ubifs: xattr: Fix some potential memory leaks while iterating entries

Fix some potential memory leaks in error handling branches while
iterating xattr entries. For example, function ubifs_tnc_remove_ino()
forgets to free pxent if it exists. Similar problems also exist in
ubifs_purge_xattrs(), ubifs_add_orphan() and ubifs_jnl_write_inode().
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Cc: <stable@vger.kernel.org>
Fixes: 1e51764a ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/journal.c

@@ -894,6 +894,7 @@ int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode)
 				if (err == -ENOENT)
 					break;
 
+				kfree(pxent);
 				goto out_release;
 			}
 
@@ -906,6 +907,7 @@ int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode)
 				ubifs_err(c, "dead directory entry '%s', error %d",
 					  xent->name, err);
 				ubifs_ro_mode(c, err);
+				kfree(pxent);
 				kfree(xent);
 				goto out_release;
 			}

fs/ubifs/orphan.c

@@ -173,6 +173,7 @@ int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
 			err = PTR_ERR(xent);
 			if (err == -ENOENT)
 				break;
+			kfree(pxent);
 			return err;
 		}
 
@@ -182,6 +183,7 @@ int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
 
 		xattr_orphan = orphan_add(c, xattr_inum, orphan);
 		if (IS_ERR(xattr_orphan)) {
+			kfree(pxent);
 			kfree(xent);
 			return PTR_ERR(xattr_orphan);
 		}

fs/ubifs/tnc.c

@@ -2885,6 +2885,7 @@ int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
 			err = PTR_ERR(xent);
 			if (err == -ENOENT)
 				break;
+			kfree(pxent);
 			return err;
 		}
 
@@ -2898,6 +2899,7 @@ int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
 		fname_len(&nm) = le16_to_cpu(xent->nlen);
 		err = ubifs_tnc_remove_nm(c, &key1, &nm);
 		if (err) {
+			kfree(pxent);
 			kfree(xent);
 			return err;
 		}
@@ -2906,6 +2908,7 @@ int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
 		highest_ino_key(c, &key2, xattr_inum);
 		err = ubifs_tnc_remove_range(c, &key1, &key2);
 		if (err) {
+			kfree(pxent);
 			kfree(xent);
 			return err;
 		}

fs/ubifs/xattr.c

@@ -522,6 +522,7 @@ int ubifs_purge_xattrs(struct inode *host)
 				  xent->name, err);
 			ubifs_ro_mode(c, err);
 			kfree(pxent);
+			kfree(xent);
 			return err;
 		}
 
@@ -531,6 +532,7 @@ int ubifs_purge_xattrs(struct inode *host)
 		err = remove_xattr(c, host, xino, &nm);
 		if (err) {
 			kfree(pxent);
+			kfree(xent);
 			iput(xino);
 			ubifs_err(c, "cannot remove xattr, error %d", err);
 			return err;