From mboxrd@z Thu Jan  1 00:00:00 1970
Reply-To: kernel-hardening@lists.openwall.com
Date: Sat, 30 Jan 2016 15:34:56 +0100
From: Jann Horn <jann@thejh.net>
Message-ID: <20160130143455.GA27221@pc.thejh.net>
References: <1453622354-50686-1-git-send-email-sbauer@eng.utah.edu>
 <1453622354-50686-3-git-send-email-sbauer@eng.utah.edu>
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In-Reply-To: <1453622354-50686-3-git-send-email-sbauer@eng.utah.edu>
Subject: Re: [kernel-hardening] [RFC PATCH 2/2] x86: SROP mitigation:
 implement signal cookies
To: kernel-hardening@lists.openwall.com
List-ID: <kernel-hardening.lists.openwall.com>


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On Sun, Jan 24, 2016 at 12:59:14AM -0700, Scott Bauer wrote:
> This patch adds SROP mitigation logic to the x86 signal delivery
> and sigreturn code. The cookie is placed in the unused alignment
> space above the saved FP state, if it exists. If there is no FP
> state to save then the cookie is placed in the alignment space above
> the sigframe.

A nice side effect of this patch is that it will mitigate the ability of
a process in strict seccomp to effectively call sigprocmask() using
sigreturn.

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