On Wed, Aug 03, 2016 at 03:36:44PM +0800, Eryu Guan wrote:

On Mon, Jul 25, 2016 at 01:56:28PM -0700, Greg Kroah-Hartman wrote:

quoted

4.4-stable review patch.  If anyone has any objections, please let me know.

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From: Vivek Goyal <vgoyal@redhat.com>

commit 07a2daab49c549a37b5b744cbebb6e3f445f12bc upstream.

Right now when a new overlay inode is created, we initialize overlay
inode's ->i_mode from underlying inode ->i_mode but we retain only
file type bits (S_IFMT) and discard permission bits.

This patch changes it and retains permission bits too. This should allow
overlay to do permission checks on overlay inode itself in task context.

[SzM] It also fixes clearing suid/sgid bits on write.

This patch introduced a hang when writing to suid file, fstests
generic/355 could reproduce the hang easily, it only failed the test
without this patch and didn't hang the kernel.

Should we skip it for now and wait for a further fix?

Does Linus's tree have the same problem?

(The 4.6-stable tree faces the same question)

Are we just missing a patch to be applied here?

And this is already in the released stable kernels...

thanks,

greg k-h