diff --git a/fs/proc/array.c b/fs/proc/array.c
index 1295a00ca316..b5405889a780 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -99,8 +99,8 @@ static inline void task_name(struct seq_file *m, struct task_struct *p)
 	buf = m->buf + m->count;
 
 	/* Ignore error for now */
-	string_escape_str(tcomm, &buf, m->size - m->count,
-			  ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
+	buf += string_escape_str(tcomm, buf, m->size - m->count,
+				 ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
 
 	m->count = buf - m->buf;
 	seq_putc(m, '\n');
diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index 657571817260..0991913f4953 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -47,22 +47,22 @@ static inline int string_unescape_any_inplace(char *buf)
 #define ESCAPE_ANY_NP		(ESCAPE_ANY | ESCAPE_NP)
 #define ESCAPE_HEX		0x20
 
-int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
+int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
 		unsigned int flags, const char *esc);
 
 static inline int string_escape_mem_any_np(const char *src, size_t isz,
-		char **dst, size_t osz, const char *esc)
+		char *dst, size_t osz, const char *esc)
 {
 	return string_escape_mem(src, isz, dst, osz, ESCAPE_ANY_NP, esc);
 }
 
-static inline int string_escape_str(const char *src, char **dst, size_t sz,
+static inline int string_escape_str(const char *src, char *dst, size_t sz,
 		unsigned int flags, const char *esc)
 {
 	return string_escape_mem(src, strlen(src), dst, sz, flags, esc);
 }
 
-static inline int string_escape_str_any_np(const char *src, char **dst,
+static inline int string_escape_str_any_np(const char *src, char *dst,
 		size_t sz, const char *esc)
 {
 	return string_escape_str(src, dst, sz, ESCAPE_ANY_NP, esc);
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 9c48ddad0f0d..1826c7407258 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -274,11 +274,6 @@ static bool escape_space(unsigned char c, char **dst, char *end)
 		return false;
 	}
 
-	if (out + 2 > end) {
-		*dst = out + 2;
-		return true;
-	}
-
 	if (out < end)
 		*out = '\\';
 	++out;
@@ -309,11 +304,6 @@ static bool escape_special(unsigned char c, char **dst, char *end)
 		return false;
 	}
 
-	if (out + 2 > end) {
-		*dst = out + 2;
-		return true;
-	}
-
 	if (out < end)
 		*out = '\\';
 	++out;
@@ -332,11 +322,6 @@ static bool escape_null(unsigned char c, char **dst, char *end)
 	if (c)
 		return false;
 
-	if (out + 2 > end) {
-		*dst = out + 2;
-		return true;
-	}
-
 	if (out < end)
 		*out = '\\';
 	++out;
@@ -352,11 +337,6 @@ static bool escape_octal(unsigned char c, char **dst, char *end)
 {
 	char *out = *dst;
 
-	if (out + 4 > end) {
-		*dst = out + 4;
-		return true;
-	}
-
 	if (out < end)
 		*out = '\\';
 	++out;
@@ -378,11 +358,6 @@ static bool escape_hex(unsigned char c, char **dst, char *end)
 {
 	char *out = *dst;
 
-	if (out + 4 > end) {
-		*dst = out + 4;
-		return true;
-	}
-
 	if (out < end)
 		*out = '\\';
 	++out;
@@ -449,20 +424,17 @@ static bool escape_hex(unsigned char c, char **dst, char *end)
  * it if needs.
  *
  * Return:
- * The amount of the characters processed to the destination buffer, or
- * %-ENOMEM if the size of buffer is not enough to put an escaped character is
- * returned.
- *
- * Even in the case of error @dst pointer will be updated to point to the byte
- * after the last processed character.
+ * The total size of the escaped output that would be generated for
+ * the given input and flags. To check whether the output was
+ * truncated, compare the return value to osz. There is room left in
+ * dst for a '\0' terminator if and only if ret < osz.
  */
-int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
+int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
 		      unsigned int flags, const char *esc)
 {
-	char *p = *dst;
+	char *p = dst;
 	char *end = p + osz;
 	bool is_dict = esc && *esc;
-	int ret;
 
 	while (isz--) {
 		unsigned char c = *src++;
@@ -502,13 +474,6 @@ int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
 		escape_passthrough(c, &p, end);
 	}
 
-	if (p > end) {
-		*dst = end;
-		return -ENOMEM;
-	}
-
-	ret = p - *dst;
-	*dst = p;
-	return ret;
+	return p - dst;
 }
 EXPORT_SYMBOL(string_escape_mem);
diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c
index ab0d30e1e18f..8e376efd88a4 100644
--- a/lib/test-string_helpers.c
+++ b/lib/test-string_helpers.c
@@ -260,16 +260,28 @@ static __init const char *test_string_find_match(const struct test_string_2 *s2,
 	return NULL;
 }
 
+static __init void
+test_string_escape_overflow(const char *in, int p, unsigned int flags, const char *esc,
+			    int q_test, const char *name)
+{
+	int q_real;
+
+	q_real = string_escape_mem(in, p, NULL, 0, flags, esc);
+	if (q_real != q_test)
+		pr_warn("Test '%s' failed: flags = %u, osz = 0, expected %d, got %d\n",
+			name, flags, q_test, q_real);
+}
+
 static __init void test_string_escape(const char *name,
 				      const struct test_string_2 *s2,
 				      unsigned int flags, const char *esc)
 {
-	int q_real = 512;
-	char *out_test = kmalloc(q_real, GFP_KERNEL);
-	char *out_real = kmalloc(q_real, GFP_KERNEL);
+	size_t out_size = 512;
+	char *out_test = kmalloc(out_size, GFP_KERNEL);
+	char *out_real = kmalloc(out_size, GFP_KERNEL);
 	char *in = kmalloc(256, GFP_KERNEL);
-	char *buf = out_real;
 	int p = 0, q_test = 0;
+	int q_real;
 
 	if (!out_test || !out_real || !in)
 		goto out;
@@ -301,29 +313,19 @@ static __init void test_string_escape(const char *name,
 		q_test += len;
 	}
 
-	q_real = string_escape_mem(in, p, &buf, q_real, flags, esc);
+	q_real = string_escape_mem(in, p, out_real, out_size, flags, esc);
 
 	test_string_check_buf(name, flags, in, p, out_real, q_real, out_test,
 			      q_test);
+
+	test_string_escape_overflow(in, p, flags, esc, q_test, name);
+
 out:
 	kfree(in);
 	kfree(out_real);
 	kfree(out_test);
 }
 
-static __init void test_string_escape_nomem(void)
-{
-	char *in = "\eb \\C\007\"\x90\r]";
-	char out[64], *buf = out;
-	int rc = -ENOMEM, ret;
-
-	ret = string_escape_str_any_np(in, &buf, strlen(in), NULL);
-	if (ret == rc)
-		return;
-
-	pr_err("Test 'escape nomem' failed: got %d instead of %d\n", ret, rc);
-}
-
 static int __init test_string_helpers_init(void)
 {
 	unsigned int i;
@@ -342,8 +344,6 @@ static int __init test_string_helpers_init(void)
 	for (i = 0; i < (ESCAPE_ANY_NP | ESCAPE_HEX) + 1; i++)
 		test_string_escape("escape 1", escape1, i, TEST_STRING_2_DICT_1);
 
-	test_string_escape_nomem();
-
 	return -EINVAL;
 }
 module_init(test_string_helpers_init);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index a1b6487c6710..9651686f3b42 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1241,8 +1241,12 @@ char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 
 	len = spec.field_width < 0 ? 1 : spec.field_width;
 
-	/* Ignore the error. We print as many characters as we can */
-	string_escape_mem(addr, len, &buf, end - buf, flags, NULL);
+	/*
+	 * string_escape_mem() writes as many characters as it can to
+	 * the given buffer, and returns the total size of the output
+	 * had the buffer been big enough.
+	 */
+	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
 
 	return buf;
 }
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 33fb105d4352..22c4418057f4 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1068,12 +1068,14 @@ void qword_add(char **bpp, int *lp, char *str)
 {
 	char *bp = *bpp;
 	int len = *lp;
-	int ret;
+	int ret, written;
 
 	if (len < 0) return;
 
-	ret = string_escape_str(str, &bp, len, ESCAPE_OCTAL, "\\ \n\t");
-	if (ret < 0 || ret == len)
+	ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t");
+	written = min(ret, len);
+	bp += written;
+	if (ret >= len)
 		len = -1;
 	else {
 		len -= ret;
