From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from second.openwall.net (second.openwall.net [193.110.157.125]) by smtp.lore.kernel.org (Postfix) with SMTP id 11861D6ACE8 for ; Wed, 27 Nov 2024 15:16:03 +0000 (UTC) Received: (qmail 9506 invoked by uid 550); 27 Nov 2024 15:15:54 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 9480 invoked from network); 27 Nov 2024 15:15:53 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=GCS2DQ Uac3TMxyLYLwiZmv8x54wgn5Xk1pl4/F6v0m0=; b=iqIzHT3enT0CDH3A46gu9i EZdykzNoAwSOXOa8g6bp5tEcZ5ODbWqx/tvnX/bE62xurMdnL9iYj9BKi4sFZUyb bF++yjbC6KQqTbuw4Z9l017b3SqIYljh8Pg/4zb/FYOiRZWPC+O5eiiPxM+x5pi8 SYULlPbc6i9CHHMtwogs56NIe2vgPimoh56yFuhzVuIVT2tYIDYmcljzldGnRmRj f7si3zFqf+YJI0YhqAdYXo87LRjEw/bYVEnwJtLzKB4vYQBe7wkOU5DtI9fCx1G0 Q5euZ+ZkncA1NGmTxCpghOmr4S9XknE3vv7narDXXtcttxpFFowjef4YTd6YAB8A == Message-ID: Subject: Re: [PATCH v21 6/6] samples/check-exec: Add an enlighten "inc" interpreter and 28 tests From: Mimi Zohar To: =?ISO-8859-1?Q?Micka=EBl_Sala=FCn?= Cc: Al Viro , Christian Brauner , Kees Cook , Paul Moore , Serge Hallyn , Adhemerval Zanella Netto , Alejandro Colomar , Aleksa Sarai , Andrew Morton , Andy Lutomirski , Arnd Bergmann , Casey Schaufler , Christian Heimes , Dmitry Vyukov , Elliott Hughes , Eric Biggers , Eric Chiang , Fan Wu , Florian Weimer , Geert Uytterhoeven , James Morris , Jan Kara , Jann Horn , Jeff Xu , Jonathan Corbet , Jordan R Abrahams , Lakshmi Ramasubramanian , Linus Torvalds , Luca Boccassi , Luis Chamberlain , "Madhavan T . Venkataraman" , Matt Bobrowski , Matthew Garrett , Matthew Wilcox , Miklos Szeredi , Nicolas Bouchinet , Scott Shell , Shuah Khan , Stephen Rothwell , Steve Dower , Steve Grubb , "Theodore Ts'o" , 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 Date: Wed, 27 Nov 2024 10:15:00 -0500 In-Reply-To: <20241127.Ob8DaeR9xaul@digikod.net> References: <20241112191858.162021-1-mic@digikod.net> <20241112191858.162021-7-mic@digikod.net> <20241122.ahY1pooz1ing@digikod.net> <623f89b4de41ac14e0e48e106b846abc9e9d70cf.camel@linux.ibm.com> <20241127.Ob8DaeR9xaul@digikod.net> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.4 (3.52.4-2.fc40) MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: Kd8WuLouAhuXRPFpDaVk4_8ACYrn9rDN X-Proofpoint-ORIG-GUID: 0WhnWlE6pkwgsa_A3gcl6aVmeAxdV_mA X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 mlxscore=0 mlxlogscore=999 suspectscore=0 impostorscore=0 malwarescore=0 spamscore=0 clxscore=1015 adultscore=0 lowpriorityscore=0 bulkscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2411270119 On Wed, 2024-11-27 at 13:10 +0100, Micka=C3=ABl Sala=C3=BCn wrote: > On Tue, Nov 26, 2024 at 12:41:45PM -0500, Mimi Zohar wrote: > > On Fri, 2024-11-22 at 15:50 +0100, Micka=C3=ABl Sala=C3=BCn wrote: > > > On Thu, Nov 21, 2024 at 03:34:47PM -0500, Mimi Zohar wrote: > > > > Hi Micka=C3=ABl, > > > >=20 > > > > On Tue, 2024-11-12 at 20:18 +0100, Micka=C3=ABl Sala=C3=BCn wrote: > > > > >=20 > > > > > + > > > > > +/* Returns 1 on error, 0 otherwise. */ > > > > > +static int interpret_stream(FILE *script, char *const script_nam= e, > > > > > + char *const *const envp, const bool restrict_stream) > > > > > +{ > > > > > + int err; > > > > > + char *const script_argv[] =3D { script_name, NULL }; > > > > > + char buf[128] =3D {}; > > > > > + size_t buf_size =3D sizeof(buf); > > > > > + > > > > > + /* > > > > > + * We pass a valid argv and envp to the kernel to emulate a nat= ive > > > > > + * script execution. We must use the script file descriptor in= stead of > > > > > + * the script path name to avoid race conditions. > > > > > + */ > > > > > + err =3D execveat(fileno(script), "", script_argv, envp, > > > > > + AT_EMPTY_PATH | AT_EXECVE_CHECK); > > > >=20 > > > > At least with v20, the AT_CHECK always was being set, independent o= f whether > > > > set-exec.c set it. I'll re-test with v21. > > >=20 > > > AT_EXECVE_CEHCK should always be set, only the interpretation of the > > > result should be relative to securebits. This is highlighted in the > > > documentation. > >=20 > > Sure, that sounds correct. With an IMA-appraisal policy, any unsigned = script > > with the is_check flag set now emits an "cause=3DIMA-signature-required= " audit > > message. However since IMA-appraisal isn't enforcing file signatures, = this > > sounds wrong. > >=20 > > New audit messages like "IMA-signature-required-by-interpreter" and "IM= A- > > signature-not-required-by-interpreter" would need to be defined based o= n the > > SECBIT_EXEC_RESTRICT_FILE. >=20 > It makes sense. Could you please send a patch for these > IMA-*-interpreter changes? I'll include it in the next series. Sent as an RFC. The audit message is only updated for the missing signatur= e case. However, all of the audit messages in ima_appraise_measurement() sho= uld be updated. The current method doesn't scale. Mimi > >=20 > >=20 > > > >=20 > > > > > + if (err && restrict_stream) { > > > > > + perror("ERROR: Script execution check"); > > > > > + return 1; > > > > > + } > > > > > + > > > > > + /* Reads script. */ > > > > > + buf_size =3D fread(buf, 1, buf_size - 1, script); > > > > > + return interpret_buffer(buf, buf_size); > > > > > +} > > > > > + > > > >=20 > > > >=20 > > >=20 > >=20 > >=20 >=20