From: Borislav Petkov <bp@alien8.de>
To: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: linux-kernel@vger.kernel.org, H Peter Anvin <hpa@zytor.com>
Subject: Re: [PATCH 8/8] x86, microcode, intel: defend apply_microcode_intel with BUG_ON
Date: Fri, 7 Nov 2014 21:05:01 +0100 [thread overview]
Message-ID: <20141107200501.GF5180@pd.tnic> (raw)
In-Reply-To: <1410197875-19252-9-git-send-email-hmh@hmh.eng.br>
On Mon, Sep 08, 2014 at 02:37:54PM -0300, Henrique de Moraes Holschuh wrote:
> Microcode updates that requires an unknown loader should never reach the
> apply_* functions (the code should have rejected it earlier). Likewise
> for an unknown microcode header layout.
>
> Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
> ---
> arch/x86/kernel/cpu/microcode/intel.c | 2 ++
> arch/x86/kernel/cpu/microcode/intel_early.c | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
> index 40caef1..439681f 100644
> --- a/arch/x86/kernel/cpu/microcode/intel.c
> +++ b/arch/x86/kernel/cpu/microcode/intel.c
> @@ -157,6 +157,8 @@ static int apply_microcode_intel(int cpu)
> if (mc_intel == NULL)
> return 0;
>
> + BUG_ON(mc_intel->hdr.hdrver != 1 || mc_intel->hdr.ldrver != 1);
> +
> /* Intel SDM vol 3A section 9.11.6, page 9-34 */
> if (WARN_ONCE((unsigned long)(mc_intel->bits) % 16,
> "microcode data incorrectly aligned"))
> diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c
> index 994c59b..095db11 100644
> --- a/arch/x86/kernel/cpu/microcode/intel_early.c
> +++ b/arch/x86/kernel/cpu/microcode/intel_early.c
> @@ -671,6 +671,8 @@ static int apply_microcode_early(struct mc_saved_data *mc_saved_data,
> if (mc_intel == NULL)
> return 0;
>
> + BUG_ON(mc_intel->hdr.hdrver != 1 || mc_intel->hdr.ldrver != 1);
> +
> mcu_data = mc_intel->bits;
> aligned_mcu_data = mc_intel->bits;
Both not needed, because we're running all microcode through
microcode_sanity_check() first which already does that check.
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
--
next prev parent reply other threads:[~2014-11-07 20:05 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-08 17:37 [PATCH 0/8] x86, microcode, intel: fixes and enhancements Henrique de Moraes Holschuh
2014-09-08 17:37 ` [PATCH 1/8] x86, microcode, intel: forbid some incorrect metadata Henrique de Moraes Holschuh
2014-10-05 17:34 ` Borislav Petkov
2014-10-05 19:37 ` Henrique de Moraes Holschuh
2014-10-05 21:13 ` Borislav Petkov
2014-10-05 21:49 ` Henrique de Moraes Holschuh
2014-10-06 5:15 ` Borislav Petkov
2014-09-08 17:37 ` [PATCH 2/8] x86, microcode, intel: don't update each HT core twice Henrique de Moraes Holschuh
2014-10-20 13:32 ` Borislav Petkov
2014-10-20 18:24 ` Henrique de Moraes Holschuh
2014-10-28 17:31 ` Borislav Petkov
2014-10-31 18:43 ` Henrique de Moraes Holschuh
2014-11-01 11:06 ` Borislav Petkov
2014-11-01 19:20 ` Henrique de Moraes Holschuh
2014-11-04 15:53 ` Borislav Petkov
2014-09-08 17:37 ` [PATCH 3/8] x86, microcode, intel: clarify log messages Henrique de Moraes Holschuh
2014-10-20 13:52 ` Borislav Petkov
2014-10-21 14:13 ` Henrique de Moraes Holschuh
2014-10-29 9:54 ` Borislav Petkov
2014-10-31 20:08 ` Henrique de Moraes Holschuh
2014-11-07 17:37 ` Borislav Petkov
2014-09-08 17:37 ` [PATCH 4/8] x86, microcode, intel: add error logging to early update driver Henrique de Moraes Holschuh
2014-10-20 15:08 ` Borislav Petkov
2014-10-21 14:10 ` Henrique de Moraes Holschuh
2014-10-30 17:41 ` Borislav Petkov
2014-10-30 18:15 ` Joe Perches
2014-10-31 20:10 ` Henrique de Moraes Holschuh
2014-09-08 17:37 ` [PATCH 5/8] x86, microcode, intel: don't check extsig entry checksum Henrique de Moraes Holschuh
2014-10-30 20:25 ` Borislav Petkov
2014-10-31 17:14 ` Henrique de Moraes Holschuh
2014-11-07 17:49 ` Borislav Petkov
2014-09-08 17:37 ` [PATCH 6/8] x86, microcode, intel: use cpuid explicitly instead of sync_core Henrique de Moraes Holschuh
2014-11-07 17:56 ` Borislav Petkov
2014-11-07 18:40 ` Henrique de Moraes Holschuh
2014-11-07 19:48 ` Borislav Petkov
2014-09-08 17:37 ` [PATCH 7/8] x86, microcode, intel: guard against misaligned microcode data Henrique de Moraes Holschuh
2014-09-18 0:48 ` Henrique de Moraes Holschuh
2014-11-07 19:59 ` Borislav Petkov
2014-11-07 22:54 ` Henrique de Moraes Holschuh
2014-11-07 23:48 ` Borislav Petkov
2014-11-08 21:57 ` Henrique de Moraes Holschuh
2014-11-11 10:47 ` Borislav Petkov
2014-11-11 16:57 ` Henrique de Moraes Holschuh
2014-11-11 17:13 ` Borislav Petkov
2014-11-11 19:54 ` Henrique de Moraes Holschuh
2014-11-12 12:31 ` Borislav Petkov
2014-11-13 0:18 ` Henrique de Moraes Holschuh
2014-11-13 11:53 ` Borislav Petkov
2014-11-15 23:10 ` Henrique de Moraes Holschuh
2014-11-24 17:35 ` Borislav Petkov
2014-11-25 13:29 ` Henrique de Moraes Holschuh
2014-09-08 17:37 ` [PATCH 8/8] x86, microcode, intel: defend apply_microcode_intel with BUG_ON Henrique de Moraes Holschuh
2014-11-07 20:05 ` Borislav Petkov [this message]
2014-11-07 22:56 ` Henrique de Moraes Holschuh
2014-11-07 23:48 ` Borislav Petkov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20141107200501.GF5180@pd.tnic \
--to=bp@alien8.de \
--cc=hmh@hmh.eng.br \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).