ksmbd: set MAY_* flags together with open flags

mainline inclusion
from mainline-v5.15-rc1
commit 6c5e36d1
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I60T7G
CVE: NA

Reference: https://git.kernel.org/torvalds/linux/c/6c5e36d13e2a

set MAY_* flags together with open flags and
remove ksmbd_vfs_inode_permission().
Signed-off-by: NHyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZhong Jinghua <zhongjinghua@huawei.com>

fs/ksmbd/smb2pdu.c

@@ -1836,21 +1836,27 @@ int smb2_tree_connect(struct ksmbd_work *work)
  * @file_present:	is file already present
  * @access:		file access flags
  * @disposition:	file disposition flags
+ * @may_flags:		set with MAY_ flags
  *
  * Return:      file open flags
  */
 static int smb2_create_open_flags(bool file_present, __le32 access,
-				  __le32 disposition)
+				  __le32 disposition,
+				  int *may_flags)
 {
 	int oflags = O_NONBLOCK | O_LARGEFILE;
 
 	if (access & FILE_READ_DESIRED_ACCESS_LE &&
-	    access & FILE_WRITE_DESIRE_ACCESS_LE)
+	    access & FILE_WRITE_DESIRE_ACCESS_LE) {
 		oflags |= O_RDWR;
-	else if (access & FILE_WRITE_DESIRE_ACCESS_LE)
+		*may_flags = MAY_OPEN | MAY_READ | MAY_WRITE;
+	} else if (access & FILE_WRITE_DESIRE_ACCESS_LE) {
 		oflags |= O_WRONLY;
-	else
+		*may_flags = MAY_OPEN | MAY_WRITE;
+	} else {
 		oflags |= O_RDONLY;
+		*may_flags = MAY_OPEN | MAY_READ;
+	}
 
 	if (access == FILE_READ_ATTRIBUTES_LE)
 		oflags |= O_PATH;
@@ -1884,6 +1890,7 @@ static int smb2_create_open_flags(bool file_present, __le32 access,
 			break;
 		}
 	}
+
 	return oflags;
 }
 
@@ -2355,7 +2362,7 @@ int smb2_open(struct ksmbd_work *work)
 	struct create_ea_buf_req *ea_buf = NULL;
 	struct oplock_info *opinfo;
 	__le32 *next_ptr = NULL;
-	int req_op_level = 0, open_flags = 0, file_info = 0;
+	int req_op_level = 0, open_flags = 0, may_flags = 0, file_info = 0;
 	int rc = 0, len = 0;
 	int contxt_cnt = 0, query_disk_id = 0;
 	int maximal_access_ctxt = 0, posix_ctxt = 0;
@@ -2696,7 +2703,8 @@ int smb2_open(struct ksmbd_work *work)
 	}
 
 	open_flags = smb2_create_open_flags(file_present, daccess,
-					    req->CreateDisposition);
+					    req->CreateDisposition,
+					    &may_flags);
 
 	if (!test_tree_conn_flag(tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) {
 		if (open_flags & O_CREAT) {
@@ -2723,21 +2731,23 @@ int smb2_open(struct ksmbd_work *work)
 				goto err_out;
 		}
 	} else if (!already_permitted) {
-		bool may_delete;
-
-		may_delete = daccess & FILE_DELETE_LE ||
-			req->CreateOptions & FILE_DELETE_ON_CLOSE_LE;
-
 		/* FILE_READ_ATTRIBUTE is allowed without inode_permission,
 		 * because execute(search) permission on a parent directory,
 		 * is already granted.
 		 */
 		if (daccess & ~(FILE_READ_ATTRIBUTES_LE | FILE_READ_CONTROL_LE)) {
-			rc = ksmbd_vfs_inode_permission(path.dentry,
-							open_flags & O_ACCMODE,
-							may_delete);
+			rc = inode_permission(&init_user_ns,
+					      d_inode(path.dentry),
+					      may_flags);
 			if (rc)
 				goto err_out;
+
+			if ((daccess & FILE_DELETE_LE) ||
+			    (req->CreateOptions & FILE_DELETE_ON_CLOSE_LE)) {
+				rc = ksmbd_vfs_may_delete(path.dentry);
+				if (rc)
+					goto err_out;
+			}
 		}
 	}
 

fs/ksmbd/vfs.c

@@ -95,39 +95,23 @@ static int ksmbd_vfs_lock_parent(struct dentry *parent, struct dentry *child)
 	return ret;
 }
 
-int ksmbd_vfs_inode_permission(struct dentry *dentry, int acc_mode, bool delete)
+int ksmbd_vfs_may_delete(struct dentry *dentry)
 {
-	int mask, ret = 0;
-
-	mask = 0;
-	acc_mode &= O_ACCMODE;
-
-	if (acc_mode == O_RDONLY)
-		mask = MAY_READ;
-	else if (acc_mode == O_WRONLY)
-		mask = MAY_WRITE;
-	else if (acc_mode == O_RDWR)
-		mask = MAY_READ | MAY_WRITE;
-
-	if (inode_permission(&init_user_ns, d_inode(dentry), mask | MAY_OPEN))
-		return -EACCES;
-
-	if (delete) {
-		struct dentry *parent;
-
-		parent = dget_parent(dentry);
-		ret = ksmbd_vfs_lock_parent(parent, dentry);
-		if (ret) {
-			dput(parent);
-			return ret;
-		}
-
-		if (inode_permission(&init_user_ns, d_inode(parent), MAY_EXEC | MAY_WRITE))
-			ret = -EACCES;
+	struct dentry *parent;
+	int ret;
 
-		inode_unlock(d_inode(parent));
+	parent = dget_parent(dentry);
+	ret = ksmbd_vfs_lock_parent(parent, dentry);
+	if (ret) {
 		dput(parent);
+		return ret;
 	}
+
+	ret = inode_permission(&init_user_ns, d_inode(parent),
+			       MAY_EXEC | MAY_WRITE);
+
+	inode_unlock(d_inode(parent));
+	dput(parent);
 	return ret;
 }
 

fs/ksmbd/vfs.h

@@ -192,8 +192,7 @@ struct ksmbd_kstat {
 	__le32			file_attributes;
 };
 
-int ksmbd_vfs_inode_permission(struct dentry *dentry, int acc_mode,
-			       bool delete);
+int ksmbd_vfs_may_delete(struct dentry *dentry);
 int ksmbd_vfs_query_maximal_access(struct dentry *dentry, __le32 *daccess);
 int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode);
 int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode);