From a70bc7cc7608cc7bfa130c2fd982f6e7760e682b Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Sun, 1 Dec 2019 16:01:09 +0800 Subject: [PATCH] erofs: zero out when listxattr is called with no xattr commit 926d1650176448d7684b991fbe1a5b1a8289e97c upstream. As David reported [1], ENODATA returns when attempting to modify files by using EROFS as an overlayfs lower layer. The root cause is that listxattr could return unexpected -ENODATA by mistake for inodes without xattr. That breaks listxattr return value convention and it can cause copy up failure when used with overlayfs. Resolve by zeroing out if no xattr is found for listxattr. [1] https://lore.kernel.org/r/CAEvUa7nxnby+rxK-KRMA46=exeOMApkDMAV08AjMkkPnTPV4CQ@mail.gmail.com Link: https://lore.kernel.org/r/20191201084040.29275-1-hsiangkao@aol.com Fixes: cadf1ccf1b00 ("staging: erofs: add error handling for xattr submodule") Cc: # 4.19+ Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Signed-off-by: Greg Kroah-Hartman --- fs/erofs/xattr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index a13a78725c57..b766c3ee5fa8 100644 --- a/fs/erofs/xattr.c +++ b/fs/erofs/xattr.c @@ -649,6 +649,8 @@ ssize_t erofs_listxattr(struct dentry *dentry, struct listxattr_iter it; ret = init_inode_xattrs(d_inode(dentry)); + if (ret == -ENOATTR) + return 0; if (ret) return ret;