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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_NEOMUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BF77C43381 for ; Sat, 30 Mar 2019 12:55:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1C152183F for ; Sat, 30 Mar 2019 12:55:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730779AbfC3Mzv (ORCPT ); Sat, 30 Mar 2019 08:55:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33768 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730689AbfC3Mzv (ORCPT ); Sat, 30 Mar 2019 08:55:51 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EAFC281DF3; Sat, 30 Mar 2019 12:55:49 +0000 (UTC) Received: from madcap2.tricolour.ca (ovpn-112-19.phx2.redhat.com [10.3.112.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EECA41A7D4; Sat, 30 Mar 2019 12:55:38 +0000 (UTC) Date: Sat, 30 Mar 2019 08:55:36 -0400 From: Richard Guy Briggs To: Ondrej Mosnacek Cc: containers@lists.linux-foundation.org, linux-api@vger.kernel.org, Linux-Audit Mailing List , linux-fsdevel@vger.kernel.org, LKML , netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, Paul Moore , Steve Grubb , David Howells , Simo Sorce , Eric Paris , "Serge E. Hallyn" , "Eric W . Biederman" , nhorman@tuxdriver.com Subject: Re: [PATCH ghak90 V5 05/10] audit: add containerid support for ptrace and signals Message-ID: <20190330125536.mipbgw2hjewz3zem@madcap2.tricolour.ca> References: <20190328020410.pl7odjknw7robdk3@madcap2.tricolour.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190328020410.pl7odjknw7robdk3@madcap2.tricolour.ca> User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Sat, 30 Mar 2019 12:55:50 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2019-03-27 22:04, Richard Guy Briggs wrote: > On 2019-03-27 22:17, Ondrej Mosnacek wrote: > > On Fri, Mar 15, 2019 at 7:34 PM Richard Guy Briggs wrote: > > > Add audit container identifier support to ptrace and signals. In > > > particular, the "ref" field provides a way to label the auxiliary record > > > to which it is associated. > > > > > > Signed-off-by: Richard Guy Briggs > > > Acked-by: Serge Hallyn > > > Signed-off-by: Richard Guy Briggs > > > --- > > > include/linux/audit.h | 1 + > > > kernel/audit.c | 2 ++ > > > kernel/audit.h | 2 ++ > > > kernel/auditsc.c | 23 +++++++++++++++++------ > > > 4 files changed, 22 insertions(+), 6 deletions(-) > > > > > > diff --git a/include/linux/audit.h b/include/linux/audit.h > > > index 43438192ca2a..ebd6625ca80e 100644 > > > --- a/include/linux/audit.h > > > +++ b/include/linux/audit.h > > > @@ -35,6 +35,7 @@ struct audit_sig_info { > > > uid_t uid; > > > pid_t pid; > > > char ctx[0]; > > > + u64 cid; > > > }; > > > > It seems like this structure implicitly defines the format of some > > message that is sent to userspace... If so, how will userspace detect > > that a new format (including the cid) is being used? Even assuming the > > fixed order as pointed out by Neil, the message still seems to be > > variable-sized so userspace cannot even use the length to infer that. > > Am I missing something here? (I hope I am :) > > How humble of you again. No, you're not missing something. This ends > up being an api change... That can be fixed in userspace by checking > for AUDIT_FEATURE_BITMAP_CONTAINERID, but how do we make a newer kernel > not break an older userspace... I think this was the original rationale > for adding it after the ctx but totally missing the fact that the latter > is a variable-length field. The way to address this on Steve Grubb's advice is to create a new message type that incorporates a new struct with the structure above, leaving the old one with the old message type deprecated. I've coded this up along with userspace support. > This patch really should be split into audit_sig_cid changes in a patch > by itself and target_cid changes which could go with the second and > fourth patches. I've also done this which Paul had already asked for, not quite in this form. I believe this addresses all the outstanding issues. > > > struct audit_buffer; > > > diff --git a/kernel/audit.c b/kernel/audit.c > > > index 8cc0e88d7f2a..cfa659b3f6c4 100644 > > > --- a/kernel/audit.c > > > +++ b/kernel/audit.c > > > @@ -138,6 +138,7 @@ struct audit_net { > > > kuid_t audit_sig_uid = INVALID_UID; > > > pid_t audit_sig_pid = -1; > > > u32 audit_sig_sid = 0; > > > +u64 audit_sig_cid = AUDIT_CID_UNSET; > > > > > > /* Records can be lost in several ways: > > > 0) [suppressed in audit_alloc] > > > @@ -1515,6 +1516,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) > > > memcpy(sig_data->ctx, ctx, len); > > > security_release_secctx(ctx, len); > > > } > > > + sig_data->cid = audit_sig_cid; > > > audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, > > > sig_data, sizeof(*sig_data) + len); > > > kfree(sig_data); > > > diff --git a/kernel/audit.h b/kernel/audit.h > > > index c00e2ee3c6b3..c5ac6436317e 100644 > > > --- a/kernel/audit.h > > > +++ b/kernel/audit.h > > > @@ -148,6 +148,7 @@ struct audit_context { > > > kuid_t target_uid; > > > unsigned int target_sessionid; > > > u32 target_sid; > > > + u64 target_cid; > > > char target_comm[TASK_COMM_LEN]; > > > > > > struct audit_tree_refs *trees, *first_trees; > > > @@ -344,6 +345,7 @@ extern void audit_filter_inodes(struct task_struct *tsk, > > > extern pid_t audit_sig_pid; > > > extern kuid_t audit_sig_uid; > > > extern u32 audit_sig_sid; > > > +extern u64 audit_sig_cid; > > > > > > extern int audit_filter(int msgtype, unsigned int listtype); > > > > > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c > > > index a8c8b44b954d..f04e115df5dc 100644 > > > --- a/kernel/auditsc.c > > > +++ b/kernel/auditsc.c > > > @@ -113,6 +113,7 @@ struct audit_aux_data_pids { > > > kuid_t target_uid[AUDIT_AUX_PIDS]; > > > unsigned int target_sessionid[AUDIT_AUX_PIDS]; > > > u32 target_sid[AUDIT_AUX_PIDS]; > > > + u64 target_cid[AUDIT_AUX_PIDS]; > > > char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN]; > > > int pid_count; > > > }; > > > @@ -1514,7 +1515,7 @@ static void audit_log_exit(void) > > > for (aux = context->aux_pids; aux; aux = aux->next) { > > > struct audit_aux_data_pids *axs = (void *)aux; > > > > > > - for (i = 0; i < axs->pid_count; i++) > > > + for (i = 0; i < axs->pid_count; i++) { > > > if (audit_log_pid_context(context, axs->target_pid[i], > > > axs->target_auid[i], > > > axs->target_uid[i], > > > @@ -1522,14 +1523,20 @@ static void audit_log_exit(void) > > > axs->target_sid[i], > > > axs->target_comm[i])) > > > call_panic = 1; > > > + audit_log_contid(context, axs->target_cid[i]); > > > + } > > > } > > > > > > - if (context->target_pid && > > > - audit_log_pid_context(context, context->target_pid, > > > - context->target_auid, context->target_uid, > > > - context->target_sessionid, > > > - context->target_sid, context->target_comm)) > > > + if (context->target_pid) { > > > + if (audit_log_pid_context(context, context->target_pid, > > > + context->target_auid, > > > + context->target_uid, > > > + context->target_sessionid, > > > + context->target_sid, > > > + context->target_comm)) > > > call_panic = 1; > > > + audit_log_contid(context, context->target_cid); > > > + } > > > > > > if (context->pwd.dentry && context->pwd.mnt) { > > > ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD); > > > @@ -2360,6 +2367,7 @@ void __audit_ptrace(struct task_struct *t) > > > context->target_uid = task_uid(t); > > > context->target_sessionid = audit_get_sessionid(t); > > > security_task_getsecid(t, &context->target_sid); > > > + context->target_cid = audit_get_contid(t); > > > memcpy(context->target_comm, t->comm, TASK_COMM_LEN); > > > } > > > > > > @@ -2387,6 +2395,7 @@ int audit_signal_info(int sig, struct task_struct *t) > > > else > > > audit_sig_uid = uid; > > > security_task_getsecid(current, &audit_sig_sid); > > > + audit_sig_cid = audit_get_contid(current); > > > } > > > > > > if (!audit_signals || audit_dummy_context()) > > > @@ -2400,6 +2409,7 @@ int audit_signal_info(int sig, struct task_struct *t) > > > ctx->target_uid = t_uid; > > > ctx->target_sessionid = audit_get_sessionid(t); > > > security_task_getsecid(t, &ctx->target_sid); > > > + ctx->target_cid = audit_get_contid(t); > > > memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN); > > > return 0; > > > } > > > @@ -2421,6 +2431,7 @@ int audit_signal_info(int sig, struct task_struct *t) > > > axp->target_uid[axp->pid_count] = t_uid; > > > axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t); > > > security_task_getsecid(t, &axp->target_sid[axp->pid_count]); > > > + axp->target_cid[axp->pid_count] = audit_get_contid(t); > > > memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN); > > > axp->pid_count++; > > > > > > > Ondrej Mosnacek > > - RGB - RGB -- Richard Guy Briggs Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635