AF_ALG fixes

index 16f6ba896fb6..9f0b27005166 100644
@@ -67,10 +67,104 @@ void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
 	scatterwalk_copychunks(buf, &walk, nbytes, out);
 	scatterwalk_done(&walk, out, 0);
 }
 EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
 
+/**
+ * memcpy_sglist() - Copy data from one scatterlist to another
+ * @dst: The destination scatterlist.  Can be NULL if @nbytes == 0.
+ * @src: The source scatterlist.  Can be NULL if @nbytes == 0.
+ * @nbytes: Number of bytes to copy
+ *
+ * The scatterlists can describe exactly the same memory, in which case this
+ * function is a no-op.  No other overlaps are supported.
+ *
+ * Context: Any context
+ */
+void memcpy_sglist(struct scatterlist *dst, struct scatterlist *src,
+		   unsigned int nbytes)
+{
+	unsigned int src_offset, dst_offset;
+
+	if (unlikely(nbytes == 0)) /* in case src and/or dst is NULL */
+		return;
+
+	src_offset = src->offset;
+	dst_offset = dst->offset;
+	for (;;) {
+		/* Compute the length to copy this step. */
+		unsigned int len = min3(src->offset + src->length - src_offset,
+					dst->offset + dst->length - dst_offset,
+					nbytes);
+		struct page *src_page = sg_page(src);
+		struct page *dst_page = sg_page(dst);
+		const void *src_virt;
+		void *dst_virt;
+
+		if (IS_ENABLED(CONFIG_HIGHMEM)) {
+			/* HIGHMEM: we may have to actually map the pages. */
+			const unsigned int src_oip = offset_in_page(src_offset);
+			const unsigned int dst_oip = offset_in_page(dst_offset);
+			const unsigned int limit = PAGE_SIZE;
+
+			/* Further limit len to not cross a page boundary. */
+			len = min3(len, limit - src_oip, limit - dst_oip);
+
+			/* Compute the source and destination pages. */
+			src_page += src_offset / PAGE_SIZE;
+			dst_page += dst_offset / PAGE_SIZE;
+
+			if (src_page != dst_page) {
+				/* Copy between different pages. */
+				memcpy_page(dst_page, dst_oip,
+					    src_page, src_oip, len);
+				flush_dcache_page(dst_page);
+			} else if (src_oip != dst_oip) {
+				/* Copy between different parts of same page. */
+				dst_virt = kmap_local_page(dst_page);
+				memcpy(dst_virt + dst_oip, dst_virt + src_oip,
+				       len);
+				kunmap_local(dst_virt);
+				flush_dcache_page(dst_page);
+			} /* Else, it's the same memory.  No action needed. */
+		} else {
+			/*
+			 * !HIGHMEM: no mapping needed.  Just work in the linear
+			 * buffer of each sg entry.  Note that we can cross page
+			 * boundaries, as they are not significant in this case.
+			 */
+			src_virt = page_address(src_page) + src_offset;
+			dst_virt = page_address(dst_page) + dst_offset;
+			if (src_virt != dst_virt) {
+				memcpy(dst_virt, src_virt, len);
+				if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE)
+					__scatterwalk_flush_dcache_pages(
+						dst_page, dst_offset, len);
+			} /* Else, it's the same memory.  No action needed. */
+		}
+		nbytes -= len;
+		if (nbytes == 0) /* No more to copy? */
+			break;
+
+		/*
+		 * There's more to copy.  Advance the offsets by the length
+		 * copied this step, and advance the sg entries as needed.
+		 */
+		src_offset += len;
+		if (src_offset >= src->offset + src->length) {
+			src = sg_next(src);
+			src_offset = src->offset;
+		}
+		dst_offset += len;
+		if (dst_offset >= dst->offset + dst->length) {
+			dst = sg_next(dst);
+			dst_offset = dst->offset;
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(memcpy_sglist);
+
 struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
 				     struct scatterlist *src,
 				     unsigned int len)
 {
 	for (;;) {

index 32fc4473175b..7e7942950c07 100644
@@ -81,10 +81,38 @@ static inline void scatterwalk_pagedone(struct scatter_walk *walk, int out,
 
 	if (more && walk->offset >= walk->sg->offset + walk->sg->length)
 		scatterwalk_start(walk, sg_next(walk->sg));
 }
 
+/*
+ * Flush the dcache of any pages that overlap the region
+ * [offset, offset + nbytes) relative to base_page.
+ *
+ * This should be called only when ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, to ensure
+ * that all relevant code (including the call to sg_page() in the caller, if
+ * applicable) gets fully optimized out when !ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE.
+ */
+static inline void __scatterwalk_flush_dcache_pages(struct page *base_page,
+						    unsigned int offset,
+						    unsigned int nbytes)
+{
+	unsigned int num_pages;
+
+	base_page += offset / PAGE_SIZE;
+	offset %= PAGE_SIZE;
+
+	/*
+	 * This is an overflow-safe version of
+	 * num_pages = DIV_ROUND_UP(offset + nbytes, PAGE_SIZE).
+	 */
+	num_pages = nbytes / PAGE_SIZE;
+	num_pages += DIV_ROUND_UP(offset + (nbytes % PAGE_SIZE), PAGE_SIZE);
+
+	for (unsigned int i = 0; i < num_pages; i++)
+		flush_dcache_page(base_page + i);
+}
+
 static inline void scatterwalk_done(struct scatter_walk *walk, int out,
 				    int more)
 {
 	if (!more || walk->offset >= walk->sg->offset + walk->sg->length ||
 	    !(walk->offset & (PAGE_SIZE - 1)))

@@ -92,10 +120,13 @@ static inline void scatterwalk_done(struct scatter_walk *walk, int out,
 }
 
 void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
 			    size_t nbytes, int out);
 
+void memcpy_sglist(struct scatterlist *dst, struct scatterlist *src,
+		   unsigned int nbytes);
+
 void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
 			      unsigned int start, unsigned int nbytes, int out);
 
 struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
 				     struct scatterlist *src,

240 lines not on this page · raw message

index 0530dc85e4f8..6867d177f2a2 100644
@@ -635,19 +635,17 @@ static int af_alg_alloc_tsgl(struct sock *sk)
 }
 
 /**
  * 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.
+ * The counting starts from the beginning of the SGL to @bytes.
  *
  * @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)
+unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes)
 {
 	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;

@@ -658,29 +656,15 @@ unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
 
 	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)
+			if (sg[i].length >= bytes)
 				return sgl_count;
 
-			bytes -= bytes_count;
+			bytes -= sg[i].length;
 		}
 	}
 
 	return sgl_count;
 }

@@ -688,23 +672,18 @@ 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).
+ * the pages.
  *
  * @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)
+void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst)
 {
 	struct alg_sock *ask = alg_sk(sk);
 	struct af_alg_ctx *ctx = ask->private;
 	struct af_alg_tsgl *sgl;
 	struct scatterlist *sg;

@@ -725,22 +704,14 @@ void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
 			/*
 			 * 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++;
-				}
+				/* reassign page to dst after offset */
+				get_page(page);
+				sg_set_page(dst + j, page, plen, sg[i].offset);
+				j++;
 			}
 
 			sg[i].length -= plen;
 			sg[i].offset += plen;
 

159 lines not on this page · raw message

index 3549ad1cc42e..ba0a17fd95ac 100644
@@ -141,22 +141,22 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 
 	/*
 	 * Create a per request TX SGL for this request which tracks the
 	 * SG entries from the global TX SGL.
 	 */
-	areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0);
+	areq->tsgl_entries = af_alg_count_tsgl(sk, len);
 	if (!areq->tsgl_entries)
 		areq->tsgl_entries = 1;
 	areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
 						 areq->tsgl_entries),
 				  GFP_KERNEL);
 	if (!areq->tsgl) {
 		err = -ENOMEM;
 		goto free;
 	}
 	sg_init_table(areq->tsgl, areq->tsgl_entries);
-	af_alg_pull_tsgl(sk, len, areq->tsgl, 0);
+	af_alg_pull_tsgl(sk, len, areq->tsgl);
 
 	/* Initialize the crypto operation */
 	skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm);
 	skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl,
 				   areq->first_rsgl.sgl.sgt.sgl, len, ctx->iv);

@@ -366,11 +366,11 @@ static void skcipher_sock_destruct(struct sock *sk)
 	struct af_alg_ctx *ctx = ask->private;
 	struct sock *psk = ask->parent;
 	struct alg_sock *pask = alg_sk(psk);
 	struct crypto_skcipher *tfm = pask->private;
 
-	af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
+	af_alg_pull_tsgl(sk, ctx->used, NULL);
 	sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
 	if (ctx->state)
 		sock_kzfree_s(sk, ctx->state, crypto_skcipher_statesize(tfm));
 	sock_kfree_s(sk, ctx, ctx->len);
 	af_alg_release_parent(sk);

index 107b797c33ec..0cc8fa749f68 100644
@@ -228,13 +228,12 @@ static inline int af_alg_rcvbuf(struct sock *sk)
 static inline bool af_alg_readable(struct sock *sk)
 {
 	return PAGE_SIZE <= af_alg_rcvbuf(sk);
 }
 
-unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset);
-void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
-		      size_t dst_offset);
+unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes);
+void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst);
 void af_alg_wmem_wakeup(struct sock *sk);
 int af_alg_wait_for_data(struct sock *sk, unsigned flags, unsigned min);
 int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		   unsigned int ivsize);
 void af_alg_free_resources(struct af_alg_async_req *areq);

index f8bd45f7dc83..cb651ab58d62 100644
@@ -70,12 +70,14 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 	struct sock *psk = ask->parent;
 	struct alg_sock *pask = alg_sk(psk);
 	struct af_alg_ctx *ctx = ask->private;
 	struct crypto_aead *tfm = pask->private;
 	unsigned int as = crypto_aead_authsize(tfm);
+	unsigned int ivsize = crypto_aead_ivsize(tfm);
 	struct af_alg_async_req *areq;
 	struct scatterlist *rsgl_src, *tsgl_src = NULL;
+	void *iv;
 	int err = 0;
 	size_t used = 0;		/* [in]  TX bufs to be en/decrypted */
 	size_t outlen = 0;		/* [out] RX bufs produced by kernel */
 	size_t usedpages = 0;		/* [in]  RX bufs to be used from user */
 	size_t processed = 0;		/* [in]  TX bufs to be consumed */

@@ -123,14 +125,18 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 	 */
 	used -= ctx->aead_assoclen;
 
 	/* Allocate cipher request for current operation. */
 	areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
-				     crypto_aead_reqsize(tfm));
+				     crypto_aead_reqsize(tfm) + ivsize);
 	if (IS_ERR(areq))
 		return PTR_ERR(areq);
 
+	iv = (u8 *)aead_request_ctx(&areq->cra_u.aead_req) +
+	     crypto_aead_reqsize(tfm);
+	memcpy(iv, ctx->iv, ivsize);
+
 	/* convert iovecs of output buffers into RX SGL */
 	err = af_alg_get_rsgl(sk, msg, flags, areq, outlen, &usedpages);
 	if (err)
 		goto free;
 

@@ -185,11 +191,11 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 
 	memcpy_sglist(rsgl_src, tsgl_src, ctx->aead_assoclen);
 
 	/* Initialize the crypto operation */
 	aead_request_set_crypt(&areq->cra_u.aead_req, tsgl_src,
-			       areq->first_rsgl.sgl.sgt.sgl, used, ctx->iv);
+			       areq->first_rsgl.sgl.sgt.sgl, used, iv);
 	aead_request_set_ad(&areq->cra_u.aead_req, ctx->aead_assoclen);
 	aead_request_set_tfm(&areq->cra_u.aead_req, tfm);
 
 	if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
 		/* AIO operation */

index d04068af9833..f1f7886bb34c 100644
@@ -7,11 +7,10 @@
 
 #include <crypto/internal/aead.h>
 #include <crypto/internal/hash.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/authenc.h>
-#include <crypto/null.h>
 #include <crypto/scatterwalk.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>

@@ -26,11 +25,10 @@ struct authenc_instance_ctx {
 };
 
 struct crypto_authenc_ctx {
 	struct crypto_ahash *auth;
 	struct crypto_skcipher *enc;
-	struct crypto_sync_skcipher *null;
 };
 
 struct authenc_request_ctx {
 	struct scatterlist src[2];
 	struct scatterlist dst[2];

@@ -184,25 +182,10 @@ static void crypto_authenc_encrypt_done(void *data, int err)
 	}
 	err = crypto_authenc_genicv(areq, CRYPTO_TFM_REQ_MAY_SLEEP);
 	authenc_request_complete(areq, err);
 }
 
-static int crypto_authenc_copy_assoc(struct aead_request *req)
-{
-	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
-	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
-	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
-
-	skcipher_request_set_sync_tfm(skreq, ctx->null);
-	skcipher_request_set_callback(skreq, aead_request_flags(req),
-				      NULL, NULL);
-	skcipher_request_set_crypt(skreq, req->src, req->dst, req->assoclen,
-				   NULL);
-
-	return crypto_skcipher_encrypt(skreq);
-}
-
 static int crypto_authenc_encrypt(struct aead_request *req)
 {
 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 	struct aead_instance *inst = aead_alg_instance(authenc);
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);

@@ -217,14 +200,11 @@ static int crypto_authenc_encrypt(struct aead_request *req)
 
 	src = scatterwalk_ffwd(areq_ctx->src, req->src, req->assoclen);
 	dst = src;
 
 	if (req->src != req->dst) {
-		err = crypto_authenc_copy_assoc(req);
-		if (err)
-			return err;
-
+		memcpy_sglist(req->dst, req->src, req->assoclen);
 		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
 	}
 
 	skcipher_request_set_tfm(skreq, enc);
 	skcipher_request_set_callback(skreq, aead_request_flags(req),

@@ -326,11 +306,10 @@ static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
 	struct aead_instance *inst = aead_alg_instance(tfm);
 	struct authenc_instance_ctx *ictx = aead_instance_ctx(inst);
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
 	struct crypto_ahash *auth;
 	struct crypto_skcipher *enc;
-	struct crypto_sync_skcipher *null;
 	int err;
 
 	auth = crypto_spawn_ahash(&ictx->auth);
 	if (IS_ERR(auth))
 		return PTR_ERR(auth);

@@ -338,18 +317,12 @@ static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
 	enc = crypto_spawn_skcipher(&ictx->enc);
 	err = PTR_ERR(enc);
 	if (IS_ERR(enc))
 		goto err_free_ahash;
 
-	null = crypto_get_default_null_skcipher();
-	err = PTR_ERR(null);
-	if (IS_ERR(null))
-		goto err_free_skcipher;
-
 	ctx->auth = auth;
 	ctx->enc = enc;
-	ctx->null = null;
 
 	crypto_aead_set_reqsize(
 		tfm,
 		sizeof(struct authenc_request_ctx) +
 		ictx->reqoff +

@@ -359,12 +332,10 @@ static int crypto_authenc_init_tfm(struct crypto_aead *tfm)
 		      sizeof(struct skcipher_request) +
 		      crypto_skcipher_reqsize(enc)));
 
 	return 0;
 
-err_free_skcipher:
-	crypto_free_skcipher(enc);
 err_free_ahash:
 	crypto_free_ahash(auth);
 	return err;
 }
 

@@ -372,11 +343,10 @@ static void crypto_authenc_exit_tfm(struct crypto_aead *tfm)
 {
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(tfm);
 
 	crypto_free_ahash(ctx->auth);
 	crypto_free_skcipher(ctx->enc);
-	crypto_put_default_null_skcipher();
 }
 
 static void crypto_authenc_free(struct aead_instance *inst)
 {
 	struct authenc_instance_ctx *ctx = aead_instance_ctx(inst);

index e08032e80f18..a5fbb638d9d7 100644
@@ -10,11 +10,10 @@
 
 #include <crypto/internal/aead.h>
 #include <crypto/internal/hash.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/authenc.h>
-#include <crypto/null.h>
 #include <crypto/scatterwalk.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>

@@ -29,11 +28,10 @@ struct authenc_esn_instance_ctx {
 
 struct crypto_authenc_esn_ctx {
 	unsigned int reqoff;
 	struct crypto_ahash *auth;
 	struct crypto_skcipher *enc;
-	struct crypto_sync_skcipher *null;
 };
 
 struct authenc_esn_request_ctx {
 	struct scatterlist src[2];
 	struct scatterlist dst[2];

@@ -156,24 +154,10 @@ static void crypto_authenc_esn_encrypt_done(void *data, int err)
 		err = crypto_authenc_esn_genicv(areq, 0);
 
 	authenc_esn_request_complete(areq, err);
 }
 
-static int crypto_authenc_esn_copy(struct aead_request *req, unsigned int len)
-{
-	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
-	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);
-	SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null);
-
-	skcipher_request_set_sync_tfm(skreq, ctx->null);
-	skcipher_request_set_callback(skreq, aead_request_flags(req),
-				      NULL, NULL);
-	skcipher_request_set_crypt(skreq, req->src, req->dst, len, NULL);
-
-	return crypto_skcipher_encrypt(skreq);
-}
-
 static int crypto_authenc_esn_encrypt(struct aead_request *req)
 {
 	struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req);
 	struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req);
 	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn);

@@ -191,14 +175,11 @@ static int crypto_authenc_esn_encrypt(struct aead_request *req)
 	sg_init_table(areq_ctx->src, 2);
 	src = scatterwalk_ffwd(areq_ctx->src, req->src, assoclen);
 	dst = src;
 
 	if (req->src != req->dst) {
-		err = crypto_authenc_esn_copy(req, assoclen);
-		if (err)
-			return err;
-
+		memcpy_sglist(req->dst, req->src, assoclen);
 		sg_init_table(areq_ctx->dst, 2);
 		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, assoclen);
 	}
 
 	skcipher_request_set_tfm(skreq, enc);

@@ -281,15 +262,12 @@ static int crypto_authenc_esn_decrypt(struct aead_request *req)
 	if (assoclen < 8)
 		return -EINVAL;
 
 	cryptlen -= authsize;
 
-	if (req->src != dst) {
-		err = crypto_authenc_esn_copy(req, assoclen + cryptlen);
-		if (err)
-			return err;
-	}
+	if (req->src != dst)
+		memcpy_sglist(dst, req->src, assoclen + cryptlen);
 
 	scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen,
 				 authsize, 0);
 
 	if (!authsize)

@@ -321,11 +299,10 @@ static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
 	struct aead_instance *inst = aead_alg_instance(tfm);
 	struct authenc_esn_instance_ctx *ictx = aead_instance_ctx(inst);
 	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
 	struct crypto_ahash *auth;
 	struct crypto_skcipher *enc;
-	struct crypto_sync_skcipher *null;
 	int err;
 
 	auth = crypto_spawn_ahash(&ictx->auth);
 	if (IS_ERR(auth))
 		return PTR_ERR(auth);

@@ -333,18 +310,12 @@ static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
 	enc = crypto_spawn_skcipher(&ictx->enc);
 	err = PTR_ERR(enc);
 	if (IS_ERR(enc))
 		goto err_free_ahash;
 
-	null = crypto_get_default_null_skcipher();
-	err = PTR_ERR(null);
-	if (IS_ERR(null))
-		goto err_free_skcipher;
-
 	ctx->auth = auth;
 	ctx->enc = enc;
-	ctx->null = null;
 
 	ctx->reqoff = 2 * crypto_ahash_digestsize(auth);
 
 	crypto_aead_set_reqsize(
 		tfm,

@@ -356,12 +327,10 @@ static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
 		      sizeof(struct skcipher_request) +
 		      crypto_skcipher_reqsize(enc)));
 
 	return 0;
 
-err_free_skcipher:
-	crypto_free_skcipher(enc);
 err_free_ahash:
 	crypto_free_ahash(auth);
 	return err;
 }
 

@@ -369,11 +338,10 @@ static void crypto_authenc_esn_exit_tfm(struct crypto_aead *tfm)
 {
 	struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm);
 
 	crypto_free_ahash(ctx->auth);
 	crypto_free_skcipher(ctx->enc);
-	crypto_put_default_null_skcipher();
 }
 
 static void crypto_authenc_esn_free(struct aead_instance *inst)
 {
 	struct authenc_esn_instance_ctx *ctx = aead_instance_ctx(inst);

index a5fbb638d9d7..257af38ac4de 100644
@@ -205,34 +205,39 @@ static int crypto_authenc_esn_decrypt_tail(struct aead_request *req,
 						  ctx->reqoff);
 	struct crypto_ahash *auth = ctx->auth;
 	u8 *ohash = areq_ctx->tail;
 	unsigned int cryptlen = req->cryptlen - authsize;
 	unsigned int assoclen = req->assoclen;
+	struct scatterlist *src = req->src;
 	struct scatterlist *dst = req->dst;
 	u8 *ihash = ohash + crypto_ahash_digestsize(auth);
 	u32 tmp[2];
 
 	if (!authsize)
 		goto decrypt;
 
-	/* Move high-order bits of sequence number back. */
-	scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
-	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
-	scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
+	if (src == dst) {
+		/* Move high-order bits of sequence number back. */
+		scatterwalk_map_and_copy(tmp, dst, 4, 4, 0);
+		scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0);
+		scatterwalk_map_and_copy(tmp, dst, 0, 8, 1);
+	} else
+		memcpy_sglist(dst, src, assoclen);
 
 	if (crypto_memneq(ihash, ohash, authsize))
 		return -EBADMSG;
 
 decrypt:
 
-	sg_init_table(areq_ctx->dst, 2);
+	if (src != dst)
+		src = scatterwalk_ffwd(areq_ctx->src, src, assoclen);
 	dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen);
 
 	skcipher_request_set_tfm(skreq, ctx->enc);
 	skcipher_request_set_callback(skreq, flags,
 				      req->base.complete, req->base.data);
-	skcipher_request_set_crypt(skreq, dst, dst, cryptlen, req->iv);
+	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);
 
 	return crypto_skcipher_decrypt(skreq);
 }
 
 static void authenc_esn_verify_ahash_done(void *data, int err)

@@ -253,35 +258,40 @@ static int crypto_authenc_esn_decrypt(struct aead_request *req)
 	struct crypto_ahash *auth = ctx->auth;
 	u8 *ohash = areq_ctx->tail;
 	unsigned int assoclen = req->assoclen;
 	unsigned int cryptlen = req->cryptlen;
 	u8 *ihash = ohash + crypto_ahash_digestsize(auth);
+	struct scatterlist *src = req->src;
 	struct scatterlist *dst = req->dst;
 	u32 tmp[2];
 	int err;
 
 	if (assoclen < 8)
 		return -EINVAL;
 
-	cryptlen -= authsize;
-
-	if (req->src != dst)
-		memcpy_sglist(dst, req->src, assoclen + cryptlen);
+	if (!authsize)
+		goto tail;
 
+	cryptlen -= authsize;
 	scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen,
 				 authsize, 0);
 
-	if (!authsize)
-		goto tail;
-
 	/* Move high-order bits of sequence number to the end. */
-	scatterwalk_map_and_copy(tmp, dst, 0, 8, 0);
-	scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
-	scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
-
-	sg_init_table(areq_ctx->dst, 2);
-	dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
+	scatterwalk_map_and_copy(tmp, src, 0, 8, 0);
+	if (src == dst) {
+		scatterwalk_map_and_copy(tmp, dst, 4, 4, 1);
+		scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1);
+		dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
+	} else {
+		scatterwalk_map_and_copy(tmp, dst, 0, 4, 1);
+		scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen - 4, 4, 1);
+
+		src = scatterwalk_ffwd(areq_ctx->src, src, 8);
+		dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4);
+		memcpy_sglist(dst, src, assoclen + cryptlen - 8);
+		dst = req->dst;
+	}
 
 	ahash_request_set_tfm(ahreq, auth);
 	ahash_request_set_crypt(ahreq, dst, ohash, assoclen + cryptlen);
 	ahash_request_set_callback(ahreq, aead_request_flags(req),
 				   authenc_esn_verify_ahash_done, req);

index 257af38ac4de..c01cc3087919 100644
@@ -226,13 +226,15 @@ static int crypto_authenc_esn_decrypt_tail(struct aead_request *req,
 	if (crypto_memneq(ihash, ohash, authsize))
 		return -EBADMSG;
 
 decrypt:
 
-	if (src != dst)
-		src = scatterwalk_ffwd(areq_ctx->src, src, assoclen);
 	dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen);
+	if (req->src == req->dst)
+		src = dst;
+	else
+		src = scatterwalk_ffwd(areq_ctx->src, src, assoclen);
 
 	skcipher_request_set_tfm(skreq, ctx->enc);
 	skcipher_request_set_callback(skreq, flags,
 				      req->base.complete, req->base.data);
 	skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv);

index 6867d177f2a2..b61c3ba126ed 100644
@@ -703,12 +703,12 @@ void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst)
 
 			/*
 			 * Assumption: caller created af_alg_count_tsgl(len)
 			 * SG entries in dst.
 			 */
-			if (dst) {
-				/* reassign page to dst after offset */
+			if (dst && plen) {
+				/* reassign page to dst */
 				get_page(page);
 				sg_set_page(dst + j, page, plen, sg[i].offset);
 				j++;
 			}