Commit a2809d0e authored by Eugene Korenevsky's avatar Eugene Korenevsky Committed by Steve French
Browse files

cifs: quirk for STATUS_OBJECT_NAME_INVALID returned for non-ASCII dfs refs 

Windows SMB server responds with STATUS_OBJECT_NAME_INVALID code to
SMB2 QUERY_INFO request for "\<server>\<dfsname>\<linkpath>" DFS reference,
where <dfsname> contains non-ASCII unicode symbols.

Check such DFS reference and emulate -EREMOTE if it is actual.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215440


Signed-off-by: default avatarEugene Korenevsky <ekorenevsky@astralinux.ru>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 7eacba3b

fs/cifs/cifsproto.h

+5 −0
Original line number Diff line number Diff line
@@ -647,6 +647,11 @@ static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses, 
int match_target_ip(struct TCP_Server_Info *server,

		    const char *share, size_t share_len,

		    bool *result);



int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid,

				       struct cifs_tcon *tcon,

				       struct cifs_sb_info *cifs_sb,

				       const char *dfs_link_path);

#endif



static inline int cifs_create_options(struct cifs_sb_info *cifs_sb, int options)

fs/cifs/connect.c

+5 −0
Original line number Diff line number Diff line
@@ -3374,6 +3374,11 @@ static int is_path_remote(struct mount_ctx *mnt_ctx) 


	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,

					     full_path);

#ifdef CONFIG_CIFS_DFS_UPCALL

	if (rc == -ENOENT && is_tcon_dfs(tcon))

		rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,

							full_path);

#endif

	if (rc != 0 && rc != -EREMOTE) {

		kfree(full_path);

		return rc;

fs/cifs/inode.c

+6 −0
Original line number Diff line number Diff line
@@ -952,6 +952,12 @@ cifs_get_inode_info(struct inode **inode, 
		rc = server->ops->query_path_info(xid, tcon, cifs_sb,

						 full_path, tmp_data,

						 &adjust_tz, &is_reparse_point);

#ifdef CONFIG_CIFS_DFS_UPCALL

		if (rc == -ENOENT && is_tcon_dfs(tcon))

			rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon,

								cifs_sb,

								full_path);

#endif

		data = tmp_data;

	}

fs/cifs/misc.c

+49 −0
Original line number Diff line number Diff line
@@ -1302,4 +1302,53 @@ int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) 
	cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;

	return 0;

}



/** cifs_dfs_query_info_nonascii_quirk

 * Handle weird Windows SMB server behaviour. It responds with

 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request

 * for "\<server>\<dfsname>\<linkpath>" DFS reference,

 * where <dfsname> contains non-ASCII unicode symbols.

 *

 * Check such DFS reference and emulate -ENOENT if it is actual.

 */

int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid,

				       struct cifs_tcon *tcon,

				       struct cifs_sb_info *cifs_sb,

				       const char *linkpath)

{

	char *treename, *dfspath, sep;

	int treenamelen, linkpathlen, rc;



	treename = tcon->treeName;

	/* MS-DFSC: All paths in REQ_GET_DFS_REFERRAL and RESP_GET_DFS_REFERRAL

	 * messages MUST be encoded with exactly one leading backslash, not two

	 * leading backslashes.

	 */

	sep = CIFS_DIR_SEP(cifs_sb);

	if (treename[0] == sep && treename[1] == sep)

		treename++;

	linkpathlen = strlen(linkpath);

	treenamelen = strnlen(treename, MAX_TREE_SIZE + 1);

	dfspath = kzalloc(treenamelen + linkpathlen + 1, GFP_KERNEL);

	if (!dfspath)

		return -ENOMEM;

	if (treenamelen)

		memcpy(dfspath, treename, treenamelen);

	memcpy(dfspath + treenamelen, linkpath, linkpathlen);

	rc = dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls,

			    cifs_remap(cifs_sb), dfspath, NULL, NULL);

	if (rc == 0) {

		cifs_dbg(FYI, "DFS ref '%s' is found, emulate -EREMOTE\n",

			 dfspath);

		rc = -EREMOTE;

	} else if (rc == -EEXIST) {

		cifs_dbg(FYI, "DFS ref '%s' is not found, emulate -ENOENT\n",

			 dfspath);

		rc = -ENOENT;

	} else {

		cifs_dbg(FYI, "%s: dfs_cache_find returned %d\n", __func__, rc);

	}

	kfree(dfspath);

	return rc;

}

#endif