From patchwork Tue Sep 27 19:54:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Casey Schaufler X-Patchwork-Id: 12991285 X-Patchwork-Delegate: paul@paul-moore.com 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DB55C54EE9 for ; Tue, 27 Sep 2022 20:12:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232590AbiI0UMA (ORCPT ); Tue, 27 Sep 2022 16:12:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231502AbiI0ULj (ORCPT ); Tue, 27 Sep 2022 16:11:39 -0400 Received: from sonic308-15.consmr.mail.ne1.yahoo.com (sonic308-15.consmr.mail.ne1.yahoo.com [66.163.187.38]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E45E21E1CC1 for ; Tue, 27 Sep 2022 13:10:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1664309455; bh=IoOvUAvVh41iE+IwVtDNSby8AcgSirQAfmPuWAn2bxg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject:Reply-To; b=TERmwRUpvPcjZTJSkbBNLVuVYfnbxoNNEFflMLjueeTIT6pTW7V2fGviDIBrFG7La0oAbZ1ogX7CYPYC8X0Hvkj5hLT3hs0Y6EX1EOzWBCGj+Dwmlwc/tnOgr5a/5k7e5o57QHRvcsf/72iFw8zSHOR4Cpa2pRxm9cPa9+cxX6lW/Qn0aFKQZsTIY+LRJCf4CC2P1vlvVrX5rse8LoWN6pzF62ZhBXLS6Wu9vHoGqIyP9GE3PZCwJHSDb2kbogsXOgNGL6CFMT46504mzKf/VsFQwELgkX6NDDJ/SZApcDpopm90eSrJUQHnorN1GO6AqqO0DcTbVmHAblznDXSRMA== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1664309455; bh=UynV8x9bI69/c7VTXup7QVzm3oCLLMvc/GCrRTaA4Ok=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=SbPFs9H/CW2VxCpA0vIE+m3Jjm86oKzcSo3Oon5vl+BvVd78q3eHJL+5IKGGQnjuBaR6SgIpWxS+WDcKeLK+iXq0o6V+7nF9V2eMw4mE0+Vxe1MktzdtsAvWryGy/57kPeEpKqiFsurPHTe4yP2ccNFBXH2jNjiHEWzdb4msknsLazdQ5zc+YcnOj0N38bpF6uJQkH+9JhEbLzam78Wjstppwa0HPg/u6zJf9JFwJ+YZR7mT1rZzHWk+BFuvJrOxT//RAj2as8heRQqfbyq/QThl9Kjx3lbLrZ2KANYEIIbbHT2HyqzPsl7uBoFIU6xKr2qMKEwpH5hPvHAbunH8XQ== X-YMail-OSG: SoszQHEVM1npuvo43EkpfVrp4aSVhMBmMwAlLPhfp5UJf1uc4CkLLTLJ4u.CcsH Jdi.1JMeDIKrhW2.lv095DQ2JwGMesYnCpb07dUbe6mIA6uXGi8gStU1uVIP9VcsVyiuhvQEOXHZ pZdr9O3qjTXLMqZGemCAdTQb4WOtLo8_mKdeA_LCbAWdmYfNXNkUMFSAyRF0RORTpU2QAb8eA2EF kJ1BqK2t9jzcwQzvNx7FLA01A0yH_g3.qTrXKn2DqfNtTzHqoaoDpV6SthLrjxH1i1g7uNLq05o5 MalsoJGN06nmml8bmvnfdWuf8Mu.tsJu7oZTcNT4DU962QDBDAJG6QDIwBsW5d..oHiG4n3qX4px Lw7xc640k3uSkFD8qLpgj.NEUBwP40Pca9ntkfIrYqezxqTezhgiM3OyZKYJL797xs2PH.2zP5P2 quebK4GcgVXdOGoBcNXf64HQFSuLqGfZxye5sd8pQpemWQel16vL1e7MxI6BLdLRhyzphhOyNFu8 5sBgSPGFhRoti3wEXs3_8SgNRZcP9ncWnZXJI6LLXShZBngEzhWjvrMqic5f6yaa1DJybYyfoWhU wA8ua5cVXVU3VW9QLY6wGBDl9rmQ3eNpFXoIDVik8Y2wYYVWNntoyjALtACIUmQjpZX9EQLXctpF Y55dgyrLGY_DBf8R0.kMUYhO1aNnkCyUbveVhYIIBTPXWj0z7mhx7j3_ft1yhR7WrINkZP8W5phY Xs68VTvN8Jjn0iPZFdfhCV.5FPfARtW3fYCc__xSI67tkOYnUh9JBqLHkGGoTW4XZO57GQ2H3CzX KDI.EgDEJUlXVq_ptkpOnfGkhlyuPCcT7KA1LTUuUi3OXa0T0DAay5Mxvl1awa_Vjnw1a.WZ0Jf0 rHvHi16bgYMnj5jC540FlmRkddGYYN7z7VyHpzXtHHlu11Eru9q3IlAN1R5tvv5TUEqWXCs6CAzc E_bnf4kWQH78jOuysHpOk3NWGHBBKwilDU0Vp2QeprOfkwEV7ErZ14R5noqtNqxRAlA87dUzyq5o 7oPrY.T3tC7SVwRhHBRuXa1FP2rNtzc_CrLjm0WUq8O4wVNkKz8__Y79.eoShwplw5wns.9bTBDd TbCLWDV3Xc7LP_tn6uEfdSHkcVVx0FR4Kc8h5NB9nqyELBdID1os3bIVtKZ.u2ybXkT12.4fukk_ upKp0awUAm8Xm8dvuT6gQqNYJ3YfEXQjOsiP3OoY44Ul6frQjndOO73dAFvlzeTEyUYadiQV6Guw PX2DRJUg7bqeGm2RxrI2NA0k03jwfEh7evJ11sSHHWXhc3vNzc8bvHeWG1VppnoieDHpFGYy1QK5 59wBYXQwKcpHJe1exG297rpCCPC37ChPzDeG057YonHjUppyR1DkPXHBRU4olttoAEoXIG3lwJIs 4wuIlRQk0domFuj9RyWOfZybIJasf5X7JsWUAPaOPwa5L5xs7lpkzRwvCNavTUicgxLIryevH8Fi LTpE.QkgJqgRfwNJwlus5pNgHaWp.TkKdxpg0Q4ocjz1QBvtDl77tVMmjgYK__CCf3ZStLv5bjvO qGMYiiAQ9IuhOrRGb42I1t752UM9f5y5xYfDhrQouzvplYWTJ3KJuP5XoQiBxklDh6_QPyA_uHpF wOrFRcSGIh0vDcztBsitNJhiQ.qAhtSOzHsP3O_IhE3et_AjbNPzr27XqIxvM80sc1JTyk2oQ7AK zP21FVPwxyHbWW.rlEWDwkrT4F.8V71r4jANX8YlHVHInS3s.9NPrqeO3TJvvGwq0.aD4dvM4Gp7 YY4zj0UTN83YUcOiD.d9C6gHfRsvWQ1EQqerin3RZ_ImjH2Z9pUWM8Ip7_3Szu59MzQgQFElsrc8 .tu..4VcG1zWumD_qOBbI9Go_drmMasCdQHQjKiTk4hD.tByQz09.EUtyRqABYI8xdktJdBnuFLN HX2OcuBziTxhO52smLSKYh5coGOvwog9MzXLp4kxJKQy58ke8cnys.vCMSL.oaxiWhTsVNMNcJLn ulse2fHwDUFSidkZ_t8gMiiWjb.y5KURbVfCPjo7CWlPVbbZifHRX8DA2NtvQuiRn324I5kPViTX Dx3yM4MmNYjwgZR5cG8115YpAUlowCKQ5tVrJXXNEWXOaQnA69ZxQh4jCt2YtFS4.boXlmLMFB0B T12S0LbboSIQDL1N1xR6tJS7VtRBfGOdGeX.f4VKJEn6cpp0ioTLWXDkqWNYQdTyu4EYo4CM9j.x gYV599U3fsq9MOEOOmAKtwI2KTsfg.q7w2_bQ5cHijJ_S62auJTL754HC.8xX.enebkRkqWORK3E UjLjvZqPoyGbB6jpmRfJG87Ot8q2LZAd8inbWttU- X-Sonic-MF: Received: from sonic.gate.mail.ne1.yahoo.com by sonic308.consmr.mail.ne1.yahoo.com with HTTP; Tue, 27 Sep 2022 20:10:55 +0000 Received: by hermes--production-gq1-7dfd88c84d-nvfk6 (Yahoo Inc. Hermes SMTP Server) with ESMTPA ID 55a7229bea084bb6b28fa3beefd2f4cd; Tue, 27 Sep 2022 20:10:48 +0000 (UTC) From: Casey Schaufler To: casey.schaufler@intel.com, paul@paul-moore.com, linux-security-module@vger.kernel.org Cc: casey@schaufler-ca.com, linux-audit@redhat.com, jmorris@namei.org, selinux@vger.kernel.org, keescook@chromium.org, john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp, stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org Subject: [PATCH v38 32/39] Audit: Allow multiple records in an audit_buffer Date: Tue, 27 Sep 2022 12:54:14 -0700 Message-Id: <20220927195421.14713-33-casey@schaufler-ca.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220927195421.14713-1-casey@schaufler-ca.com> References: <20220927195421.14713-1-casey@schaufler-ca.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org Replace the single skb pointer in an audit_buffer with a list of skb pointers. Add the audit_stamp information to the audit_buffer as there's no guarantee that there will be an audit_context containing the stamp associated with the event. At audit_log_end() time create auxiliary records (none are currently defined) as have been added to the list. Functions are created to manage the skb list in the audit_buffer. Suggested-by: Paul Moore Signed-off-by: Casey Schaufler --- kernel/audit.c | 111 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 89 insertions(+), 22 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index 7facf6929f64..ef6b2d38e38d 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -197,8 +197,10 @@ static struct audit_ctl_mutex { * to place it on a transmit queue. Multiple audit_buffers can be in * use simultaneously. */ struct audit_buffer { - struct sk_buff *skb; /* formatted skb ready to send */ + struct sk_buff *skb; /* the skb for audit_log functions */ + struct sk_buff_head skb_list; /* formatted skbs, ready to send */ struct audit_context *ctx; /* NULL or associated context */ + struct audit_stamp stamp; /* audit stamp for these records */ gfp_t gfp_mask; }; @@ -1765,10 +1767,13 @@ __setup("audit_backlog_limit=", audit_backlog_limit_set); static void audit_buffer_free(struct audit_buffer *ab) { + struct sk_buff *skb; + if (!ab) return; - kfree_skb(ab->skb); + while ((skb = skb_dequeue(&ab->skb_list))) + kfree_skb(skb); kmem_cache_free(audit_buffer_cache, ab); } @@ -1784,6 +1789,10 @@ static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx, ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); if (!ab->skb) goto err; + + skb_queue_head_init(&ab->skb_list); + skb_queue_tail(&ab->skb_list, ab->skb); + if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0)) goto err; @@ -1849,7 +1858,6 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type) { struct audit_buffer *ab; - struct audit_stamp stamp; if (audit_initialized != AUDIT_INITIALIZED) return NULL; @@ -1904,14 +1912,14 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, return NULL; } - audit_get_stamp(ab->ctx, &stamp); + audit_get_stamp(ab->ctx, &ab->stamp); /* cancel dummy context to enable supporting records */ if (ctx) ctx->dummy = 0; audit_log_format(ab, "audit(%llu.%03lu:%u): ", - (unsigned long long)stamp.ctime.tv_sec, - stamp.ctime.tv_nsec/1000000, - stamp.serial); + (unsigned long long)ab->stamp.ctime.tv_sec, + ab->stamp.ctime.tv_nsec/1000000, + ab->stamp.serial); return ab; } @@ -2167,6 +2175,57 @@ void audit_log_key(struct audit_buffer *ab, char *key) audit_log_format(ab, "(null)"); } +/** + * audit_buffer_aux_new - Add an aux record buffer to the skb list + * @ab: audit_buffer + * @type: message type + * + * Aux records are allocated and added to the skb list of + * the "main" record. The ab->skb is reset to point to the + * aux record on its creation. When the aux record in complete + * ab->skb has to be reset to point to the "main" record. + * This allows the audit_log_ functions to be ignorant of + * which kind of record it is logging to. It also avoids adding + * special data for aux records. + * + * On success ab->skb will point to the new aux record. + * Returns 0 on success, -ENOMEM should allocation fail. + */ +static int audit_buffer_aux_new(struct audit_buffer *ab, int type) +{ + WARN_ON(ab->skb != skb_peek(&ab->skb_list)); + + ab->skb = nlmsg_new(AUDIT_BUFSIZ, ab->gfp_mask); + if (!ab->skb) + goto err; + if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0)) + goto err; + skb_queue_tail(&ab->skb_list, ab->skb); + + audit_log_format(ab, "audit(%llu.%03lu:%u): ", + (unsigned long long)ab->stamp.ctime.tv_sec, + ab->stamp.ctime.tv_nsec/1000000, + ab->stamp.serial); + + return 0; + +err: + kfree_skb(ab->skb); + ab->skb = skb_peek(&ab->skb_list); + return -ENOMEM; +} + +/** + * audit_buffer_aux_end - Switch back to the "main" record from an aux record + * @ab: audit_buffer + * + * Restores the "main" audit record to ab->skb. + */ +static void audit_buffer_aux_end(struct audit_buffer *ab) +{ + ab->skb = skb_peek(&ab->skb_list); +} + int audit_log_task_context(struct audit_buffer *ab) { int error; @@ -2402,26 +2461,14 @@ int audit_signal_info(int sig, struct task_struct *t) } /** - * audit_log_end - end one audit record - * @ab: the audit_buffer - * - * We can not do a netlink send inside an irq context because it blocks (last - * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a - * queue and a kthread is scheduled to remove them from the queue outside the - * irq context. May be called in any context. + * __audit_log_end - enqueue one audit record + * @skb: the buffer to send */ -void audit_log_end(struct audit_buffer *ab) +static void __audit_log_end(struct sk_buff *skb) { - struct sk_buff *skb; struct nlmsghdr *nlh; - if (!ab) - return; - if (audit_rate_check()) { - skb = ab->skb; - ab->skb = NULL; - /* setup the netlink header, see the comments in * kauditd_send_multicast_skb() for length quirks */ nlh = nlmsg_hdr(skb); @@ -2432,6 +2479,26 @@ void audit_log_end(struct audit_buffer *ab) wake_up_interruptible(&kauditd_wait); } else audit_log_lost("rate limit exceeded"); +} + +/** + * audit_log_end - end one audit record + * @ab: the audit_buffer + * + * We can not do a netlink send inside an irq context because it blocks (last + * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a + * queue and a kthread is scheduled to remove them from the queue outside the + * irq context. May be called in any context. + */ +void audit_log_end(struct audit_buffer *ab) +{ + struct sk_buff *skb; + + if (!ab) + return; + + while ((skb = skb_dequeue(&ab->skb_list))) + __audit_log_end(skb); audit_buffer_free(ab); }