Commit dbab80e2 authored by Atte Heikkilä's avatar Atte Heikkilä Committed by Steve French
Browse files

ksmbd: make utf-8 file name comparison work in __caseless_lookup() 



Case-insensitive file name lookups with __caseless_lookup() use
strncasecmp() for file name comparison. strncasecmp() assumes an
ISO8859-1-compatible encoding, which is not the case here as UTF-8
is always used. As such, use of strncasecmp() here produces correct
results only if both strings use characters in the ASCII range only.
Fix this by using utf8_strncasecmp() if CONFIG_UNICODE is set. On
failure or if CONFIG_UNICODE is not set, fallback to strncasecmp().
Also, as we are adding an include for `linux/unicode.h', include it
in `fs/ksmbd/connection.h' as well since it should be explicit there.

Signed-off-by: default avatarAtte Heikkilä <atteh.mailbox@gmail.com>
Acked-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 7c88c1e0

fs/ksmbd/connection.h

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <net/request_sock.h>

#include <linux/kthread.h>

#include <linux/nls.h>

#include <linux/unicode.h>



#include "smb_common.h"

#include "ksmbd_work.h"

fs/ksmbd/vfs.c

+17 −3
Original line number Diff line number Diff line
@@ -1145,12 +1145,23 @@ static int __caseless_lookup(struct dir_context *ctx, const char *name, 
			     unsigned int d_type)

{

	struct ksmbd_readdir_data *buf;

	int cmp = -EINVAL;



	buf = container_of(ctx, struct ksmbd_readdir_data, ctx);



	if (buf->used != namlen)

		return 0;

	if (!strncasecmp((char *)buf->private, name, namlen)) {

	if (IS_ENABLED(CONFIG_UNICODE) && buf->um) {

		const struct qstr q_buf = {.name = buf->private,

					   .len = buf->used};

		const struct qstr q_name = {.name = name,

					    .len = namlen};



		cmp = utf8_strncasecmp(buf->um, &q_buf, &q_name);

	}

	if (cmp < 0)

		cmp = strncasecmp((char *)buf->private, name, namlen);

	if (!cmp) {

		memcpy((char *)buf->private, name, namlen);

		buf->dirent_count = 1;

		return -EEXIST;
@@ -1166,7 +1177,8 @@ static int __caseless_lookup(struct dir_context *ctx, const char *name, 
 *

 * Return:	0 on success, otherwise error

 */

static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name, size_t namelen)

static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name,

				   size_t namelen, struct unicode_map *um)

{

	int ret;

	struct file *dfilp;
@@ -1176,6 +1188,7 @@ static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name, size_t na 
		.private	= name,

		.used		= namelen,

		.dirent_count	= 0,

		.um		= um,

	};



	dfilp = dentry_open(dir, flags, current_cred());
@@ -1238,7 +1251,8 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name, 
				break;



			err = ksmbd_vfs_lookup_in_dir(&parent, filename,

						      filename_len);

						      filename_len,

						      work->conn->um);

			path_put(&parent);

			if (err)

				goto out;

fs/ksmbd/vfs.h

+2 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <linux/namei.h>

#include <uapi/linux/xattr.h>

#include <linux/posix_acl.h>

#include <linux/unicode.h>



#include "smbacl.h"

#include "xattr.h"
@@ -60,6 +61,7 @@ struct ksmbd_readdir_data { 
	unsigned int		used;

	unsigned int		dirent_count;

	unsigned int		file_attr;

	struct unicode_map	*um;

};



/* ksmbd kstat wrapper to get valid create time when reading dir entry */