From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C20FD149C64 for ; Mon, 8 Jul 2024 17:33:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720460018; cv=none; b=drAe5tB4gxEikfMigFroCrzZvd+lF2QKGm4x1zL4b7wEc7mPiEjUDnG1vt/AM3/k0ZJlu2UTw3NINamwdKYKWqPkBHCKUfgjeg2R1Xh0Ujd3eXSsBc22EWuyLsu0wEVt4s1BJAoGARK78h4bbd9B4qtVErpeJop7/Z0RAO4YdLE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720460018; c=relaxed/simple; bh=SGGTfSOeRUwxz6VC/qRrj5DKzqlNaTgG40wQSssXK7c=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=SxYPZD480LqlNTC0Mz73gH//oDoGW5nxMd0ptm+Qt7sY8nuiLowULrwZk740dfnmQElUipkIVLIcwqgiXe5pFOF4RfHdLk8pccwLWAciwI07cJss+h1GcrxrW/XtFaJuhGUnIOSUQMzb6CFMVHIXIkSYJf5QJxfoFq0he/QvfRQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=e8P8LZit; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="e8P8LZit" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1720460015; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NzysFrdc8w10bKEbWw8ppHuT/B9oi64/ANDYqxDHLjs=; b=e8P8LZit6wLglcAZcL+dzOY6pkf3XHaUC2u+bHpp5HbjI1GM665GPOb1uMyHYNimjUzo7f IPnnpLrpXaKHxoKvZ2Qmx/o+WQXAfULo8MgGvMFNchjx/3Gg0637rzyqSzmuqw0OaWBU0u b2OKv7SM1AFULpIPH6boNzak8nAF2aw= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-401-i2EE8bhrPTu-d51vmcgTDg-1; Mon, 08 Jul 2024 13:33:32 -0400 X-MC-Unique: i2EE8bhrPTu-d51vmcgTDg-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9014B1956046; Mon, 8 Jul 2024 17:33:24 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.45.224.113]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2CE9B19560AE; Mon, 8 Jul 2024 17:33:05 +0000 (UTC) From: Florian Weimer To: Jeff Xu Cc: =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , Al Viro , Christian Brauner , Kees Cook , Linus Torvalds , Paul Moore , "Theodore Ts'o" , Alejandro Colomar , Aleksa Sarai , Andrew Morton , Andy Lutomirski , Arnd Bergmann , Casey Schaufler , Christian Heimes , Dmitry Vyukov , Eric Biggers , Eric Chiang , Fan Wu , Geert Uytterhoeven , James Morris , Jan Kara , Jann Horn , Jonathan Corbet , Jordan R Abrahams , Lakshmi Ramasubramanian , Luca Boccassi , Luis Chamberlain , "Madhavan T . Venkataraman" , Matt Bobrowski , Matthew Garrett , Matthew Wilcox , Miklos Szeredi , Mimi Zohar , Nicolas Bouchinet , Scott Shell , Shuah Khan , Stephen Rothwell , Steve Dower , Steve Grubb , Thibaut Sautereau , Vincent Strubel , Xiaoming Ni , Yin Fengwei , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: Re: [RFC PATCH v19 1/5] exec: Add a new AT_CHECK flag to execveat(2) In-Reply-To: (Jeff Xu's message of "Mon, 8 Jul 2024 09:40:45 -0700") References: <20240704190137.696169-1-mic@digikod.net> <20240704190137.696169-2-mic@digikod.net> <87bk3bvhr1.fsf@oldenburg.str.redhat.com> <87ed83etpk.fsf@oldenburg.str.redhat.com> Date: Mon, 08 Jul 2024 19:33:03 +0200 Message-ID: <87r0c3dc1c.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 * Jeff Xu: > On Mon, Jul 8, 2024 at 9:26=E2=80=AFAM Florian Weimer wrote: >> >> * Jeff Xu: >> >> > Will dynamic linkers use the execveat(AT_CHECK) to check shared >> > libraries too ? or just the main executable itself. >> >> I expect that dynamic linkers will have to do this for everything they >> map. > Then all the objects (.so, .sh, etc.) will go through the check from > execveat's main to security_bprm_creds_for_exec(), some of them might > be specific for the main executable ? If we want to avoid that, we could have an agreed-upon error code which the LSM can signal that it'll never fail AT_CHECK checks, so we only have to perform the extra system call once. Thanks, Florian