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Date:   Sat, 30 Nov 2019 08:13:01 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Max Filippov <jcmvbkbc@gmail.com>
Cc:     linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
        Andy Lutomirski <luto@amacapital.net>,
        Will Drewry <wad@chromium.org>, Shuah Khan <shuah@kernel.org>
Subject: Re: [PATCH] tools/testing/selftests/seccomp: change USER_NOTIF_MAGIC
 definition
Message-ID: <201911300811.7D70D30@keescook>
References: <20191129055128.25952-1-jcmvbkbc@gmail.com>
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On Thu, Nov 28, 2019 at 09:51:28PM -0800, Max Filippov wrote:
> USER_NOTIF_MAGIC is used to both initialize seccomp_notif_resp::val and
> verify syscall resturn value. On 32-bit architectures syscall return
> value has type long, but the value of USER_NOTIF_MAGIC has type long
> long because it doesn't fit into long. As a result all syscall return
> value comparisons with USER_NOTIF_MAGIC are false. This is also reported
> by the compiler when '-W' is added to CFLAGS.

Hi! Thanks for sending this. There is already a patch in the pipeline
for getting it fixed; it should show up in Linus's tree soon:
https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?h=for-next/seccomp&id=223e660bc7638d126a0e4fbace4f33f2895788c4

-- 
Kees Cook