From: Kees Cook <keescook@chromium.org>
To: John Wood <john.wood@gmx.com>
Cc: Jann Horn <jannh@google.com>, Jonathan Corbet <corbet@lwn.net>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Shuah Khan <shuah@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Arnd Bergmann <arnd@arndb.de>, Andi Kleen <ak@linux.intel.com>,
valdis.kletnieks@vt.edu,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Randy Dunlap <rdunlap@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-arch@vger.kernel.org,
linux-hardening@vger.kernel.org,
kernel-hardening@lists.openwall.com
Subject: Re: [PATCH v8 0/8] Fork brute force attack mitigation
Date: Tue, 8 Jun 2021 16:19:31 -0700 [thread overview]
Message-ID: <202106081616.EC17DC1D0D@keescook> (raw)
In-Reply-To: <20210605150405.6936-1-john.wood@gmx.com>
On Sat, Jun 05, 2021 at 05:03:57PM +0200, John Wood wrote:
> [...]
> the kselftest to avoid the detection ;) ). So, in this version, to track
> all the statistical data (info related with application crashes), the
> extended attributes feature for the executable files are used. The xattr is
> also used to mark the executables as "not allowed" when an attack is
> detected. Then, the execve system call rely on this flag to avoid following
> executions of this file.
I have some concerns about this being actually usable and not creating
DoS situations. For example, let's say an attacker had found a hard-to-hit
bug in "sudo", and starts brute forcing it. When the brute LSM notices,
it'll make "sudo" unusable for the entire system, yes?
And a reboot won't fix it, either, IIUC.
It seems like there is a need to track "user" running "prog", and have
that be timed out. Are there use-cases here where that wouldn't be
sufficient?
-Kees
--
Kees Cook
next prev parent reply other threads:[~2021-06-08 23:19 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-05 15:03 [PATCH v8 0/8] Fork brute force attack mitigation John Wood
2021-06-05 15:03 ` [PATCH v8 1/8] security: Add LSM hook at the point where a task gets a fatal signal John Wood
2021-06-05 15:03 ` [PATCH v8 2/8] security/brute: Define a LSM and add sysctl attributes John Wood
2021-06-05 15:04 ` [PATCH v8 3/8] security/brute: Detect a brute force attack John Wood
2021-06-05 15:04 ` [PATCH v8 4/8] security/brute: Mitigate " John Wood
2021-06-05 15:04 ` [PATCH v8 5/8] security/brute: Notify to userspace "task killed" John Wood
2021-06-05 15:04 ` [PATCH v8 6/8] selftests/brute: Add tests for the Brute LSM John Wood
2021-06-05 15:04 ` [PATCH v8 7/8] Documentation: Add documentation " John Wood
2021-06-05 15:04 ` [PATCH v8 8/8] MAINTAINERS: Add a new entry " John Wood
2021-06-08 23:19 ` Kees Cook [this message]
2021-06-08 23:38 ` [PATCH v8 0/8] Fork brute force attack mitigation Andi Kleen
2021-06-09 16:52 ` Kees Cook
2021-06-11 15:41 ` John Wood
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