From patchwork Tue Apr 5 07:16:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 558212 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 E9EADC433EF for ; Tue, 5 Apr 2022 07:52:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231856AbiDEHxw (ORCPT ); Tue, 5 Apr 2022 03:53:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231984AbiDEHxV (ORCPT ); Tue, 5 Apr 2022 03:53:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6BF021D0FB; Tue, 5 Apr 2022 00:49:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8E2E9616DE; Tue, 5 Apr 2022 07:49:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96078C34111; Tue, 5 Apr 2022 07:49:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649144943; bh=cHlysSGxH3/ZHuRkBmnRpvSMKRf5BTYimY2JJA1trDs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u8JMfY3U/7rNHnDJ1PyQFdLP2AVwyf7sb21QlOXopsxG+bjAnOZp8msdzhk7HNQ8B grvSpw3p+NKFC1DYo3C3J83AdXnTGAiGkqapLTfczmm2foMJkpIDwTe9r5fpomf3Q4 neSurkqKeQYlV+sSvrnieMtIsb8xeGJ5gVY7dfL4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Richard Guy Briggs , Paul Moore , Sasha Levin Subject: [PATCH 5.17 0228/1126] audit: log AUDIT_TIME_* records only from rules Date: Tue, 5 Apr 2022 09:16:15 +0200 Message-Id: <20220405070414.301196183@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070407.513532867@linuxfoundation.org> References: <20220405070407.513532867@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Richard Guy Briggs [ Upstream commit 272ceeaea355214b301530e262a0df8600bfca95 ] AUDIT_TIME_* events are generated when there are syscall rules present that are not related to time keeping. This will produce noisy log entries that could flood the logs and hide events we really care about. Rather than immediately produce the AUDIT_TIME_* records, store the data in the context and log it at syscall exit time respecting the filter rules. Note: This eats the audit_buffer, unlike any others in show_special(). Please see https://bugzilla.redhat.com/show_bug.cgi?id=1991919 Fixes: 7e8eda734d30 ("ntp: Audit NTP parameters adjustment") Fixes: 2d87a0674bd6 ("timekeeping: Audit clock adjustments") Signed-off-by: Richard Guy Briggs [PM: fixed style/whitespace issues] Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- kernel/audit.h | 4 +++ kernel/auditsc.c | 87 +++++++++++++++++++++++++++++++++++++----------- 2 files changed, 71 insertions(+), 20 deletions(-) diff --git a/kernel/audit.h b/kernel/audit.h index c4498090a5bd..58b66543b4d5 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -201,6 +201,10 @@ struct audit_context { struct { char *name; } module; + struct { + struct audit_ntp_data ntp_data; + struct timespec64 tk_injoffset; + } time; }; int fds[2]; struct audit_proctitle proctitle; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index a83928cbdcb7..ea2ee1181921 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1340,6 +1340,53 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) from_kuid(&init_user_ns, name->fcap.rootid)); } +static void audit_log_time(struct audit_context *context, struct audit_buffer **ab) +{ + const struct audit_ntp_data *ntp = &context->time.ntp_data; + const struct timespec64 *tk = &context->time.tk_injoffset; + static const char * const ntp_name[] = { + "offset", + "freq", + "status", + "tai", + "tick", + "adjust", + }; + int type; + + if (context->type == AUDIT_TIME_ADJNTPVAL) { + for (type = 0; type < AUDIT_NTP_NVALS; type++) { + if (ntp->vals[type].newval != ntp->vals[type].oldval) { + if (!*ab) { + *ab = audit_log_start(context, + GFP_KERNEL, + AUDIT_TIME_ADJNTPVAL); + if (!*ab) + return; + } + audit_log_format(*ab, "op=%s old=%lli new=%lli", + ntp_name[type], + ntp->vals[type].oldval, + ntp->vals[type].newval); + audit_log_end(*ab); + *ab = NULL; + } + } + } + if (tk->tv_sec != 0 || tk->tv_nsec != 0) { + if (!*ab) { + *ab = audit_log_start(context, GFP_KERNEL, + AUDIT_TIME_INJOFFSET); + if (!*ab) + return; + } + audit_log_format(*ab, "sec=%lli nsec=%li", + (long long)tk->tv_sec, tk->tv_nsec); + audit_log_end(*ab); + *ab = NULL; + } +} + static void show_special(struct audit_context *context, int *call_panic) { struct audit_buffer *ab; @@ -1454,6 +1501,11 @@ static void show_special(struct audit_context *context, int *call_panic) audit_log_format(ab, "(null)"); break; + case AUDIT_TIME_ADJNTPVAL: + case AUDIT_TIME_INJOFFSET: + /* this call deviates from the rest, eating the buffer */ + audit_log_time(context, &ab); + break; } audit_log_end(ab); } @@ -2849,31 +2901,26 @@ void __audit_fanotify(unsigned int response) void __audit_tk_injoffset(struct timespec64 offset) { - audit_log(audit_context(), GFP_KERNEL, AUDIT_TIME_INJOFFSET, - "sec=%lli nsec=%li", - (long long)offset.tv_sec, offset.tv_nsec); -} - -static void audit_log_ntp_val(const struct audit_ntp_data *ad, - const char *op, enum audit_ntp_type type) -{ - const struct audit_ntp_val *val = &ad->vals[type]; - - if (val->newval == val->oldval) - return; + struct audit_context *context = audit_context(); - audit_log(audit_context(), GFP_KERNEL, AUDIT_TIME_ADJNTPVAL, - "op=%s old=%lli new=%lli", op, val->oldval, val->newval); + /* only set type if not already set by NTP */ + if (!context->type) + context->type = AUDIT_TIME_INJOFFSET; + memcpy(&context->time.tk_injoffset, &offset, sizeof(offset)); } void __audit_ntp_log(const struct audit_ntp_data *ad) { - audit_log_ntp_val(ad, "offset", AUDIT_NTP_OFFSET); - audit_log_ntp_val(ad, "freq", AUDIT_NTP_FREQ); - audit_log_ntp_val(ad, "status", AUDIT_NTP_STATUS); - audit_log_ntp_val(ad, "tai", AUDIT_NTP_TAI); - audit_log_ntp_val(ad, "tick", AUDIT_NTP_TICK); - audit_log_ntp_val(ad, "adjust", AUDIT_NTP_ADJUST); + struct audit_context *context = audit_context(); + int type; + + for (type = 0; type < AUDIT_NTP_NVALS; type++) + if (ad->vals[type].newval != ad->vals[type].oldval) { + /* unconditionally set type, overwriting TK */ + context->type = AUDIT_TIME_ADJNTPVAL; + memcpy(&context->time.ntp_data, ad, sizeof(*ad)); + break; + } } void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,