From: Gao Xiang <hsiangkao@redhat.com>
Date: Mon, 29 Mar 2021 00:36:14 +0000 (+0800)
Subject: erofs: add unsupported inode i_format check
X-Git-Tag: v4.19.191~407
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=006270aa8f9c32c8fc723b0b2874b91fd10c1290;p=thirdparty%2Fkernel%2Fstable.git

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>
---

diff --git a/drivers/staging/erofs/erofs_fs.h b/drivers/staging/erofs/erofs_fs.h
index 7677da889f125..d8838ce669416 100644
--- 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;
 
diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
index a43abd530cc10..02398c7eb4a40 100644
--- a/drivers/staging/erofs/inode.c
+++ b/drivers/staging/erofs/inode.c
@@ -48,6 +48,12 @@ static struct page *read_inode(struct inode *inode, unsigned int *ofs)
 	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",