linux-kernel - Re: [PATCH v10 3/4] random: introduce generic vDSO getrandom() implementation

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: <878rjs7mcx.fsf@oldenburg.str.redhat.com>
Date:   Wed, 30 Nov 2022 11:44:30 +0100
From:   Florian Weimer <fweimer@...hat.com>
To:     "Jason A. Donenfeld" <Jason@...c4.com>
Cc:     linux-kernel@...r.kernel.org, patches@...ts.linux.dev,
        tglx@...utronix.de, linux-crypto@...r.kernel.org,
        linux-api@...r.kernel.org, x86@...nel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Adhemerval Zanella Netto <adhemerval.zanella@...aro.org>,
        Carlos O'Donell <carlos@...hat.com>,
        Arnd Bergmann <arnd@...db.de>,
        Christian Brauner <brauner@...nel.org>
Subject: Re: [PATCH v10 3/4] random: introduce generic vDSO getrandom()
 implementation

* Jason A. Donenfeld:

> diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
> index 73eb622e7663..9ae4d76b36c7 100644
> --- a/include/vdso/datapage.h
> +++ b/include/vdso/datapage.h
> @@ -109,6 +109,16 @@ struct vdso_data {
>  	struct arch_vdso_data	arch_data;
>  };
>  
> +/**
> + * struct vdso_rng_data - vdso RNG state information
> + * @generation:	a counter representing the number of RNG reseeds
> + * @is_ready:	whether the RNG is initialized
> + */
> +struct vdso_rng_data {
> +	unsigned long	generation;
> +	bool		is_ready;
> +};
> +

I don't think you can use a type like long here.  The header says this:

 * vdso_data will be accessed by 64 bit and compat code at the same time
 * so we should be careful before modifying this structure.

So the ABI must be same for 32-bit and 64-bit mode, and long isn't.

Thanks,
Florian