cifs: clean up unaligned accesses in cifs_unicode.c

Make sure we use get/put_unaligned routines when accessing wide
character strings.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 28 insertions, 23 deletions

diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
index 430f510a1720..5f6e71857be6 100644
--- a/fs/cifs/cifs_unicode.c
+++ b/fs/cifs/cifs_unicode.c
@@ -44,10 +44,14 @@ cifs_ucs2_bytes(const __le16 *from, int maxbytes,
         int charlen, outlen = 0;
         int maxwords = maxbytes / 2;
         char tmp[NLS_MAX_CHARSET_SIZE];
+        __u16 ftmp;
 
-        for (i = 0; i < maxwords && from[i]; i++) {
-                charlen = codepage->uni2char(le16_to_cpu(from[i]), tmp,
-                                             NLS_MAX_CHARSET_SIZE);
+        for (i = 0; i < maxwords; i++) {
+                ftmp = get_unaligned_le16(&from[i]);
+                if (ftmp == 0)
+                        break;
+
+                charlen = codepage->uni2char(ftmp, tmp, NLS_MAX_CHARSET_SIZE);
                 if (charlen > 0)
                         outlen += charlen;
                 else
@@ -58,9 +62,9 @@ cifs_ucs2_bytes(const __le16 *from, int maxbytes,
 }
 
 /*
- * cifs_mapchar - convert a little-endian char to proper char in codepage
+ * cifs_mapchar - convert a host-endian char to proper char in codepage
  * @target - where converted character should be copied
- * @src_char - 2 byte little-endian source character
+ * @src_char - 2 byte host-endian source character
  * @cp - codepage to which character should be converted
  * @mapchar - should character be mapped according to mapchars mount option?
  *
@@ -69,7 +73,7 @@ cifs_ucs2_bytes(const __le16 *from, int maxbytes,
  * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE).
  */
 static int
-cifs_mapchar(char *target, const __le16 src_char, const struct nls_table *cp,
+cifs_mapchar(char *target, const __u16 src_char, const struct nls_table *cp,
              bool mapchar)
 {
         int len = 1;
@@ -82,7 +86,7 @@ cifs_mapchar(char *target, const __le16 src_char, const struct nls_table *cp,
          *     build_path_from_dentry are modified, as they use slash as
          *     separator.
          */
-        switch (le16_to_cpu(src_char)) {
+        switch (src_char) {
         case UNI_COLON:
                 *target = ':';
                 break;
@@ -109,8 +113,7 @@ out:
         return len;
 
 cp_convert:
-        len = cp->uni2char(le16_to_cpu(src_char), target,
-                           NLS_MAX_CHARSET_SIZE);
+        len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE);
         if (len <= 0) {
                 *target = '?';
                 len = 1;
@@ -149,6 +152,7 @@ cifs_from_ucs2(char *to, const __le16 *from, int tolen, int fromlen,
         int nullsize = nls_nullsize(codepage);
         int fromwords = fromlen / 2;
         char tmp[NLS_MAX_CHARSET_SIZE];
+        __u16 ftmp;
 
         /*
          * because the chars can be of varying widths, we need to take care
@@ -158,19 +162,23 @@ cifs_from_ucs2(char *to, const __le16 *from, int tolen, int fromlen,
          */
         safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize);
 
-        for (i = 0; i < fromwords && from[i]; i++) {
+        for (i = 0; i < fromwords; i++) {
+                ftmp = get_unaligned_le16(&from[i]);
+                if (ftmp == 0)
+                        break;
+
                 /*
                  * check to see if converting this character might make the
                  * conversion bleed into the null terminator
                  */
                 if (outlen >= safelen) {
-                        charlen = cifs_mapchar(tmp, from[i], codepage, mapchar);
+                        charlen = cifs_mapchar(tmp, ftmp, codepage, mapchar);
                         if ((outlen + charlen) > (tolen - nullsize))
                                 break;
                 }
 
                 /* put converted char into 'to' buffer */
-                charlen = cifs_mapchar(&to[outlen], from[i], codepage, mapchar);
+                charlen = cifs_mapchar(&to[outlen], ftmp, codepage, mapchar);
                 outlen += charlen;
         }
 
@@ -193,24 +201,21 @@ cifs_strtoUCS(__le16 *to, const char *from, int len,
 {
         int charlen;
         int i;
-        wchar_t *wchar_to = (wchar_t *)to; /* needed to quiet sparse */
+        wchar_t wchar_to; /* needed to quiet sparse */
 
         for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
-
-                /* works for 2.4.0 kernel or later */
-                charlen = codepage->char2uni(from, len, &wchar_to[i]);
+                charlen = codepage->char2uni(from, len, &wchar_to);
                 if (charlen < 1) {
-                        cERROR(1, "strtoUCS: char2uni of %d returned %d",
-                                (int)*from, charlen);
+                        cERROR(1, "strtoUCS: char2uni of 0x%x returned %d",
+                                *from, charlen);
                         /* A question mark */
-                        to[i] = cpu_to_le16(0x003f);
+                        wchar_to = 0x003f;
                         charlen = 1;
-                } else
-                        to[i] = cpu_to_le16(wchar_to[i]);
-
+                }
+                put_unaligned_le16(wchar_to, &to[i]);
         }
 
-        to[i] = 0;
+        put_unaligned_le16(0, &to[i]);
         return i;
 }