cifs: Fix getting DACL-only xattr system.cifs_acl and system.smb3_acl

Currently ->get_acl() callback always create request for OWNER, GROUP and
DACL, even when only DACLs was requested by user. Change API callback to
request only information for which the caller asked. Therefore when only
DACLs requested, then SMB client will prepare and send DACL-only request.

This change fixes retrieving of "system.cifs_acl" and "system.smb3_acl"
xattrs to contain only DACL structure as documented.

Note that setting/changing of "system.cifs_acl" and "system.smb3_acl"
xattrs already takes only DACL structure and ignores all other fields.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: pali

fs/smb/client/cifsacl.c

@@ -1550,7 +1550,7 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 	int rc = 0;
 	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
 	struct smb_version_operations *ops;
-	const u32 info = 0;
+	const u32 info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO;
 
 	cifs_dbg(NOISY, "converting ACL to mode for %s\n", path);
 
@@ -1604,7 +1604,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 	struct tcon_link *tlink;
 	struct smb_version_operations *ops;
 	bool mode_from_sid, id_from_sid;
-	const u32 info = 0;
+	const u32 info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO;
 	bool posix;
 
 	tlink = cifs_sb_tlink(cifs_sb);

fs/smb/client/cifssmb.c

@@ -3403,8 +3403,7 @@ CIFSSMBGetCIFSACL(const unsigned int xid, struct cifs_tcon *tcon, __u16 fid,
 	/* BB TEST with big acls that might need to be e.g. larger than 16K */
 	pSMB->MaxSetupCount = 0;
 	pSMB->Fid = fid; /* file handle always le */
-	pSMB->AclFlags = cpu_to_le32(CIFS_ACL_OWNER | CIFS_ACL_GROUP |
-				     CIFS_ACL_DACL | info);
+	pSMB->AclFlags = cpu_to_le32(info);
 	pSMB->ByteCount = cpu_to_le16(11); /* 3 bytes pad + 8 bytes parm */
 	inc_rfc1001_len(pSMB, 11);
 	iov[0].iov_base = (char *)pSMB;

fs/smb/client/smb2pdu.c

@@ -3916,12 +3916,10 @@ SMB2_query_acl(const unsigned int xid, struct cifs_tcon *tcon,
 	       u64 persistent_fid, u64 volatile_fid,
 	       void **data, u32 *plen, u32 extra_info)
 {
-	__u32 additional_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO |
-				extra_info;
 	*plen = 0;
 
 	return query_info(xid, tcon, persistent_fid, volatile_fid,
-			  0, SMB2_O_INFO_SECURITY, additional_info,
+			  0, SMB2_O_INFO_SECURITY, extra_info,
 			  SMB2_MAX_BUFFER_SIZE, MIN_SEC_DESC_LEN, data, plen);
 }
 

fs/smb/client/xattr.c

@@ -320,10 +320,17 @@ static int cifs_xattr_get(const struct xattr_handler *handler,
 		if (pTcon->ses->server->ops->get_acl == NULL)
 			goto out; /* rc already EOPNOTSUPP */
 
-		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
-			extra_info = SACL_SECINFO;
-		} else {
-			extra_info = 0;
+		switch (handler->flags) {
+		case XATTR_CIFS_NTSD_FULL:
+			extra_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO | SACL_SECINFO;
+			break;
+		case XATTR_CIFS_NTSD:
+			extra_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO;
+			break;
+		case XATTR_CIFS_ACL:
+		default:
+			extra_info = DACL_SECINFO;
+			break;
 		}
 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
 				inode, full_path, &acllen, extra_info);