linux-kernel - Re: [PATCH 2/2] ARM: fix framepointer check in unwind

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: <CAFrcx1kCAjoMxBeqaO+iS2CGzX6omuW1reL636Lyj=bg5DB1Rg@mail.gmail.com>
Date:	Thu, 5 Dec 2013 13:45:26 +0100
From:	Jean Pihet <jean.pihet@...aro.org>
To:	Konstantin Khlebnikov <k.khlebnikov@...sung.com>
Cc:	Russell King <linux@....linux.org.uk>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	Will Deacon <will.deacon@....com>,
	Vyacheslav Tyrtov <v.tyrtov@...sung.com>
Subject: Re: [PATCH 2/2] ARM: fix framepointer check in unwind_frame

On 5 December 2013 09:34, Konstantin Khlebnikov
<k.khlebnikov@...sung.com> wrote:
> This patch fixes corner case when (fp + 4) overflows unsigned long,
> for example: fp = 0xFFFFFFFF -> fp + 4 == 3.
>
> Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@...sung.com>
> ---
>  arch/arm/kernel/stacktrace.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
> index 00f79e5..af4e8c8 100644
> --- a/arch/arm/kernel/stacktrace.c
> +++ b/arch/arm/kernel/stacktrace.c
> @@ -31,7 +31,7 @@ int notrace unwind_frame(struct stackframe *frame)
>         high = ALIGN(low, THREAD_SIZE);
>
>         /* check current frame pointer is within bounds */
> -       if (fp < (low + 12) || fp + 4 >= high)
> +       if (fp < low + 12 || fp > high - 4)
Shouldn't that use the '>=' comparison?

Jean
>                 return -EINVAL;
>
>         /* restore the registers from the stack frame */
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/