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Commit ba2dbf30 authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

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: default avatarJeff Layton <jlayton@redhat.com>
Acked-by: default avatarPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: default avatarShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 26ec2548

fs/cifs/cifs_unicode.c

+28 −23
Original line number Diff line number Diff line
@@ -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 @@ cifs_mapchar(char *target, const __le16 src_char, const struct nls_table *cp, 
	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;

}