linux-kernel - Re: [PATCH 5.10 000/163] 5.10.119-rc1 review

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220527223833.GA3166370@roeck-us.net>
Date:   Fri, 27 May 2022 15:38:33 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     "Jason A. Donenfeld" <Jason@...c4.com>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Pavel Machek <pavel@...x.de>, Chris.Paterson2@...esas.com,
        linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
        shuah@...nel.org, patches@...nelci.org,
        lkft-triage@...ts.linaro.org, jonathanh@...dia.com,
        f.fainelli@...il.com, sudipm.mukherjee@...il.com,
        slade@...dewatkins.com
Subject: Re: [PATCH 5.10 000/163] 5.10.119-rc1 review

On Fri, May 27, 2022 at 11:10:35PM +0200, Jason A. Donenfeld wrote:
> Hi Guenter,
> 
> On Fri, May 27, 2022 at 09:59:14AM -0700, Guenter Roeck wrote:
> > Given that we (ChromeOS) have been hit by rng related
> > issues before (specifically boot stalls on some hardware), I am quite
> > concerned about the possible impact of this series for stable releases.
> 
> The urandom try_to_generate_entropy() change from 5.18 wasn't backported.
> 

Was it not backported on purpose or is it missing ?

Thanks,
Guenter

> zx2c4@...nkpad ~/Projects/random-linux $ git diff linux-5.10.y:drivers/char/random.c master:drivers/char/random.c
> [...snip...]
> @@ -1292,6 +1311,13 @@ static ssize_t urandom_read_iter(struct kiocb *kiocb, struct iov_iter *iter)
>  {
>         static int maxwarn = 10;
> 
> +       /*
> +        * Opportunistically attempt to initialize the RNG on platforms that
> +        * have fast cycle counters, but don't (for now) require it to succeed.
> +        */
> +       if (!crng_ready())
> +               try_to_generate_entropy();
> +
>         if (!crng_ready()) {
>                 if (!ratelimit_disable && maxwarn <= 0)
>                         ++urandom_warning.missed;
> 
> 
> 
> Jason