--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -914,24 +914,25 @@ static int test_pcomp(struct crypto_pcom
 	const char *algo = crypto_tfm_alg_driver_name(crypto_pcomp_tfm(tfm));
 	unsigned int i;
 	char result[COMP_BUF_SIZE];
-	int error;
+	int res;
 
 	for (i = 0; i < ctcount; i++) {
 		struct comp_request req;
+		unsigned int produced = 0;
 
-		error = crypto_compress_setup(tfm, ctemplate[i].params,
-					      ctemplate[i].paramsize);
-		if (error) {
+		res = crypto_compress_setup(tfm, ctemplate[i].params,
+					    ctemplate[i].paramsize);
+		if (res) {
 			pr_err("alg: pcomp: compression setup failed on test "
-			       "%d for %s: error=%d\n", i + 1, algo, error);
-			return error;
+			       "%d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
 
-		error = crypto_compress_init(tfm);
-		if (error) {
+		res = crypto_compress_init(tfm);
+		if (res) {
 			pr_err("alg: pcomp: compression init failed on test "
-			       "%d for %s: error=%d\n", i + 1, algo, error);
-			return error;
+			       "%d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
 
 		memset(result, 0, sizeof(result));
@@ -941,32 +942,37 @@ static int test_pcomp(struct crypto_pcom
 		req.next_out = result;
 		req.avail_out = ctemplate[i].outlen / 2;
 
-		error = crypto_compress_update(tfm, &req);
-		if (error && (error != -EAGAIN || req.avail_in)) {
+		res = crypto_compress_update(tfm, &req);
+		if (res < 0 && (res != -EAGAIN || req.avail_in)) {
 			pr_err("alg: pcomp: compression update failed on test "
-			       "%d for %s: error=%d\n", i + 1, algo, error);
-			return error;
+			       "%d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
+		if (res > 0)
+			produced += res;
 
 		/* Add remaining input data */
 		req.avail_in += (ctemplate[i].inlen + 1) / 2;
 
-		error = crypto_compress_update(tfm, &req);
-		if (error && (error != -EAGAIN || req.avail_in)) {
+		res = crypto_compress_update(tfm, &req);
+		if (res < 0 && (res != -EAGAIN || req.avail_in)) {
 			pr_err("alg: pcomp: compression update failed on test "
-			       "%d for %s: error=%d\n", i + 1, algo, error);
-			return error;
+			       "%d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
+		if (res > 0)
+			produced += res;
 
 		/* Provide remaining output space */
 		req.avail_out += COMP_BUF_SIZE - ctemplate[i].outlen / 2;
 
-		error = crypto_compress_final(tfm, &req);
-		if (error) {
+		res = crypto_compress_final(tfm, &req);
+		if (res < 0) {
 			pr_err("alg: pcomp: compression final failed on test "
-			       "%d for %s: error=%d\n", i + 1, algo, error);
-			return error;
+			       "%d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
+		produced += res;
 
 		if (COMP_BUF_SIZE - req.avail_out != ctemplate[i].outlen) {
 			pr_err("alg: comp: Compression test %d failed for %s: "
@@ -976,6 +982,13 @@ static int test_pcomp(struct crypto_pcom
 			return -EINVAL;
 		}
 
+		if (produced != ctemplate[i].outlen) {
+			pr_err("alg: comp: Compression test %d failed for %s: "
+			       "returned len = %u (expected %d)\n", i + 1,
+			       algo, produced, ctemplate[i].outlen);
+			return -EINVAL;
+		}
+
 		if (memcmp(result, ctemplate[i].output, ctemplate[i].outlen)) {
 			pr_err("alg: pcomp: Compression test %d failed for "
 			       "%s\n", i + 1, algo);
@@ -986,21 +999,21 @@ static int test_pcomp(struct crypto_pcom
 
 	for (i = 0; i < dtcount; i++) {
 		struct comp_request req;
+		unsigned int produced = 0;
 
-		error = crypto_decompress_setup(tfm, dtemplate[i].params,
-						dtemplate[i].paramsize);
-		if (error) {
+		res = crypto_decompress_setup(tfm, dtemplate[i].params,
+					      dtemplate[i].paramsize);
+		if (res) {
 			pr_err("alg: pcomp: decompression setup failed on "
-			       "test %d for %s: error=%d\n", i + 1, algo,
-			       error);
-			return error;
+			       "test %d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
 
-		error = crypto_decompress_init(tfm);
-		if (error) {
+		res = crypto_decompress_init(tfm);
+		if (res) {
 			pr_err("alg: pcomp: decompression init failed on test "
-			       "%d for %s: error=%d\n", i + 1, algo, error);
-			return error;
+			       "%d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
 
 		memset(result, 0, sizeof(result));
@@ -1010,35 +1023,38 @@ static int test_pcomp(struct crypto_pcom
 		req.next_out = result;
 		req.avail_out = dtemplate[i].outlen / 2;
 
-		error = crypto_decompress_update(tfm, &req);
-		if (error  && (error != -EAGAIN || req.avail_in)) {
+		res = crypto_decompress_update(tfm, &req);
+		if (res < 0 && (res != -EAGAIN || req.avail_in)) {
 			pr_err("alg: pcomp: decompression update failed on "
-			       "test %d for %s: error=%d\n", i + 1, algo,
-			       error);
-			return error;
+			       "test %d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
+		if (res > 0)
+			produced += res;
 
 		/* Add remaining input data */
 		req.avail_in += (dtemplate[i].inlen + 1) / 2;
 
-		error = crypto_decompress_update(tfm, &req);
-		if (error  && (error != -EAGAIN || req.avail_in)) {
+		res = crypto_decompress_update(tfm, &req);
+		if (res < 0 && (res != -EAGAIN || req.avail_in)) {
 			pr_err("alg: pcomp: decompression update failed on "
-			       "test %d for %s: error=%d\n", i + 1, algo,
-			       error);
-			return error;
+			       "test %d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
+		if (res > 0)
+			produced += res;
 
 		/* Provide remaining output space */
 		req.avail_out += COMP_BUF_SIZE - dtemplate[i].outlen / 2;
 
-		error = crypto_decompress_final(tfm, &req);
-		if (error  && (error != -EAGAIN || req.avail_in)) {
+		res = crypto_decompress_final(tfm, &req);
+		if (res < 0 && (res != -EAGAIN || req.avail_in)) {
 			pr_err("alg: pcomp: decompression final failed on "
-			       "test %d for %s: error=%d\n", i + 1, algo,
-			       error);
-			return error;
+			       "test %d for %s: error=%d\n", i + 1, algo, res);
+			return res;
 		}
+		if (res > 0)
+			produced += res;
 
 		if (COMP_BUF_SIZE - req.avail_out != dtemplate[i].outlen) {
 			pr_err("alg: comp: Decompression test %d failed for "
@@ -1048,6 +1064,13 @@ static int test_pcomp(struct crypto_pcom
 			return -EINVAL;
 		}
 
+		if (produced != dtemplate[i].outlen) {
+			pr_err("alg: comp: Decompression test %d failed for "
+			       "%s: returned len = %u (expected %d)\n", i + 1,
+			       algo, produced, dtemplate[i].outlen);
+			return -EINVAL;
+		}
+
 		if (memcmp(result, dtemplate[i].output, dtemplate[i].outlen)) {
 			pr_err("alg: pcomp: Decompression test %d failed for "
 			       "%s\n", i + 1, algo);
--- a/crypto/zlib.c
+++ b/crypto/zlib.c
@@ -165,15 +165,15 @@ static int zlib_compress_update(struct c
 		return -EINVAL;
 	}
 
+	ret = req->avail_out - stream->avail_out;
 	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 		 stream->avail_in, stream->avail_out,
-		 req->avail_in - stream->avail_in,
-		 req->avail_out - stream->avail_out);
+		 req->avail_in - stream->avail_in, ret);
 	req->next_in = stream->next_in;
 	req->avail_in = stream->avail_in;
 	req->next_out = stream->next_out;
 	req->avail_out = stream->avail_out;
-	return 0;
+	return ret;
 }
 
 static int zlib_compress_final(struct crypto_pcomp *tfm,
@@ -195,15 +195,15 @@ static int zlib_compress_final(struct cr
 		return -EINVAL;
 	}
 
+	ret = req->avail_out - stream->avail_out;
 	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 		 stream->avail_in, stream->avail_out,
-		 req->avail_in - stream->avail_in,
-		 req->avail_out - stream->avail_out);
+		 req->avail_in - stream->avail_in, ret);
 	req->next_in = stream->next_in;
 	req->avail_in = stream->avail_in;
 	req->next_out = stream->next_out;
 	req->avail_out = stream->avail_out;
-	return 0;
+	return ret;
 }
 
 
@@ -280,15 +280,15 @@ static int zlib_decompress_update(struct
 		return -EINVAL;
 	}
 
+	ret = req->avail_out - stream->avail_out;
 	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 		 stream->avail_in, stream->avail_out,
-		 req->avail_in - stream->avail_in,
-		 req->avail_out - stream->avail_out);
+		 req->avail_in - stream->avail_in, ret);
 	req->next_in = stream->next_in;
 	req->avail_in = stream->avail_in;
 	req->next_out = stream->next_out;
 	req->avail_out = stream->avail_out;
-	return 0;
+	return ret;
 }
 
 static int zlib_decompress_final(struct crypto_pcomp *tfm,
@@ -328,15 +328,15 @@ static int zlib_decompress_final(struct 
 		return -EINVAL;
 	}
 
+	ret = req->avail_out - stream->avail_out;
 	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 		 stream->avail_in, stream->avail_out,
-		 req->avail_in - stream->avail_in,
-		 req->avail_out - stream->avail_out);
+		 req->avail_in - stream->avail_in, ret);
 	req->next_in = stream->next_in;
 	req->avail_in = stream->avail_in;
 	req->next_out = stream->next_out;
 	req->avail_out = stream->avail_out;
-	return 0;
+	return ret;
 }