Re: [stable] locks: fix a potential use-after-free problem when wakeup a waiter

Greg Kroah-Hartman
2020-03-19T06:37:45Z

On Wed, Mar 18, 2020 at 06:29:06PM -0400, Sasha Levin wrote:
> On Wed, Mar 18, 2020 at 10:09:20PM +0000, Ben Hutchings wrote:
> > This commit (included in 5.6-rc5) seems to be needed for 5.4 and 5.5
> > branches:
> >
> > commit 6d390e4b5d48ec03bb87e63cf0a2bff5f4e116da
> > Author: yangerkun <yangerkun@huawei.com>
> > Date: Wed Mar 4 15:25:56 2020 +0800
> >
> > locks: fix a potential use-after-free problem when wakeup a waiter
>
> I've queued it up for 5.5 and 5.4, thanks!
>
> > I'm a bit surprised that it hasn't yet been applied, while some fixes
> > from 5.6-rc6 have.
>
> Greg, I wonder if it makes sense to have you push a "Greg is here
> --->" "bookmark" in the form of a tag/branch on linux-stable-rc.git? at
> the very least it'll make it easy to see if something was missed or
> still waiting in the queue.

To quote Jeff Layton:

Hi Greg, there is a performance regression with this patch. We're
sorting through potential ways to address it at the moment, but you may
want to hold off until we have a fix for that merged.

Sorry for the hassle!

Which is why I dropped it for now.

I'll go drop it again :)

thanks,

greg k-h