From: Miklos Szeredi mszeredi@redhat.com
mainline inclusion from mainline-v5.11-rc1 commit b6650dab404c701d7fe08a108b746542a934da84 category: bugfix bugzilla: NA CVE: CVE-2020-16120
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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))