diff --git a/crypto/deflate.c b/crypto/deflate.c
index 0955040ca9e64146..112683473df2b588 100644
--- a/crypto/deflate.c
+++ b/crypto/deflate.c
@@ -6,246 +6,154 @@
  * by IPCOMP (RFC 3173 & RFC 2394).
  *
  * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
- *
- * FIXME: deflate transforms will require up to a total of about 436k of kernel
- * memory on i386 (390k for compression, the rest for decompression), as the
- * current zlib kernel code uses a worst case pre-allocation system by default.
- * This needs to be fixed so that the amount of memory required is properly
- * related to the  winbits and memlevel parameters.
- *
- * The default winbits of 11 should suit most packets, and it may be something
- * to configure on a per-tfm basis in the future.
- *
- * Currently, compression history is not maintained between tfm calls, as
- * it is not needed for IPCOMP and keeps the code simpler.  It can be
- * implemented if someone wants it.
+ * Copyright (c) 2023 Google, LLC. <ardb@kernel.org>
  */
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/crypto.h>
 #include <linux/zlib.h>
-#include <linux/vmalloc.h>
-#include <linux/interrupt.h>
-#include <linux/mm.h>
 #include <linux/net.h>
-#include <crypto/internal/scompress.h>
+#include <linux/scatterlist.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/internal/acompress.h>
 
 #define DEFLATE_DEF_LEVEL		Z_DEFAULT_COMPRESSION
 #define DEFLATE_DEF_WINBITS		11
 #define DEFLATE_DEF_MEMLEVEL		MAX_MEM_LEVEL
 
-struct deflate_ctx {
-	struct z_stream_s comp_stream;
-	struct z_stream_s decomp_stream;
+struct deflate_req_ctx {
+	struct z_stream_s stream;
+	u8 workspace[];
 };
 
-static int deflate_comp_init(struct deflate_ctx *ctx)
+static int deflate_process(struct acomp_req *req, struct z_stream_s *stream,
+			   int (*process)(struct z_stream_s *, int))
 {
-	int ret = 0;
-	struct z_stream_s *stream = &ctx->comp_stream;
+	unsigned int slen = req->slen;
+	unsigned int dlen = req->dlen;
+	struct scatter_walk src, dst;
+	unsigned int scur, dcur;
+	int ret;
 
-	stream->workspace = vzalloc(zlib_deflate_workspacesize(
-				-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL));
-	if (!stream->workspace) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	stream->avail_in = stream->avail_out = 0;
+
+	scatterwalk_start(&src, req->src);
+	scatterwalk_start(&dst, req->dst);
+
+	scur = dcur = 0;
+
+	do {
+		if (stream->avail_in == 0) {
+			if (scur) {
+				slen -= scur;
+
+				scatterwalk_unmap(stream->next_in - scur);
+				scatterwalk_advance(&src, scur);
+				scatterwalk_done(&src, 0, slen);
+			}
+
+			scur = scatterwalk_clamp(&src, slen);
+			if (scur) {
+				stream->next_in = scatterwalk_map(&src);
+				stream->avail_in = scur;
+			}
+		}
+
+		if (stream->avail_out == 0) {
+			if (dcur) {
+				dlen -= dcur;
+
+				scatterwalk_unmap(stream->next_out - dcur);
+				scatterwalk_advance(&dst, dcur);
+				scatterwalk_done(&dst, 1, dlen);
+			}
+
+			dcur = scatterwalk_clamp(&dst, dlen);
+			if (!dcur)
+				break;
+
+			stream->next_out = scatterwalk_map(&dst);
+			stream->avail_out = dcur;
+		}
+
+		ret = process(stream, (slen == scur) ? Z_FINISH : Z_SYNC_FLUSH);
+	} while (ret == Z_OK);
+
+	if (scur)
+		scatterwalk_unmap(stream->next_in - scur);
+	if (dcur)
+		scatterwalk_unmap(stream->next_out - dcur);
+
+	if (ret != Z_STREAM_END)
+		return -EINVAL;
+
+	req->dlen = stream->total_out;
+	return 0;
+}
+
+static int deflate_compress(struct acomp_req *req)
+{
+	struct deflate_req_ctx *ctx = acomp_request_ctx(req);
+	struct z_stream_s *stream = &ctx->stream;
+	int ret;
+
+        if (!req->src || !req->slen || !req->dst || !req->dlen)
+                return -EINVAL;
+
+	stream->workspace = ctx->workspace;
 	ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
 	                        -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
 	                        Z_DEFAULT_STRATEGY);
-	if (ret != Z_OK) {
-		ret = -EINVAL;
-		goto out_free;
-	}
-out:
+	if (ret != Z_OK)
+		return -EINVAL;
+
+	ret = deflate_process(req, stream, zlib_deflate);
+	zlib_deflateEnd(stream);
 	return ret;
-out_free:
-	vfree(stream->workspace);
-	goto out;
 }
 
-static int deflate_decomp_init(struct deflate_ctx *ctx)
+static int deflate_decompress(struct acomp_req *req)
 {
-	int ret = 0;
-	struct z_stream_s *stream = &ctx->decomp_stream;
+	struct deflate_req_ctx *ctx = acomp_request_ctx(req);
+	struct z_stream_s *stream = &ctx->stream;
+	int ret;
 
-	stream->workspace = vzalloc(zlib_inflate_workspacesize());
-	if (!stream->workspace) {
-		ret = -ENOMEM;
-		goto out;
-	}
+        if (!req->src || !req->slen || !req->dst || !req->dlen)
+                return -EINVAL;
+
+	stream->workspace = ctx->workspace;
 	ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
-	if (ret != Z_OK) {
-		ret = -EINVAL;
-		goto out_free;
-	}
-out:
-	return ret;
-out_free:
-	vfree(stream->workspace);
-	goto out;
-}
+	if (ret != Z_OK)
+		return -EINVAL;
 
-static void deflate_comp_exit(struct deflate_ctx *ctx)
-{
-	zlib_deflateEnd(&ctx->comp_stream);
-	vfree(ctx->comp_stream.workspace);
-}
-
-static void deflate_decomp_exit(struct deflate_ctx *ctx)
-{
-	zlib_inflateEnd(&ctx->decomp_stream);
-	vfree(ctx->decomp_stream.workspace);
-}
-
-static int __deflate_init(void *ctx)
-{
-	int ret;
-
-	ret = deflate_comp_init(ctx);
-	if (ret)
-		goto out;
-	ret = deflate_decomp_init(ctx);
-	if (ret)
-		deflate_comp_exit(ctx);
-out:
+	ret = deflate_process(req, stream, zlib_inflate);
+	req->dlen = stream->total_out;
+	zlib_inflateEnd(stream);
 	return ret;
 }
 
-static void *deflate_alloc_ctx(struct crypto_scomp *tfm)
-{
-	struct deflate_ctx *ctx;
-	int ret;
+static struct acomp_alg alg = {
+	.compress		= deflate_compress,
+	.decompress		= deflate_decompress,
 
-	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
-	if (!ctx)
-		return ERR_PTR(-ENOMEM);
-
-	ret = __deflate_init(ctx);
-	if (ret) {
-		kfree(ctx);
-		return ERR_PTR(ret);
-	}
-
-	return ctx;
-}
-
-static void __deflate_exit(void *ctx)
-{
-	deflate_comp_exit(ctx);
-	deflate_decomp_exit(ctx);
-}
-
-static void deflate_free_ctx(struct crypto_scomp *tfm, void *ctx)
-{
-	__deflate_exit(ctx);
-	kfree_sensitive(ctx);
-}
-
-static int __deflate_compress(const u8 *src, unsigned int slen,
-			      u8 *dst, unsigned int *dlen, void *ctx)
-{
-	int ret = 0;
-	struct deflate_ctx *dctx = ctx;
-	struct z_stream_s *stream = &dctx->comp_stream;
-
-	ret = zlib_deflateReset(stream);
-	if (ret != Z_OK) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	stream->next_in = (u8 *)src;
-	stream->avail_in = slen;
-	stream->next_out = (u8 *)dst;
-	stream->avail_out = *dlen;
-
-	ret = zlib_deflate(stream, Z_FINISH);
-	if (ret != Z_STREAM_END) {
-		ret = -EINVAL;
-		goto out;
-	}
-	ret = 0;
-	*dlen = stream->total_out;
-out:
-	return ret;
-}
-
-static int deflate_scompress(struct crypto_scomp *tfm, const u8 *src,
-			     unsigned int slen, u8 *dst, unsigned int *dlen,
-			     void *ctx)
-{
-	return __deflate_compress(src, slen, dst, dlen, ctx);
-}
-
-static int __deflate_decompress(const u8 *src, unsigned int slen,
-				u8 *dst, unsigned int *dlen, void *ctx)
-{
-
-	int ret = 0;
-	struct deflate_ctx *dctx = ctx;
-	struct z_stream_s *stream = &dctx->decomp_stream;
-
-	ret = zlib_inflateReset(stream);
-	if (ret != Z_OK) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	stream->next_in = (u8 *)src;
-	stream->avail_in = slen;
-	stream->next_out = (u8 *)dst;
-	stream->avail_out = *dlen;
-
-	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
-	/*
-	 * Work around a bug in zlib, which sometimes wants to taste an extra
-	 * byte when being used in the (undocumented) raw deflate mode.
-	 * (From USAGI).
-	 */
-	if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
-		u8 zerostuff = 0;
-		stream->next_in = &zerostuff;
-		stream->avail_in = 1;
-		ret = zlib_inflate(stream, Z_FINISH);
-	}
-	if (ret != Z_STREAM_END) {
-		ret = -EINVAL;
-		goto out;
-	}
-	ret = 0;
-	*dlen = stream->total_out;
-out:
-	return ret;
-}
-
-static int deflate_sdecompress(struct crypto_scomp *tfm, const u8 *src,
-			       unsigned int slen, u8 *dst, unsigned int *dlen,
-			       void *ctx)
-{
-	return __deflate_decompress(src, slen, dst, dlen, ctx);
-}
-
-static struct scomp_alg scomp = {
-	.alloc_ctx		= deflate_alloc_ctx,
-	.free_ctx		= deflate_free_ctx,
-	.compress		= deflate_scompress,
-	.decompress		= deflate_sdecompress,
-	.base			= {
-		.cra_name	= "deflate",
-		.cra_driver_name = "deflate-scomp",
-		.cra_module	 = THIS_MODULE,
-	}
+	.base.cra_name		= "deflate",
+	.base.cra_driver_name	= "deflate-generic",
+	.base.cra_module	= THIS_MODULE,
 };
 
 static int __init deflate_mod_init(void)
 {
-	return crypto_register_scomp(&scomp);
+	size_t size = max(zlib_inflate_workspacesize(),
+			  zlib_deflate_workspacesize(-DEFLATE_DEF_WINBITS,
+						     DEFLATE_DEF_MEMLEVEL));
+
+	alg.reqsize = struct_size_t(struct deflate_req_ctx, workspace, size);
+	return crypto_register_acomp(&alg);
 }
 
 static void __exit deflate_mod_fini(void)
 {
-	crypto_unregister_scomp(&scomp);
+	crypto_unregister_acomp(&alg);
 }
 
 subsys_initcall(deflate_mod_init);
@@ -254,4 +162,5 @@ module_exit(deflate_mod_fini);
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
+MODULE_AUTHOR("Ard Biesheuvel <ardb@kernel.org>");
 MODULE_ALIAS_CRYPTO("deflate");
diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h
index 32fc4473175b1d81..46dc7b21bf9ecbd0 100644
--- a/include/crypto/scatterwalk.h
+++ b/include/crypto/scatterwalk.h
@@ -51,7 +51,7 @@ static inline struct page *scatterwalk_page(struct scatter_walk *walk)
 	return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
 }
 
-static inline void scatterwalk_unmap(void *vaddr)
+static inline void scatterwalk_unmap(const void *vaddr)
 {
 	kunmap_local(vaddr);
 }
