erofs: add unsupported inode i_format check

stable inclusion
from stable-5.10.36
commit dbaf435ddf973cc90146c95e526bd6163843377b
bugzilla: 51867
CVE: NA

--------------------------------

commit 24a806d8 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: 431339ba ("staging: erofs: add inode operations")
Cc: <stable@vger.kernel.org> # 4.19+
Signed-off-by: NGao Xiang <hsiangkao@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/erofs/erofs_fs.h

@@ -75,6 +75,9 @@ 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 */

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",