From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D2F5406274 for ; Tue, 24 Mar 2026 15:19:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774365559; cv=none; b=iI9na2B2g5H7hZFztuEX6ovDEiNRiJ3H9c173FhpkxgrFN27BPkrOeMT4VEbGHLQyqzaHbDXjntrIqJi9HosHFzhUnonP6SXk95NGFsCFMrN46k5khtPaaePB0nX7aoihAgK8og+UrlL2O1BqTwcx2+tTDCgkGAOGWd5bTyVLmE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774365559; c=relaxed/simple; bh=yQu+yg14FNYHLy+s+BbhOlgj6hTn6x3xR7kw0ed5ygA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oY0S1C9IlTmCQmPWOE2VYULXStvA/W8J4D2NAFI6fv1mMAGfkUroXnlZWAbxVUeMGa7vqyfDRjQbzzRsLlyhDhXUOE1O93a79xc2FJ+x1yUuHI2BhAuDmiQojg5qI0/q85hqwNM+RUPPcWY6OpGdxpLBLnuZcSeRgqb26sdzm1I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=DgZTSMk8; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DgZTSMk8" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774365555; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=47K4ukq6ERapPLsJPgxXf1k9UvvwaRytR4+a7cgPSYw=; b=DgZTSMk8MUQwgAX1/wPeE5pBySz9IhkNrmfu9Y4t/noRwZpAVR6aLBqAXGB7IbAk18j2xh s3T0csefPxFehSgU5jxtVKMGFWyuZiQ9zM8yqdceQJHasgxVVqehcjQ/zJHp87VjyCTBuL agYBmver4BNqwR4PlFNqNff3xxHMTYA= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-265-fwC_8vFtNWuKSKRWqW9RmQ-1; Tue, 24 Mar 2026 11:19:11 -0400 X-MC-Unique: fwC_8vFtNWuKSKRWqW9RmQ-1 X-Mimecast-MFC-AGG-ID: fwC_8vFtNWuKSKRWqW9RmQ_1774365549 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E95361956046; Tue, 24 Mar 2026 15:19:08 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.65.192]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8BBCA1800764; Tue, 24 Mar 2026 15:19:04 +0000 (UTC) From: Waiman Long To: Simon Horman , Julian Anastasov , "David S. Miller" , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Pablo Neira Ayuso , Florian Westphal , Phil Sutter , Frederic Weisbecker , Chen Ridong , Phil Auld Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, lvs-devel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, sheviks , Waiman Long Subject: [PATCH 2/2] ipvs: Guard access of HK_TYPE_KTHREAD cpumask with RCU Date: Tue, 24 Mar 2026 11:18:27 -0400 Message-ID: <20260324151827.2006656-3-longman@redhat.com> In-Reply-To: <20260324151827.2006656-1-longman@redhat.com> References: <20260324151827.2006656-1-longman@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 The ip_vs_ctl.c file and the associated ip_vs.h file are the only places in the kernel where HK_TYPE_KTHREAD cpumask is being retrieved and used. Now that HK_TYPE_KTHREAD/HK_TYPE_DOMAIN cpumask can be changed at run time. We need to use RCU to guard access to this cpumask to avoid a potential UAF problem as the returned cpumask may be freed before it is being used. Signed-off-by: Waiman Long --- include/net/ip_vs.h | 20 ++++++++++++++++---- net/netfilter/ipvs/ip_vs_ctl.c | 13 ++++++++----- 2 files changed, 24 insertions(+), 9 deletions(-) diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 29a36709e7f3..17c85a575ef4 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -1155,7 +1155,7 @@ static inline int sysctl_run_estimation(struct netns_ipvs *ipvs) return ipvs->sysctl_run_estimation; } -static inline const struct cpumask *sysctl_est_cpulist(struct netns_ipvs *ipvs) +static inline const struct cpumask *__sysctl_est_cpulist(struct netns_ipvs *ipvs) { if (ipvs->est_cpulist_valid) return ipvs->sysctl_est_cpulist; @@ -1273,7 +1273,7 @@ static inline int sysctl_run_estimation(struct netns_ipvs *ipvs) return 1; } -static inline const struct cpumask *sysctl_est_cpulist(struct netns_ipvs *ipvs) +static inline const struct cpumask *__sysctl_est_cpulist(struct netns_ipvs *ipvs) { return housekeeping_cpumask(HK_TYPE_KTHREAD); } @@ -1290,6 +1290,18 @@ static inline int sysctl_est_nice(struct netns_ipvs *ipvs) #endif +static inline bool sysctl_est_cpulist_empty(struct netns_ipvs *ipvs) +{ + guard(rcu)(); + return cpumask_empty(__sysctl_est_cpulist(ipvs)); +} + +static inline unsigned int sysctl_est_cpulist_weight(struct netns_ipvs *ipvs) +{ + guard(rcu)(); + return cpumask_weight(__sysctl_est_cpulist(ipvs)); +} + /* IPVS core functions * (from ip_vs_core.c) */ @@ -1604,7 +1616,7 @@ static inline void ip_vs_est_stopped_recalc(struct netns_ipvs *ipvs) /* Stop tasks while cpulist is empty or if disabled with flag */ ipvs->est_stopped = !sysctl_run_estimation(ipvs) || (ipvs->est_cpulist_valid && - cpumask_empty(sysctl_est_cpulist(ipvs))); + sysctl_est_cpulist_empty(ipvs)); #endif } @@ -1620,7 +1632,7 @@ static inline bool ip_vs_est_stopped(struct netns_ipvs *ipvs) static inline int ip_vs_est_max_threads(struct netns_ipvs *ipvs) { unsigned int limit = IPVS_EST_CPU_KTHREADS * - cpumask_weight(sysctl_est_cpulist(ipvs)); + sysctl_est_cpulist_weight(ipvs); return max(1U, limit); } diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 35642de2a0fe..f38a2e2a9dc5 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1973,11 +1973,14 @@ static int ipvs_proc_est_cpumask_get(const struct ctl_table *table, mutex_lock(&ipvs->est_mutex); - if (ipvs->est_cpulist_valid) - mask = *valp; - else - mask = (struct cpumask *)housekeeping_cpumask(HK_TYPE_KTHREAD); - ret = scnprintf(buffer, size, "%*pbl\n", cpumask_pr_args(mask)); + /* HK_TYPE_KTHREAD cpumask needs RCU protection */ + scoped_guard(rcu) { + if (ipvs->est_cpulist_valid) + mask = *valp; + else + mask = (struct cpumask *)housekeeping_cpumask(HK_TYPE_KTHREAD); + ret = scnprintf(buffer, size, "%*pbl\n", cpumask_pr_args(mask)); + } mutex_unlock(&ipvs->est_mutex); -- 2.53.0