Re: [PATCH v5 1/3] tty: fix data race in flush_to_ldisc

[Peter Hurley]

On Thu, Sep 17, 2015 at 11:17 AM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> flush_to_ldisc reads port->itty and checks that it is not NULL,
> concurrently release_tty sets port->itty to NULL. It is possible
> that flush_to_ldisc loads port->itty once, ensures that it is
> not NULL, but then reloads it again and uses. The second load
> can already return NULL, which will cause a crash.
>
> Use READ_ONCE to read port->itty.
>
> The data race was found with KernelThreadSanitizer (KTSAN).

Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
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