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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0E913C433F5 for ; Fri, 4 Mar 2022 19:04:00 +0000 (UTC) Received: from localhost ([::1]:35002 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nQDDb-00064H-16 for qemu-devel@archiver.kernel.org; Fri, 04 Mar 2022 14:03:59 -0500 Received: from eggs.gnu.org ([209.51.188.92]:51740) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nQD8A-0002mZ-60 for qemu-devel@nongnu.org; Fri, 04 Mar 2022 13:58:22 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:58901) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nQD86-0000VX-Qq for qemu-devel@nongnu.org; Fri, 04 Mar 2022 13:58:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646420298; 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=gPvFWCKXMBPsfZIqyM+P/NLAeYAgxvVXGpPRUB48jL4=; b=bb0n+1uUql7EP5IDFttKI6ATHCvBEj0EpzvwADS33shqxTGFe8XwSDL2ptvseiChPw+c9C 1FWq2fWaGfhZ/CcBLHpxRuFrQdHQLQfYlla/VS76yz1Lnr4r13EGIcBNfqiJY0ZAz8zEEN gBiHHuDTrK6cCLb2xZ1sA+Nf11nZb4g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-515-JyhcCTGVOxK599qthFNdAA-1; Fri, 04 Mar 2022 13:58:15 -0500 X-MC-Unique: JyhcCTGVOxK599qthFNdAA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 37645805EE5; Fri, 4 Mar 2022 18:58:14 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.39.194.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id A909687B87; Fri, 4 Mar 2022 18:57:35 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH v2 2/8] os-posix: refactor code handling the -runas argument Date: Fri, 4 Mar 2022 18:56:14 +0000 Message-Id: <20220304185620.3272401-3-berrange@redhat.com> In-Reply-To: <20220304185620.3272401-1-berrange@redhat.com> References: <20220304185620.3272401-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , libvir-list@redhat.com, Stefan Weil , Hanna Reitz , Gerd Hoffmann , Paolo Bonzini , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Eric Blake Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Change the change_process_uid() function so that it takes its input as parameters instead of relying on static global variables. Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrangé --- os-posix.c | 83 +++++++++++++++++++++++++----------------------------- 1 file changed, 39 insertions(+), 44 deletions(-) diff --git a/os-posix.c b/os-posix.c index 7cd662098e..5a127feee2 100644 --- a/os-posix.c +++ b/os-posix.c @@ -42,13 +42,9 @@ #include #endif -/* - * Must set all three of these at once. - * Legal combinations are unset by name by uid - */ -static struct passwd *user_pwd; /* NULL non-NULL NULL */ -static uid_t user_uid = (uid_t)-1; /* -1 -1 >=0 */ -static gid_t user_gid = (gid_t)-1; /* -1 -1 >=0 */ +static char *user_name; +static uid_t user_uid = (uid_t)-1; +static gid_t user_gid = (gid_t)-1; static const char *chroot_dir; static int daemonize; @@ -100,7 +96,8 @@ void os_set_proc_name(const char *s) } -static bool os_parse_runas_uid_gid(const char *optarg) +static bool os_parse_runas_uid_gid(const char *optarg, + uid_t *runas_uid, gid_t *runas_gid) { unsigned long lv; const char *ep; @@ -120,9 +117,8 @@ static bool os_parse_runas_uid_gid(const char *optarg) return false; } - user_pwd = NULL; - user_uid = got_uid; - user_gid = got_gid; + *runas_uid = got_uid; + *runas_gid = got_gid; return true; } @@ -132,13 +128,18 @@ static bool os_parse_runas_uid_gid(const char *optarg) */ int os_parse_cmd_args(int index, const char *optarg) { + struct passwd *user_pwd; + switch (index) { case QEMU_OPTION_runas: user_pwd = getpwnam(optarg); if (user_pwd) { - user_uid = -1; - user_gid = -1; - } else if (!os_parse_runas_uid_gid(optarg)) { + user_uid = user_pwd->pw_uid; + user_gid = user_pwd->pw_gid; + user_name = g_strdup(user_pwd->pw_name); + } else if (!os_parse_runas_uid_gid(optarg, + &user_uid, + &user_gid)) { error_report("User \"%s\" doesn't exist" " (and is not :)", optarg); @@ -158,41 +159,33 @@ int os_parse_cmd_args(int index, const char *optarg) return 0; } -static void change_process_uid(void) +static void change_process_uid(uid_t uid, gid_t gid, const char *name) { - assert((user_uid == (uid_t)-1) || user_pwd == NULL); - assert((user_uid == (uid_t)-1) == - (user_gid == (gid_t)-1)); - - if (user_pwd || user_uid != (uid_t)-1) { - gid_t intended_gid = user_pwd ? user_pwd->pw_gid : user_gid; - uid_t intended_uid = user_pwd ? user_pwd->pw_uid : user_uid; - if (setgid(intended_gid) < 0) { - error_report("Failed to setgid(%d)", intended_gid); - exit(1); - } - if (user_pwd) { - if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) { - error_report("Failed to initgroups(\"%s\", %d)", - user_pwd->pw_name, user_pwd->pw_gid); - exit(1); - } - } else { - if (setgroups(1, &user_gid) < 0) { - error_report("Failed to setgroups(1, [%d])", - user_gid); - exit(1); - } - } - if (setuid(intended_uid) < 0) { - error_report("Failed to setuid(%d)", intended_uid); + if (setgid(gid) < 0) { + error_report("Failed to setgid(%d)", gid); + exit(1); + } + if (name) { + if (initgroups(name, gid) < 0) { + error_report("Failed to initgroups(\"%s\", %d)", + name, gid); exit(1); } - if (setuid(0) != -1) { - error_report("Dropping privileges failed"); + } else { + if (setgroups(1, &gid) < 0) { + error_report("Failed to setgroups(1, [%d])", + gid); exit(1); } } + if (setuid(uid) < 0) { + error_report("Failed to setuid(%d)", uid); + exit(1); + } + if (setuid(0) != -1) { + error_report("Dropping privileges failed"); + exit(1); + } } static void change_root(void) @@ -275,7 +268,9 @@ void os_setup_post(void) } change_root(); - change_process_uid(); + if (user_uid != -1 && user_gid != -1) { + change_process_uid(user_uid, user_gid, user_name); + } if (daemonize) { uint8_t status = 0; -- 2.34.1