From f8431d32bcd261e10624147b5d2a19b3dcc8bcf7 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Mon, 15 Mar 2021 17:47:46 +0800
Subject: [PATCH] ovl: do not fail because of O_NOATIME
mainline inclusion
from mainline-v5.11-rc1
commit b6650dab404c701d7fe08a108b746542a934da84
category: bugfix
bugzilla: NA
CVE: CVE-2020-16120
--------------------------------
In case the file cannot be opened with O_NOATIME because of lack of
capabilities, then clear O_NOATIME instead of failing.
Remove WARN_ON(), since it would now trigger if O_NOATIME was cleared.
Noticed by Amir Goldstein.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
---
fs/overlayfs/file.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index f464a23c95af..cd1c94f77dee 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -45,9 +45,10 @@ static struct file *ovl_open_realfile(const struct file *file,
err = inode_permission(realinode, MAY_OPEN | acc_mode);
if (err) {
realfile = ERR_PTR(err);
- } else if (!inode_owner_or_capable(realinode)) {
- realfile = ERR_PTR(-EPERM);
} else {
+ if (!inode_owner_or_capable(realinode))
+ flags &= ~O_NOATIME;
+
realfile = open_with_fake_path(&file->f_path, flags, realinode,
current_cred());
}
@@ -67,12 +68,6 @@ static int ovl_change_flags(struct file *file, unsigned int flags)
struct inode *inode = file_inode(file);
int err;
- flags |= OVL_OPEN_FLAGS;
-
- /* If some flag changed that cannot be changed then something's amiss */
- if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK))
- return -EIO;
-
flags &= OVL_SETFL_MASK;
if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode))
--
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