]

On Wed, Apr 20, 2022 at 12:41:53PM -0700, Eric Biggers wrote:
> Can you elaborate on what you think the actual problem is here?  The lifetime of
> the blk_crypto_profile matches that of the host controller kobject, and I
> thought that it is not destroyed until after higher-level objects such as
> gendisks and request_queues are destroyed.

I don't think all driver authors agree with that assumption (and it isn't
documented anywhere). 

The most trivial case is device mapper, where the crypto profіle is freed
before putting the gendisk reference acquired by blk_alloc_disk.  So
anyone who opened the sysfs file at some point before the delete can
still have it open and triviall access freed memory when then doing
a read on it after the dm table is freed.

For UFS things seem to work out ok because the ufs_hba is part of
the Scsi_Host, which is the parent device of the gendisk.

> Similar assumptions are made by the
> queue kobject, which assumes it is safe to access the gendisk, and by the
> independent_access_ranges kobject which assumes it is safe to access the queue.

Yes, every queue/ object that references the gendisk has a problem I think.
I've been wading through this code and trying to fix it, which made me
notice this code.

> In any case, this proposal is not correct since it is assuming that each
> blk_crypto_profile is referenced by only one request_queue, which is not
> necessarily the case since a host controller can have multiple disks.
> The same kobject can't be added to multiple places in the hierarchy.

Indeed.

> If we did need to do something differently here, I think we'd either need to put
> the blk_crypto_profile kobject under the host controller one and link to it from
> the queue directories (which I mentioned in commit 20f01f163203 as an
> alternative considered), or duplicate the crypto capabilities in each
> request_queue and only share the actual keyslot management data structures.

Do we even need the link instead of letting the user walk down the
directory hierachy?  But yes, having the sysfs attributes on the
actual object is a much better idea.

> 
> - Eric
---end quoted text---

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Re: [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Christoph Hellwig]

On Wed, Apr 20, 2022 at 12:41:53PM -0700, Eric Biggers wrote:
> Can you elaborate on what you think the actual problem is here?  The lifetime of
> the blk_crypto_profile matches that of the host controller kobject, and I
> thought that it is not destroyed until after higher-level objects such as
> gendisks and request_queues are destroyed.

I don't think all driver authors agree with that assumption (and it isn't
documented anywhere). 

The most trivial case is device mapper, where the crypto profіle is freed
before putting the gendisk reference acquired by blk_alloc_disk.  So
anyone who opened the sysfs file at some point before the delete can
still have it open and triviall access freed memory when then doing
a read on it after the dm table is freed.

For UFS things seem to work out ok because the ufs_hba is part of
the Scsi_Host, which is the parent device of the gendisk.

> Similar assumptions are made by the
> queue kobject, which assumes it is safe to access the gendisk, and by the
> independent_access_ranges kobject which assumes it is safe to access the queue.

Yes, every queue/ object that references the gendisk has a problem I think.
I've been wading through this code and trying to fix it, which made me
notice this code.

> In any case, this proposal is not correct since it is assuming that each
> blk_crypto_profile is referenced by only one request_queue, which is not
> necessarily the case since a host controller can have multiple disks.
> The same kobject can't be added to multiple places in the hierarchy.

Indeed.

> If we did need to do something differently here, I think we'd either need to put
> the blk_crypto_profile kobject under the host controller one and link to it from
> the queue directories (which I mentioned in commit 20f01f163203 as an
> alternative considered), or duplicate the crypto capabilities in each
> request_queue and only share the actual keyslot management data structures.

Do we even need the link instead of letting the user walk down the
directory hierachy?  But yes, having the sysfs attributes on the
actual object is a much better idea.

> 
> - Eric
---end quoted text---

Re: [dm-devel] [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Eric Biggers]

On Thu, Apr 21, 2022 at 04:25:35PM +0200, Christoph Hellwig wrote:
> On Wed, Apr 20, 2022 at 12:41:53PM -0700, Eric Biggers wrote:
> > Can you elaborate on what you think the actual problem is here?  The lifetime of
> > the blk_crypto_profile matches that of the host controller kobject, and I
> > thought that it is not destroyed until after higher-level objects such as
> > gendisks and request_queues are destroyed.
> 
> I don't think all driver authors agree with that assumption (and it isn't
> documented anywhere). 
> 
> The most trivial case is device mapper, where the crypto profіle is freed
> before putting the gendisk reference acquired by blk_alloc_disk.  So
> anyone who opened the sysfs file at some point before the delete can
> still have it open and triviall access freed memory when then doing
> a read on it after the dm table is freed.
> 
> For UFS things seem to work out ok because the ufs_hba is part of
> the Scsi_Host, which is the parent device of the gendisk.

I tried to reproduce a use-after-free in the device-mapper case, and it doesn't
seem to be possible.  What actually happens is that before freeing the crypto
profile, cleanup_mapped_device() calls del_gendisk(), which deletes the disk
kobject and everything underneath it.  That not only deletes the corresponding
sysfs hierarchy, but also "deactivates" it such that even if a file descriptor
is open to one of the files, attempts to read from it fail with ENODEV.   (It
also waits for any ongoing reads to complete.)

The reference to the disk kobject is indeed released after the crypto profile is
freed, but that doesn't matter as far as sysfs is concerned.

It doesn't appear that concurrent I/O can be a problem either, as the
device-mapper subsystem doesn't allow devices to be deleted while they are open.

It's probably still worth flipping the order of
dm_queue_destroy_crypto_profile() and blk_cleanup_disk() anyway so that it's
less fragile and more similar to the real device drivers, though.

> > Similar assumptions are made by the
> > queue kobject, which assumes it is safe to access the gendisk, and by the
> > independent_access_ranges kobject which assumes it is safe to access the queue.
> 
> Yes, every queue/ object that references the gendisk has a problem I think.
> I've been wading through this code and trying to fix it, which made me
> notice this code.

Based on how sysfs works above, with the entire hierarchy being deactivated by
del_gendisk(), I'm not sure this is really a problem either.

> > In any case, this proposal is not correct since it is assuming that each
> > blk_crypto_profile is referenced by only one request_queue, which is not
> > necessarily the case since a host controller can have multiple disks.
> > The same kobject can't be added to multiple places in the hierarchy.
> 
> Indeed.
> 
> > If we did need to do something differently here, I think we'd either need to put
> > the blk_crypto_profile kobject under the host controller one and link to it from
> > the queue directories (which I mentioned in commit 20f01f163203 as an
> > alternative considered), or duplicate the crypto capabilities in each
> > request_queue and only share the actual keyslot management data structures.
> 
> Do we even need the link instead of letting the user walk down the
> directory hierachy?  But yes, having the sysfs attributes on the
> actual object is a much better idea.

The directories would be in different places for different kind of devices (dm,
ufs, mmc, etc.).  I think we really do need the crypto properties in the queue
directory, otherwise it would be a pain for userspace to actually use them.  (It
could also be the disk directory, but the queue directory is what I chose since
that's where most of the other generic block properties related to I/O are.)

If we did add the properties to the device directories (dm, ufs, mmc, etc.) too,
we'd also have to support them there forever in case someone started using them
(which would be uncommon since they would be a pain to use, but someone will do
it anyway), so we should be careful about that.  I think generic block layer
attributes are really the right way to go here.

- Eric

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Re: [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Eric Biggers]

On Thu, Apr 21, 2022 at 04:25:35PM +0200, Christoph Hellwig wrote:
> On Wed, Apr 20, 2022 at 12:41:53PM -0700, Eric Biggers wrote:
> > Can you elaborate on what you think the actual problem is here?  The lifetime of
> > the blk_crypto_profile matches that of the host controller kobject, and I
> > thought that it is not destroyed until after higher-level objects such as
> > gendisks and request_queues are destroyed.
> 
> I don't think all driver authors agree with that assumption (and it isn't
> documented anywhere). 
> 
> The most trivial case is device mapper, where the crypto profіle is freed
> before putting the gendisk reference acquired by blk_alloc_disk.  So
> anyone who opened the sysfs file at some point before the delete can
> still have it open and triviall access freed memory when then doing
> a read on it after the dm table is freed.
> 
> For UFS things seem to work out ok because the ufs_hba is part of
> the Scsi_Host, which is the parent device of the gendisk.

I tried to reproduce a use-after-free in the device-mapper case, and it doesn't
seem to be possible.  What actually happens is that before freeing the crypto
profile, cleanup_mapped_device() calls del_gendisk(), which deletes the disk
kobject and everything underneath it.  That not only deletes the corresponding
sysfs hierarchy, but also "deactivates" it such that even if a file descriptor
is open to one of the files, attempts to read from it fail with ENODEV.   (It
also waits for any ongoing reads to complete.)

The reference to the disk kobject is indeed released after the crypto profile is
freed, but that doesn't matter as far as sysfs is concerned.

It doesn't appear that concurrent I/O can be a problem either, as the
device-mapper subsystem doesn't allow devices to be deleted while they are open.

It's probably still worth flipping the order of
dm_queue_destroy_crypto_profile() and blk_cleanup_disk() anyway so that it's
less fragile and more similar to the real device drivers, though.

> > Similar assumptions are made by the
> > queue kobject, which assumes it is safe to access the gendisk, and by the
> > independent_access_ranges kobject which assumes it is safe to access the queue.
> 
> Yes, every queue/ object that references the gendisk has a problem I think.
> I've been wading through this code and trying to fix it, which made me
> notice this code.

Based on how sysfs works above, with the entire hierarchy being deactivated by
del_gendisk(), I'm not sure this is really a problem either.

> > In any case, this proposal is not correct since it is assuming that each
> > blk_crypto_profile is referenced by only one request_queue, which is not
> > necessarily the case since a host controller can have multiple disks.
> > The same kobject can't be added to multiple places in the hierarchy.
> 
> Indeed.
> 
> > If we did need to do something differently here, I think we'd either need to put
> > the blk_crypto_profile kobject under the host controller one and link to it from
> > the queue directories (which I mentioned in commit 20f01f163203 as an
> > alternative considered), or duplicate the crypto capabilities in each
> > request_queue and only share the actual keyslot management data structures.
> 
> Do we even need the link instead of letting the user walk down the
> directory hierachy?  But yes, having the sysfs attributes on the
> actual object is a much better idea.

The directories would be in different places for different kind of devices (dm,
ufs, mmc, etc.).  I think we really do need the crypto properties in the queue
directory, otherwise it would be a pain for userspace to actually use them.  (It
could also be the disk directory, but the queue directory is what I chose since
that's where most of the other generic block properties related to I/O are.)

If we did add the properties to the device directories (dm, ufs, mmc, etc.) too,
we'd also have to support them there forever in case someone started using them
(which would be uncommon since they would be a pain to use, but someone will do
it anyway), so we should be careful about that.  I think generic block layer
attributes are really the right way to go here.

- Eric

Re: [dm-devel] [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Greg Kroah-Hartman]

On Wed, Apr 20, 2022 at 12:41:53PM -0700, Eric Biggers wrote:
> On Wed, Apr 20, 2022 at 08:47:45AM +0200, Christoph Hellwig wrote:
> > Once the blk_crypto_profile is exposed in sysfs it needs to stay alive
> > as long as sysfs accesses are possibly pending.  Ensure that by removing
> > the blk_crypto_kobj wrapper and just embedding the kobject into the
> > actual blk_crypto_profile.  This requires the blk_crypto_profile
> > structure to be dynamically allocated, which in turn requires a private
> > data pointer for driver use.
> > 
> > Fixes: 20f01f163203 ("blk-crypto: show crypto capabilities in sysfs")
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Can you elaborate on what you think the actual problem is here?  The lifetime of
> the blk_crypto_profile matches that of the host controller kobject, and I
> thought that it is not destroyed until after higher-level objects such as
> gendisks and request_queues are destroyed.  Similar assumptions are made by the
> queue kobject, which assumes it is safe to access the gendisk, and by the
> independent_access_ranges kobject which assumes it is safe to access the queue.
> 
> I suppose this wouldn't have worked with the original sysfs design where opening
> a file in sysfs actually got a refcount to the kobject.  But that's long gone,
> having been changed in Linux v2.6.23 (https://lwn.net/Articles/229774).
> 
> Note that commit 20f01f163203 which added this code got an "all looks good" from
> Greg KH (https://lore.kernel.org/r/YaH1CmHClx5WvDWD@kroah.com).  I'd have hoped
> that he would've noticed if there was a major problem with how kobjects are used
> here!  Greg, would you mind taking a look at this part again?

I do not know the model for the block devices and queues and all of that
well at all.  My first glance this seemed sane, but if the lifetime
rules are not normal in any way, I do not know.  I defer to Christoph
for all of this, he knows it way better than I do.

thanks,

greg k-h

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Re: [PATCH 2/2] blk-crypto: fix the blk_crypto_profile liftime

[Greg Kroah-Hartman]

On Wed, Apr 20, 2022 at 12:41:53PM -0700, Eric Biggers wrote:
> On Wed, Apr 20, 2022 at 08:47:45AM +0200, Christoph Hellwig wrote:
> > Once the blk_crypto_profile is exposed in sysfs it needs to stay alive
> > as long as sysfs accesses are possibly pending.  Ensure that by removing
> > the blk_crypto_kobj wrapper and just embedding the kobject into the
> > actual blk_crypto_profile.  This requires the blk_crypto_profile
> > structure to be dynamically allocated, which in turn requires a private
> > data pointer for driver use.
> > 
> > Fixes: 20f01f163203 ("blk-crypto: show crypto capabilities in sysfs")
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Can you elaborate on what you think the actual problem is here?  The lifetime of
> the blk_crypto_profile matches that of the host controller kobject, and I
> thought that it is not destroyed until after higher-level objects such as
> gendisks and request_queues are destroyed.  Similar assumptions are made by the
> queue kobject, which assumes it is safe to access the gendisk, and by the
> independent_access_ranges kobject which assumes it is safe to access the queue.
> 
> I suppose this wouldn't have worked with the original sysfs design where opening
> a file in sysfs actually got a refcount to the kobject.  But that's long gone,
> having been changed in Linux v2.6.23 (https://lwn.net/Articles/229774).
> 
> Note that commit 20f01f163203 which added this code got an "all looks good" from
> Greg KH (https://lore.kernel.org/r/YaH1CmHClx5WvDWD@kroah.com).  I'd have hoped
> that he would've noticed if there was a major problem with how kobjects are used
> here!  Greg, would you mind taking a look at this part again?

I do not know the model for the block devices and queues and all of that
well at all.  My first glance this seemed sane, but if the lifetime
rules are not normal in any way, I do not know.  I defer to Christoph
for all of this, he knows it way better than I do.

thanks,

greg k-h