The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

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: [PATCH] erofs: add unsupported inode i_format check

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

diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h index 9ad1615f4474..e8d04d808fa6 100644 --- a/fs/erofs/erofs_fs.h +++ b/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 */ diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index 119fdce1b520..7ed2d7391692 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",