All of lore.kernel.org
 help / color / mirror / Atom feed
From: Borislav Petkov <bp@alien8.de>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	the arch/x86 maintainers <x86@kernel.org>,
	linux-edac@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: x86, mce: Fix stack out-of-bounds write in mce-inject.c:flags_read()
Date: Fri, 27 Apr 2018 18:59:39 +0200	[thread overview]
Message-ID: <20180427165939.GG15229@pd.tnic> (raw)

On Fri, Apr 27, 2018 at 09:37:08AM -0700, Luck, Tony wrote:
> Each of the strings that we want to put into the buf[MAX_FLAG_OPT_SIZE]
> in flags_read() is two characters. But the sprintf() adds a trailing newline
> and will add a terminating NUL byte. So MAX_FLAG_OPT_SIZE needs to be 4.

... and I dumped the n here:

	n = sprintf(buf, "%s\n", flags_options[inj_type])

and it was 3 but sprintf() calls vsnprintf() and *that* does return:

" * The return value is the number of characters which would
 * be generated for the given input, excluding the trailing
 * '\0', as per ISO C99."

So I'll extend the commit message with that and apply it.

Thanks.

WARNING: multiple messages have this Message-ID (diff)
From: Borislav Petkov <bp@alien8.de>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	the arch/x86 maintainers <x86@kernel.org>,
	linux-edac@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86, mce: Fix stack out-of-bounds write in mce-inject.c:flags_read()
Date: Fri, 27 Apr 2018 18:59:39 +0200	[thread overview]
Message-ID: <20180427165939.GG15229@pd.tnic> (raw)
In-Reply-To: <20180427163707.ktaiysvbk3yhk4wm@agluck-desk>

On Fri, Apr 27, 2018 at 09:37:08AM -0700, Luck, Tony wrote:
> Each of the strings that we want to put into the buf[MAX_FLAG_OPT_SIZE]
> in flags_read() is two characters. But the sprintf() adds a trailing newline
> and will add a terminating NUL byte. So MAX_FLAG_OPT_SIZE needs to be 4.

... and I dumped the n here:

	n = sprintf(buf, "%s\n", flags_options[inj_type])

and it was 3 but sprintf() calls vsnprintf() and *that* does return:

" * The return value is the number of characters which would
 * be generated for the given input, excluding the trailing
 * '\0', as per ISO C99."

So I'll extend the commit message with that and apply it.

Thanks.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

             reply	other threads:[~2018-04-27 16:59 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-27 16:59 Borislav Petkov [this message]
2018-04-27 16:59 ` [PATCH] x86, mce: Fix stack out-of-bounds write in mce-inject.c:flags_read() Borislav Petkov
  -- strict thread matches above, loose matches on Subject: below --
2018-05-06 10:52 [tip:ras/core] x86/MCE: Fix stack out-of-bounds write in mce-inject.c: Flags_read() tip-bot for Borislav Petkov
2018-05-06 10:52 ` tip-bot for Luck, Tony
2018-04-27 16:37 x86, mce: Fix stack out-of-bounds write in mce-inject.c:flags_read() Luck, Tony
2018-04-27 16:37 ` [PATCH] " Luck, Tony
2018-04-27 15:24 stack out-of-bounds write in mce-inject.c Dmitry Vyukov
2018-04-27 15:41 ` Borislav Petkov
2018-04-27 16:06   ` Dmitry Vyukov

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=20180427165939.GG15229@pd.tnic \
    --to=bp@alien8.de \
    --cc=dvyukov@google.com \
    --cc=hpa@zytor.com \
    --cc=linux-edac@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=tony.luck@intel.com \
    --cc=x86@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.