From c57af0be7722a2c896af76a985200930c95428bf Mon Sep 17 00:00:00 2001
From: Gao Xiang <hsiangkao@redhat.com>
Date: Mon, 29 Mar 2021 08:36:14 +0800
Subject: [PATCH] erofs: add unsupported inode i_format check
commit 24a806d849c0b0c1d0cd6a6b93ba4ae4c0ec9f08 upstream.
If any unknown i_format fields are set (may be of some new incompat
inode features), mark such inode as unsupported.
Just in case of any new incompat i_format fields added in the future.
Link: https://lore.kernel.org/r/20210329003614.6583-1-hsiangkao@aol.com
Fixes: 431339ba9042 ("staging: erofs: add inode operations")
Cc: <stable@vger.kernel.org> # 4.19+
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/erofs/erofs_fs.h | 3 +++
fs/erofs/inode.c | 7 +++++++
2 files changed, 10 insertions(+)
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index b1ee5654750d..52ab96154467 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -74,6 +74,9 @@ static inline bool erofs_inode_is_data_compressed(unsigned int datamode)
#define EROFS_I_VERSION_BIT 0
#define EROFS_I_DATALAYOUT_BIT 1
+#define EROFS_I_ALL \
+ ((1 << (EROFS_I_DATALAYOUT_BIT + EROFS_I_DATALAYOUT_BITS)) - 1)
+
/* 32-byte reduced form of an ondisk inode */
struct erofs_inode_compact {
__le16 i_format; /* inode format hints */
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 70fd3af7b8cb..0dbeaf68e1d6 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -44,6 +44,13 @@ static struct page *erofs_read_inode(struct inode *inode,
dic = page_address(page) + *ofs;
ifmt = le16_to_cpu(dic->i_format);
+ if (ifmt & ~EROFS_I_ALL) {
+ erofs_err(inode->i_sb, "unsupported i_format %u of nid %llu",
+ ifmt, vi->nid);
+ err = -EOPNOTSUPP;
+ goto err_out;
+ }
+
vi->datalayout = erofs_inode_datalayout(ifmt);
if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
erofs_err(inode->i_sb, "unsupported datalayout %u of nid %llu",