Re: [PATCH] ovl: useing ovl_revert_creds() instead of revert_creds(),

On Wed, 19 May 2021 at 05:29, Yao Haidong [off-list ref] wrote:

Miklos Szeredi [off-list ref] 于2021年5月18日周二 下午9:41写道：

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On Tue, 18 May 2021 at 14:21, Haidong Yao [off-list ref] wrote:

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From: Haidong Yao <redacted>

[...]

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diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 4d53d3b7e5fe..d9bc658f22ee 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c

@@ -60,7 +60,7 @@ static struct file *ovl_open_realfile(const struct file *file,
                realfile = open_with_fake_path(&file->f_path, flags, realinode,
                                               current_cred());
        }
-       revert_creds(old_cred);
+       ovl_revert_creds(inode->i_sb, old_cred);

Upstream kernel doesn't have ovl_revert_creds().

Hi Miklos:

Sorry,
Sometimes，old_cred is NULL.
Do you think this is a problem?
Can I add ovl_revert_creds()? or You have a better way?

old_cred can't be NULL on upstream (Linus) kernel.

From the taint flags I can see that this is some weird setup.  Please
contact the distro that is providing the kerne/modules about this
issue.  It's not anything the upstream kernel maintainers can help
with.

Thanks,
Miklos