Re: [PATCH] infiniband: fix a subtle race condition

From: Cong Wang
Date: Thu Jun 14 2018 - 13:03:35 EST

On Thu, Jun 14, 2018 at 7:24 AM, Jason Gunthorpe <jgg@xxxxxxxxxxxx> wrote:
> This was my brief reaction too, this code path almost certainly has a
> use-after-free, and we should fix the concurrency between the two
> places in some correct way..

First of all, why use-after-free could trigger an imbalance unlock?
IOW, why do we have to solve use-after-free to fix this imbalance

Second of all, my patch is _not_ intended to solve any use-after-free,
it only solves the imbalance unlock. I never claim it solves more

Third of all, the use-after-free I can see (race with ->close) exists
before my patch, this patch doesn't make it better or worse, nor
I have any intend to fix it.