--- /dev/null
+From 24a806d849c0b0c1d0cd6a6b93ba4ae4c0ec9f08 Mon Sep 17 00:00:00 2001
+From: Gao Xiang <hsiangkao@redhat.com>
+Date: Mon, 29 Mar 2021 08:36:14 +0800
+Subject: erofs: add unsupported inode i_format check
+
+From: Gao Xiang <hsiangkao@redhat.com>
+
+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>
+
+---
+ drivers/staging/erofs/erofs_fs.h | 3 +++
+ drivers/staging/erofs/inode.c | 6 ++++++
+ 2 files changed, 9 insertions(+)
+
+--- a/drivers/staging/erofs/erofs_fs.h
++++ b/drivers/staging/erofs/erofs_fs.h
+@@ -71,6 +71,9 @@ enum {
+ #define EROFS_I_VERSION_BIT 0
+ __EROFS_BIT(EROFS_I_, DATA_MAPPING, VERSION);
+
++#define EROFS_I_ALL \
++ ((1 << (EROFS_I_DATA_MAPPING_BIT + EROFS_I_DATA_MAPPING_BITS)) - 1)
++
+ struct erofs_inode_v1 {
+ /* 0 */__le16 i_advise;
+
+--- a/drivers/staging/erofs/inode.c
++++ b/drivers/staging/erofs/inode.c
+@@ -48,6 +48,12 @@ static struct page *read_inode(struct in
+ v1 = page_address(page) + *ofs;
+ ifmt = le16_to_cpu(v1->i_advise);
+
++ if (ifmt & ~EROFS_I_ALL) {
++ errln("unsupported i_format %u of nid %llu", ifmt, vi->nid);
++ err = -EOPNOTSUPP;
++ goto err_out;
++ }
++
+ vi->data_mapping_mode = __inode_data_mapping(ifmt);
+ if (unlikely(vi->data_mapping_mode >= EROFS_INODE_LAYOUT_MAX)) {
+ errln("unknown data mapping mode %u of nid %llu",