1 files changed, 952 insertions, 106 deletions

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index ac33d5f30778..e468714f539d 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -1,15 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * af_alg: User-space algorithm interface
  *
  * This file provides the user-space API for algorithms.
  *
  * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 2 of the License, or (at your option)
- * any later version.
- *
  */
 
 #include <linux/atomic.h>
@@ -17,22 +12,28 @@
 #include <linux/crypto.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/key.h>
+#include <linux/key-type.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/net.h>
 #include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/security.h>
+#include <linux/string.h>
+#include <keys/user-type.h>
+#include <keys/trusted-type.h>
+#include <keys/encrypted-type.h>
 
 struct alg_type_list {
 	const struct af_alg_type *type;
 	struct list_head list;
 };
 
-static atomic_long_t alg_memory_allocated;
-
 static struct proto alg_proto = {
 	.name			= "ALG",
 	.owner			= THIS_MODULE,
-	.memory_allocated	= &alg_memory_allocated,
 	.obj_size		= sizeof(struct alg_sock),
 };
 
@@ -75,6 +76,8 @@ int af_alg_register_type(const struct af_alg_type *type)
 		goto unlock;
 
 	type->ops->owner = THIS_MODULE;
+	if (type->ops_nokey)
+		type->ops_nokey->owner = THIS_MODULE;
 	node->type = type;
 	list_add(&node->list, &alg_types);
 	err = 0;
@@ -118,31 +121,59 @@ static void alg_do_release(const struct af_alg_type *type, void *private)
 
 int af_alg_release(struct socket *sock)
 {
-	if (sock->sk)
+	if (sock->sk) {
 		sock_put(sock->sk);
+		sock->sk = NULL;
+	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(af_alg_release);
 
-static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
+void af_alg_release_parent(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	unsigned int nokey = atomic_read(&ask->nokey_refcnt);
+
+	sk = ask->parent;
+	ask = alg_sk(sk);
+
+	if (nokey)
+		atomic_dec(&ask->nokey_refcnt);
+
+	if (atomic_dec_and_test(&ask->refcnt))
+		sock_put(sk);
+}
+EXPORT_SYMBOL_GPL(af_alg_release_parent);
+
+static int alg_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len)
 {
+	const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
-	struct sockaddr_alg *sa = (void *)uaddr;
+	struct sockaddr_alg_new *sa = (void *)uaddr;
 	const struct af_alg_type *type;
 	void *private;
+	int err;
 
 	if (sock->state == SS_CONNECTED)
 		return -EINVAL;
 
-	if (addr_len != sizeof(*sa))
+	BUILD_BUG_ON(offsetof(struct sockaddr_alg_new, salg_name) !=
+		     offsetof(struct sockaddr_alg, salg_name));
+	BUILD_BUG_ON(offsetof(struct sockaddr_alg, salg_name) != sizeof(*sa));
+
+	if (addr_len < sizeof(*sa) + 1)
+		return -EINVAL;
+
+	/* If caller uses non-allowed flag, return error. */
+	if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
 		return -EINVAL;
 
 	sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
-	sa->salg_name[sizeof(sa->salg_name) - 1] = 0;
+	sa->salg_name[addr_len - sizeof(*sa) - 1] = 0;
 
 	type = alg_get_type(sa->salg_type);
-	if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
+	if (PTR_ERR(type) == -ENOENT) {
 		request_module("algif-%s", sa->salg_type);
 		type = alg_get_type(sa->salg_type);
 	}
@@ -156,20 +187,25 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		return PTR_ERR(private);
 	}
 
+	err = -EBUSY;
 	lock_sock(sk);
+	if (atomic_read(&ask->refcnt))
+		goto unlock;
 
 	swap(ask->type, type);
 	swap(ask->private, private);
 
+	err = 0;
+
+unlock:
 	release_sock(sk);
 
 	alg_do_release(type, private);
 
-	return 0;
+	return err;
 }
 
-static int alg_setkey(struct sock *sk, char __user *ukey,
-		      unsigned int keylen)
+static int alg_setkey(struct sock *sk, sockptr_t ukey, unsigned int keylen)
 {
 	struct alg_sock *ask = alg_sk(sk);
 	const struct af_alg_type *type = ask->type;
@@ -181,39 +217,188 @@ static int alg_setkey(struct sock *sk, char __user *ukey,
 		return -ENOMEM;
 
 	err = -EFAULT;
-	if (copy_from_user(key, ukey, keylen))
+	if (copy_from_sockptr(key, ukey, keylen))
 		goto out;
 
 	err = type->setkey(ask->private, key, keylen);
 
 out:
-	sock_kfree_s(sk, key, keylen);
+	sock_kzfree_s(sk, key, keylen);
+
+	return err;
+}
+
+#ifdef CONFIG_KEYS
+
+static const u8 *key_data_ptr_user(const struct key *key,
+				   unsigned int *datalen)
+{
+	const struct user_key_payload *ukp;
+
+	ukp = user_key_payload_locked(key);
+	if (IS_ERR_OR_NULL(ukp))
+		return ERR_PTR(-EKEYREVOKED);
+
+	*datalen = key->datalen;
+
+	return ukp->data;
+}
+
+static const u8 *key_data_ptr_encrypted(const struct key *key,
+					unsigned int *datalen)
+{
+	const struct encrypted_key_payload *ekp;
+
+	ekp = dereference_key_locked(key);
+	if (IS_ERR_OR_NULL(ekp))
+		return ERR_PTR(-EKEYREVOKED);
+
+	*datalen = ekp->decrypted_datalen;
+
+	return ekp->decrypted_data;
+}
+
+static const u8 *key_data_ptr_trusted(const struct key *key,
+				      unsigned int *datalen)
+{
+	const struct trusted_key_payload *tkp;
+
+	tkp = dereference_key_locked(key);
+	if (IS_ERR_OR_NULL(tkp))
+		return ERR_PTR(-EKEYREVOKED);
+
+	*datalen = tkp->key_len;
+
+	return tkp->key;
+}
+
+static struct key *lookup_key(key_serial_t serial)
+{
+	key_ref_t key_ref;
+
+	key_ref = lookup_user_key(serial, 0, KEY_NEED_SEARCH);
+	if (IS_ERR(key_ref))
+		return ERR_CAST(key_ref);
+
+	return key_ref_to_ptr(key_ref);
+}
+
+static int alg_setkey_by_key_serial(struct alg_sock *ask, sockptr_t optval,
+				    unsigned int optlen)
+{
+	const struct af_alg_type *type = ask->type;
+	u8 *key_data = NULL;
+	unsigned int key_datalen;
+	key_serial_t serial;
+	struct key *key;
+	const u8 *ret;
+	int err;
+
+	if (optlen != sizeof(serial))
+		return -EINVAL;
+
+	if (copy_from_sockptr(&serial, optval, optlen))
+		return -EFAULT;
+
+	key = lookup_key(serial);
+	if (IS_ERR(key))
+		return PTR_ERR(key);
+
+	down_read(&key->sem);
+
+	ret = ERR_PTR(-ENOPROTOOPT);
+	if (!strcmp(key->type->name, "user") ||
+	    !strcmp(key->type->name, "logon")) {
+		ret = key_data_ptr_user(key, &key_datalen);
+	} else if (IS_REACHABLE(CONFIG_ENCRYPTED_KEYS) &&
+			   !strcmp(key->type->name, "encrypted")) {
+		ret = key_data_ptr_encrypted(key, &key_datalen);
+	} else if (IS_REACHABLE(CONFIG_TRUSTED_KEYS) &&
+			   !strcmp(key->type->name, "trusted")) {
+		ret = key_data_ptr_trusted(key, &key_datalen);
+	}
+
+	if (IS_ERR(ret)) {
+		up_read(&key->sem);
+		key_put(key);
+		return PTR_ERR(ret);
+	}
+
+	key_data = sock_kmalloc(&ask->sk, key_datalen, GFP_KERNEL);
+	if (!key_data) {
+		up_read(&key->sem);
+		key_put(key);
+		return -ENOMEM;
+	}
+
+	memcpy(key_data, ret, key_datalen);
+
+	up_read(&key->sem);
+	key_put(key);
+
+	err = type->setkey(ask->private, key_data, key_datalen);
+
+	sock_kzfree_s(&ask->sk, key_data, key_datalen);
 
 	return err;
 }
 
+#else
+
+static inline int alg_setkey_by_key_serial(struct alg_sock *ask,
+					   sockptr_t optval,
+					   unsigned int optlen)
+{
+	return -ENOPROTOOPT;
+}
+
+#endif
+
 static int alg_setsockopt(struct socket *sock, int level, int optname,
-			  char __user *optval, unsigned int optlen)
+			  sockptr_t optval, unsigned int optlen)
 {
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
 	const struct af_alg_type *type;
-	int err = -ENOPROTOOPT;
+	int err = -EBUSY;
 
 	lock_sock(sk);
+	if (atomic_read(&ask->refcnt) != atomic_read(&ask->nokey_refcnt))
+		goto unlock;
+
 	type = ask->type;
 
+	err = -ENOPROTOOPT;
 	if (level != SOL_ALG || !type)
 		goto unlock;
 
 	switch (optname) {
 	case ALG_SET_KEY:
+	case ALG_SET_KEY_BY_KEY_SERIAL:
 		if (sock->state == SS_CONNECTED)
 			goto unlock;
 		if (!type->setkey)
 			goto unlock;
 
-		err = alg_setkey(sk, optval, optlen);
+		if (optname == ALG_SET_KEY_BY_KEY_SERIAL)
+			err = alg_setkey_by_key_serial(ask, optval, optlen);
+		else
+			err = alg_setkey(sk, optval, optlen);
+		break;
+	case ALG_SET_AEAD_AUTHSIZE:
+		if (sock->state == SS_CONNECTED)
+			goto unlock;
+		if (!type->setauthsize)
+			goto unlock;
+		err = type->setauthsize(ask->private, optlen);
+		break;
+	case ALG_SET_DRBG_ENTROPY:
+		if (sock->state == SS_CONNECTED)
+			goto unlock;
+		if (!type->setentropy)
+			goto unlock;
+
+		err = type->setentropy(ask->private, optval, optlen);
 	}
 
 unlock:
@@ -222,11 +407,13 @@ unlock:
 	return err;
 }
 
-int af_alg_accept(struct sock *sk, struct socket *newsock)
+int af_alg_accept(struct sock *sk, struct socket *newsock,
+		  struct proto_accept_arg *arg)
 {
 	struct alg_sock *ask = alg_sk(sk);
 	const struct af_alg_type *type;
 	struct sock *sk2;
+	unsigned int nokey;
 	int err;
 
 	lock_sock(sk);
@@ -236,29 +423,43 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
 	if (!type)
 		goto unlock;
 
-	sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto);
+	sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, arg->kern);
 	err = -ENOMEM;
 	if (!sk2)
 		goto unlock;
 
 	sock_init_data(newsock, sk2);
-	sock_graft(sk2, newsock);
+	security_sock_graft(sk2, newsock);
+	security_sk_clone(sk, sk2);
 
+	/*
+	 * newsock->ops assigned here to allow type->accept call to override
+	 * them when required.
+	 */
+	newsock->ops = type->ops;
 	err = type->accept(ask->private, sk2);
-	if (err) {
-		sk_free(sk2);
-		goto unlock;
-	}
 
-	sk2->sk_family = PF_ALG;
+	nokey = err == -ENOKEY;
+	if (nokey && type->accept_nokey)
+		err = type->accept_nokey(ask->private, sk2);
 
-	sock_hold(sk);
+	if (err)
+		goto unlock;
+
+	if (atomic_inc_return_relaxed(&ask->refcnt) == 1)
+		sock_hold(sk);
+	if (nokey) {
+		atomic_inc(&ask->nokey_refcnt);
+		atomic_set(&alg_sk(sk2)->nokey_refcnt, 1);
+	}
 	alg_sk(sk2)->parent = sk;
 	alg_sk(sk2)->type = type;
 
-	newsock->ops = type->ops;
 	newsock->state = SS_CONNECTED;
 
+	if (nokey)
+		newsock->ops = type->ops_nokey;
+
 	err = 0;
 
 unlock:
@@ -268,9 +469,10 @@ unlock:
 }
 EXPORT_SYMBOL_GPL(af_alg_accept);
 
-static int alg_accept(struct socket *sock, struct socket *newsock, int flags)
+static int alg_accept(struct socket *sock, struct socket *newsock,
+		      struct proto_accept_arg *arg)
 {
-	return af_alg_accept(sock->sk, newsock);
+	return af_alg_accept(sock->sk, newsock, arg);
 }
 
 static const struct proto_ops alg_proto_ops = {
@@ -283,12 +485,9 @@ static const struct proto_ops alg_proto_ops = {
 	.ioctl		=	sock_no_ioctl,
 	.listen		=	sock_no_listen,
 	.shutdown	=	sock_no_shutdown,
-	.getsockopt	=	sock_no_getsockopt,
 	.mmap		=	sock_no_mmap,
-	.sendpage	=	sock_no_sendpage,
 	.sendmsg	=	sock_no_sendmsg,
 	.recvmsg	=	sock_no_recvmsg,
-	.poll		=	sock_no_poll,
 
 	.bind		=	alg_bind,
 	.release	=	af_alg_release,
@@ -315,14 +514,13 @@ static int alg_create(struct net *net, struct socket *sock, int protocol,
 		return -EPROTONOSUPPORT;
 
 	err = -ENOMEM;
-	sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto);
+	sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
 	if (!sk)
 		goto out;
 
 	sock->ops = &alg_proto_ops;
 	sock_init_data(sock, sk);
 
-	sk->sk_family = PF_ALG;
 	sk->sk_destruct = alg_sock_destruct;
 
 	return 0;
@@ -336,74 +534,39 @@ static const struct net_proto_family alg_family = {
 	.owner	=	THIS_MODULE,
 };
 
-int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len,
-		   int write)
+static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
+			   struct af_alg_sgl *sgl_new)
 {
-	unsigned long from = (unsigned long)addr;
-	unsigned long npages;
-	unsigned off;
-	int err;
-	int i;
-
-	err = -EFAULT;
-	if (!access_ok(write ? VERIFY_READ : VERIFY_WRITE, addr, len))
-		goto out;
-
-	off = from & ~PAGE_MASK;
-	npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	if (npages > ALG_MAX_PAGES)
-		npages = ALG_MAX_PAGES;
-
-	err = get_user_pages_fast(from, npages, write, sgl->pages);
-	if (err < 0)
-		goto out;
-
-	npages = err;
-	err = -EINVAL;
-	if (WARN_ON(npages == 0))
-		goto out;
-
-	err = 0;
-
-	sg_init_table(sgl->sg, npages);
-
-	for (i = 0; i < npages; i++) {
-		int plen = min_t(int, len, PAGE_SIZE - off);
-
-		sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
-
-		off = 0;
-		len -= plen;
-		err += plen;
-	}
-
-out:
-	return err;
+	sg_unmark_end(sgl_prev->sgt.sgl + sgl_prev->sgt.nents - 1);
+	sg_chain(sgl_prev->sgt.sgl, sgl_prev->sgt.nents + 1, sgl_new->sgt.sgl);
 }
-EXPORT_SYMBOL_GPL(af_alg_make_sg);
 
 void af_alg_free_sg(struct af_alg_sgl *sgl)
 {
 	int i;
 
-	i = 0;
-	do {
-		put_page(sgl->pages[i]);
-	} while (!sg_is_last(sgl->sg + (i++)));
+	if (sgl->sgt.sgl) {
+		if (sgl->need_unpin)
+			for (i = 0; i < sgl->sgt.nents; i++)
+				unpin_user_page(sg_page(&sgl->sgt.sgl[i]));
+		if (sgl->sgt.sgl != sgl->sgl)
+			kvfree(sgl->sgt.sgl);
+		sgl->sgt.sgl = NULL;
+	}
 }
 EXPORT_SYMBOL_GPL(af_alg_free_sg);
 
-int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
+static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
 {
 	struct cmsghdr *cmsg;
 
-	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+	for_each_cmsghdr(cmsg, msg) {
 		if (!CMSG_OK(msg, cmsg))
 			return -EINVAL;
 		if (cmsg->cmsg_level != SOL_ALG)
 			continue;
 
-		switch(cmsg->cmsg_type) {
+		switch (cmsg->cmsg_type) {
 		case ALG_SET_IV:
 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
 				return -EINVAL;
@@ -419,6 +582,12 @@ int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
 			con->op = *(u32 *)CMSG_DATA(cmsg);
 			break;
 
+		case ALG_SET_AEAD_ASSOCLEN:
+			if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
+				return -EINVAL;
+			con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
+			break;
+
 		default:
 			return -EINVAL;
 		}
@@ -426,31 +595,707 @@ int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
 
-int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
+/**
+ * af_alg_alloc_tsgl - allocate the TX SGL
+ *
+ * @sk: socket of connection to user space
+ * Return: 0 upon success, < 0 upon error
+ */
+static int af_alg_alloc_tsgl(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_tsgl *sgl;
+	struct scatterlist *sg = NULL;
+
+	sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
+	if (!list_empty(&ctx->tsgl_list))
+		sg = sgl->sg;
+
+	if (!sg || sgl->cur >= MAX_SGL_ENTS) {
+		sgl = sock_kmalloc(sk,
+				   struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
+				   GFP_KERNEL);
+		if (!sgl)
+			return -ENOMEM;
+
+		sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
+		sgl->cur = 0;
+
+		if (sg)
+			sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
+
+		list_add_tail(&sgl->list, &ctx->tsgl_list);
+	}
+
+	return 0;
+}
+
+/**
+ * af_alg_count_tsgl - Count number of TX SG entries
+ *
+ * The counting starts from the beginning of the SGL to @bytes. If
+ * an @offset is provided, the counting of the SG entries starts at the @offset.
+ *
+ * @sk: socket of connection to user space
+ * @bytes: Count the number of SG entries holding given number of bytes.
+ * @offset: Start the counting of SG entries from the given offset.
+ * Return: Number of TX SG entries found given the constraints
+ */
+unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
 {
-	switch (err) {
-	case -EINPROGRESS:
-	case -EBUSY:
-		wait_for_completion(&completion->completion);
-		INIT_COMPLETION(completion->completion);
-		err = completion->err;
-		break;
-	};
+	const struct alg_sock *ask = alg_sk(sk);
+	const struct af_alg_ctx *ctx = ask->private;
+	const struct af_alg_tsgl *sgl;
+	unsigned int i;
+	unsigned int sgl_count = 0;
+
+	if (!bytes)
+		return 0;
+
+	list_for_each_entry(sgl, &ctx->tsgl_list, list) {
+		const struct scatterlist *sg = sgl->sg;
+
+		for (i = 0; i < sgl->cur; i++) {
+			size_t bytes_count;
+
+			/* Skip offset */
+			if (offset >= sg[i].length) {
+				offset -= sg[i].length;
+				bytes -= sg[i].length;
+				continue;
+			}
+
+			bytes_count = sg[i].length - offset;
+
+			offset = 0;
+			sgl_count++;
+
+			/* If we have seen requested number of bytes, stop */
+			if (bytes_count >= bytes)
+				return sgl_count;
+
+			bytes -= bytes_count;
+		}
+	}
+
+	return sgl_count;
+}
+EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
+
+/**
+ * af_alg_pull_tsgl - Release the specified buffers from TX SGL
+ *
+ * If @dst is non-null, reassign the pages to @dst. The caller must release
+ * the pages. If @dst_offset is given only reassign the pages to @dst starting
+ * at the @dst_offset (byte). The caller must ensure that @dst is large
+ * enough (e.g. by using af_alg_count_tsgl with the same offset).
+ *
+ * @sk: socket of connection to user space
+ * @used: Number of bytes to pull from TX SGL
+ * @dst: If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
+ *	 caller must release the buffers in dst.
+ * @dst_offset: Reassign the TX SGL from given offset. All buffers before
+ *	        reaching the offset is released.
+ */
+void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
+		      size_t dst_offset)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_tsgl *sgl;
+	struct scatterlist *sg;
+	unsigned int i, j = 0;
+
+	while (!list_empty(&ctx->tsgl_list)) {
+		sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
+				       list);
+		sg = sgl->sg;
+
+		for (i = 0; i < sgl->cur; i++) {
+			size_t plen = min_t(size_t, used, sg[i].length);
+			struct page *page = sg_page(sg + i);
+
+			if (!page)
+				continue;
+
+			/*
+			 * Assumption: caller created af_alg_count_tsgl(len)
+			 * SG entries in dst.
+			 */
+			if (dst) {
+				if (dst_offset >= plen) {
+					/* discard page before offset */
+					dst_offset -= plen;
+				} else {
+					/* reassign page to dst after offset */
+					get_page(page);
+					sg_set_page(dst + j, page,
+						    plen - dst_offset,
+						    sg[i].offset + dst_offset);
+					dst_offset = 0;
+					j++;
+				}
+			}
+
+			sg[i].length -= plen;
+			sg[i].offset += plen;
+
+			used -= plen;
+			ctx->used -= plen;
+
+			if (sg[i].length)
+				return;
+
+			put_page(page);
+			sg_assign_page(sg + i, NULL);
+		}
+
+		list_del(&sgl->list);
+		sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
+	}
+
+	if (!ctx->used)
+		ctx->merge = 0;
+	ctx->init = ctx->more;
+}
+EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
+
+/**
+ * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
+ *
+ * @areq: Request holding the TX and RX SGL
+ */
+static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
+{
+	struct sock *sk = areq->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_rsgl *rsgl, *tmp;
+	struct scatterlist *tsgl;
+	struct scatterlist *sg;
+	unsigned int i;
+
+	list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
+		atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
+		af_alg_free_sg(&rsgl->sgl);
+		list_del(&rsgl->list);
+		if (rsgl != &areq->first_rsgl)
+			sock_kfree_s(sk, rsgl, sizeof(*rsgl));
+	}
+
+	tsgl = areq->tsgl;
+	if (tsgl) {
+		for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
+			if (!sg_page(sg))
+				continue;
+			put_page(sg_page(sg));
+		}
+
+		sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
+	}
+}
+
+/**
+ * af_alg_wait_for_wmem - wait for availability of writable memory
+ *
+ * @sk: socket of connection to user space
+ * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
+ * Return: 0 when writable memory is available, < 0 upon error
+ */
+static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	int err = -ERESTARTSYS;
+	long timeout;
+
+	if (flags & MSG_DONTWAIT)
+		return -EAGAIN;
+
+	sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	for (;;) {
+		if (signal_pending(current))
+			break;
+		timeout = MAX_SCHEDULE_TIMEOUT;
+		if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
+			err = 0;
+			break;
+		}
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+
+	return err;
+}
+
+/**
+ * af_alg_wmem_wakeup - wakeup caller when writable memory is available
+ *
+ * @sk: socket of connection to user space
+ */
+void af_alg_wmem_wakeup(struct sock *sk)
+{
+	struct socket_wq *wq;
+
+	if (!af_alg_writable(sk))
+		return;
+
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (skwq_has_sleeper(wq))
+		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
+							   EPOLLRDNORM |
+							   EPOLLRDBAND);
+	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
+
+/**
+ * af_alg_wait_for_data - wait for availability of TX data
+ *
+ * @sk: socket of connection to user space
+ * @flags: If MSG_DONTWAIT is set, then only report if function would sleep
+ * @min: Set to minimum request size if partial requests are allowed.
+ * Return: 0 when writable memory is available, < 0 upon error
+ */
+int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	long timeout;
+	int err = -ERESTARTSYS;
+
+	if (flags & MSG_DONTWAIT)
+		return -EAGAIN;
+
+	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	for (;;) {
+		if (signal_pending(current))
+			break;
+		timeout = MAX_SCHEDULE_TIMEOUT;
+		if (sk_wait_event(sk, &timeout,
+				  ctx->init && (!ctx->more ||
+						(min && ctx->used >= min)),
+				  &wait)) {
+			err = 0;
+			break;
+		}
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+
+	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 
 	return err;
 }
-EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
+EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
+
+/**
+ * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
+ *
+ * @sk: socket of connection to user space
+ */
+static void af_alg_data_wakeup(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct socket_wq *wq;
+
+	if (!ctx->used)
+		return;
+
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (skwq_has_sleeper(wq))
+		wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
+							   EPOLLRDNORM |
+							   EPOLLRDBAND);
+	sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
+	rcu_read_unlock();
+}
+
+/**
+ * af_alg_sendmsg - implementation of sendmsg system call handler
+ *
+ * The sendmsg system call handler obtains the user data and stores it
+ * in ctx->tsgl_list. This implies allocation of the required numbers of
+ * struct af_alg_tsgl.
+ *
+ * In addition, the ctx is filled with the information sent via CMSG.
+ *
+ * @sock: socket of connection to user space
+ * @msg: message from user space
+ * @size: size of message from user space
+ * @ivsize: the size of the IV for the cipher operation to verify that the
+ *	   user-space-provided IV has the right size
+ * Return: the number of copied data upon success, < 0 upon error
+ */
+int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
+		   unsigned int ivsize)
+{
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct af_alg_tsgl *sgl;
+	struct af_alg_control con = {};
+	long copied = 0;
+	bool enc = false;
+	bool init = false;
+	int err = 0;
+
+	if (msg->msg_controllen) {
+		err = af_alg_cmsg_send(msg, &con);
+		if (err)
+			return err;
+
+		init = true;
+		switch (con.op) {
+		case ALG_OP_ENCRYPT:
+			enc = true;
+			break;
+		case ALG_OP_DECRYPT:
+			enc = false;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		if (con.iv && con.iv->ivlen != ivsize)
+			return -EINVAL;
+	}
+
+	lock_sock(sk);
+	if (ctx->write) {
+		release_sock(sk);
+		return -EBUSY;
+	}
+	ctx->write = true;
+
+	if (ctx->init && !ctx->more) {
+		if (ctx->used) {
+			err = -EINVAL;
+			goto unlock;
+		}
+
+		pr_info_once(
+			"%s sent an empty control message without MSG_MORE.\n",
+			current->comm);
+	}
+	ctx->init = true;
+
+	if (init) {
+		ctx->enc = enc;
+		if (con.iv)
+			memcpy(ctx->iv, con.iv->iv, ivsize);
+
+		ctx->aead_assoclen = con.aead_assoclen;
+	}
+
+	while (size) {
+		struct scatterlist *sg;
+		size_t len = size;
+		ssize_t plen;
+
+		/* use the existing memory in an allocated page */
+		if (ctx->merge && !(msg->msg_flags & MSG_SPLICE_PAGES)) {
+			sgl = list_entry(ctx->tsgl_list.prev,
+					 struct af_alg_tsgl, list);
+			sg = sgl->sg + sgl->cur - 1;
+			len = min_t(size_t, len,
+				    PAGE_SIZE - sg->offset - sg->length);
+
+			err = memcpy_from_msg(page_address(sg_page(sg)) +
+					      sg->offset + sg->length,
+					      msg, len);
+			if (err)
+				goto unlock;
+
+			sg->length += len;
+			ctx->merge = (sg->offset + sg->length) &
+				     (PAGE_SIZE - 1);
+
+			ctx->used += len;
+			copied += len;
+			size -= len;
+			continue;
+		}
+
+		ctx->merge = 0;
+
+		if (!af_alg_writable(sk)) {
+			err = af_alg_wait_for_wmem(sk, msg->msg_flags);
+			if (err)
+				goto unlock;
+		}
+
+		/* allocate a new page */
+		len = min_t(unsigned long, len, af_alg_sndbuf(sk));
+
+		err = af_alg_alloc_tsgl(sk);
+		if (err)
+			goto unlock;
+
+		sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
+				 list);
+		sg = sgl->sg;
+		if (sgl->cur)
+			sg_unmark_end(sg + sgl->cur - 1);
+
+		if (msg->msg_flags & MSG_SPLICE_PAGES) {
+			struct sg_table sgtable = {
+				.sgl		= sg,
+				.nents		= sgl->cur,
+				.orig_nents	= sgl->cur,
+			};
+
+			plen = extract_iter_to_sg(&msg->msg_iter, len, &sgtable,
+						  MAX_SGL_ENTS - sgl->cur, 0);
+			if (plen < 0) {
+				err = plen;
+				goto unlock;
+			}
+
+			for (; sgl->cur < sgtable.nents; sgl->cur++)
+				get_page(sg_page(&sg[sgl->cur]));
+			len -= plen;
+			ctx->used += plen;
+			copied += plen;
+			size -= plen;
+		} else {
+			do {
+				struct page *pg;
+				unsigned int i = sgl->cur;
+
+				plen = min_t(size_t, len, PAGE_SIZE);
+
+				pg = alloc_page(GFP_KERNEL);
+				if (!pg) {
+					err = -ENOMEM;
+					goto unlock;
+				}
+
+				sg_assign_page(sg + i, pg);
+
+				err = memcpy_from_msg(
+					page_address(sg_page(sg + i)),
+					msg, plen);
+				if (err) {
+					__free_page(sg_page(sg + i));
+					sg_assign_page(sg + i, NULL);
+					goto unlock;
+				}
+
+				sg[i].length = plen;
+				len -= plen;
+				ctx->used += plen;
+				copied += plen;
+				size -= plen;
+				sgl->cur++;
+			} while (len && sgl->cur < MAX_SGL_ENTS);
+
+			ctx->merge = plen & (PAGE_SIZE - 1);
+		}
+
+		if (!size)
+			sg_mark_end(sg + sgl->cur - 1);
+	}
+
+	err = 0;
+
+	ctx->more = msg->msg_flags & MSG_MORE;
+
+unlock:
+	af_alg_data_wakeup(sk);
+	ctx->write = false;
+	release_sock(sk);
+
+	return copied ?: err;
+}
+EXPORT_SYMBOL_GPL(af_alg_sendmsg);
+
+/**
+ * af_alg_free_resources - release resources required for crypto request
+ * @areq: Request holding the TX and RX SGL
+ */
+void af_alg_free_resources(struct af_alg_async_req *areq)
+{
+	struct sock *sk = areq->sk;
+	struct af_alg_ctx *ctx;
+
+	af_alg_free_areq_sgls(areq);
+	sock_kfree_s(sk, areq, areq->areqlen);
+
+	ctx = alg_sk(sk)->private;
+	ctx->inflight = false;
+}
+EXPORT_SYMBOL_GPL(af_alg_free_resources);
+
+/**
+ * af_alg_async_cb - AIO callback handler
+ * @data: async request completion data
+ * @err: if non-zero, error result to be returned via ki_complete();
+ *       otherwise return the AIO output length via ki_complete().
+ *
+ * This handler cleans up the struct af_alg_async_req upon completion of the
+ * AIO operation.
+ *
+ * The number of bytes to be generated with the AIO operation must be set
+ * in areq->outlen before the AIO callback handler is invoked.
+ */
+void af_alg_async_cb(void *data, int err)
+{
+	struct af_alg_async_req *areq = data;
+	struct sock *sk = areq->sk;
+	struct kiocb *iocb = areq->iocb;
+	unsigned int resultlen;
+
+	/* Buffer size written by crypto operation. */
+	resultlen = areq->outlen;
+
+	af_alg_free_resources(areq);
+	sock_put(sk);
+
+	iocb->ki_complete(iocb, err ? err : (int)resultlen);
+}
+EXPORT_SYMBOL_GPL(af_alg_async_cb);
+
+/**
+ * af_alg_poll - poll system call handler
+ * @file: file pointer
+ * @sock: socket to poll
+ * @wait: poll_table
+ */
+__poll_t af_alg_poll(struct file *file, struct socket *sock,
+			 poll_table *wait)
+{
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	__poll_t mask;
+
+	sock_poll_wait(file, sock, wait);
+	mask = 0;
+
+	if (!ctx->more || ctx->used)
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	if (af_alg_writable(sk))
+		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
+
+	return mask;
+}
+EXPORT_SYMBOL_GPL(af_alg_poll);
 
-void af_alg_complete(struct crypto_async_request *req, int err)
+/**
+ * af_alg_alloc_areq - allocate struct af_alg_async_req
+ *
+ * @sk: socket of connection to user space
+ * @areqlen: size of struct af_alg_async_req + crypto_*_reqsize
+ * Return: allocated data structure or ERR_PTR upon error
+ */
+struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
+					   unsigned int areqlen)
 {
-	struct af_alg_completion *completion = req->data;
+	struct af_alg_ctx *ctx = alg_sk(sk)->private;
+	struct af_alg_async_req *areq;
+
+	/* Only one AIO request can be in flight. */
+	if (ctx->inflight)
+		return ERR_PTR(-EBUSY);
 
-	completion->err = err;
-	complete(&completion->completion);
+	areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
+	if (unlikely(!areq))
+		return ERR_PTR(-ENOMEM);
+
+	memset(areq, 0, areqlen);
+
+	ctx->inflight = true;
+
+	areq->areqlen = areqlen;
+	areq->sk = sk;
+	areq->first_rsgl.sgl.sgt.sgl = areq->first_rsgl.sgl.sgl;
+	INIT_LIST_HEAD(&areq->rsgl_list);
+
+	return areq;
+}
+EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
+
+/**
+ * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
+ *		     operation
+ *
+ * @sk: socket of connection to user space
+ * @msg: user space message
+ * @flags: flags used to invoke recvmsg with
+ * @areq: instance of the cryptographic request that will hold the RX SGL
+ * @maxsize: maximum number of bytes to be pulled from user space
+ * @outlen: number of bytes in the RX SGL
+ * Return: 0 on success, < 0 upon error
+ */
+int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
+		    struct af_alg_async_req *areq, size_t maxsize,
+		    size_t *outlen)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	size_t len = 0;
+
+	while (maxsize > len && msg_data_left(msg)) {
+		struct af_alg_rsgl *rsgl;
+		ssize_t err;
+		size_t seglen;
+
+		/* limit the amount of readable buffers */
+		if (!af_alg_readable(sk))
+			break;
+
+		seglen = min_t(size_t, (maxsize - len),
+			       msg_data_left(msg));
+
+		if (list_empty(&areq->rsgl_list)) {
+			rsgl = &areq->first_rsgl;
+		} else {
+			rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
+			if (unlikely(!rsgl))
+				return -ENOMEM;
+		}
+
+		rsgl->sgl.need_unpin =
+			iov_iter_extract_will_pin(&msg->msg_iter);
+		rsgl->sgl.sgt.sgl = rsgl->sgl.sgl;
+		rsgl->sgl.sgt.nents = 0;
+		rsgl->sgl.sgt.orig_nents = 0;
+		list_add_tail(&rsgl->list, &areq->rsgl_list);
+
+		sg_init_table(rsgl->sgl.sgt.sgl, ALG_MAX_PAGES);
+		err = extract_iter_to_sg(&msg->msg_iter, seglen, &rsgl->sgl.sgt,
+					 ALG_MAX_PAGES, 0);
+		if (err < 0) {
+			rsgl->sg_num_bytes = 0;
+			return err;
+		}
+
+		sg_mark_end(rsgl->sgl.sgt.sgl + rsgl->sgl.sgt.nents - 1);
+
+		/* chain the new scatterlist with previous one */
+		if (areq->last_rsgl)
+			af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
+
+		areq->last_rsgl = rsgl;
+		len += err;
+		atomic_add(err, &ctx->rcvused);
+		rsgl->sg_num_bytes = err;
+	}
+
+	*outlen = len;
+	return 0;
 }
-EXPORT_SYMBOL_GPL(af_alg_complete);
+EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
 
 static int __init af_alg_init(void)
 {
@@ -479,5 +1324,6 @@ static void __exit af_alg_exit(void)
 
 module_init(af_alg_init);
 module_exit(af_alg_exit);
+MODULE_DESCRIPTION("Crypto userspace interface");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_NETPROTO(AF_ALG);