From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45008 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726275AbeIREUq (ORCPT ); Tue, 18 Sep 2018 00:20:46 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Hocko , Mel Gorman , Paul Moore , Amit Pundir Subject: [PATCH 4.4 11/56] selinux: use GFP_NOWAIT in the AVC kmem_caches Date: Tue, 18 Sep 2018 00:41:44 +0200 Message-Id: <20180917213828.433882553@linuxfoundation.org> In-Reply-To: <20180917213827.913122591@linuxfoundation.org> References: <20180917213827.913122591@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michal Hocko commit 476accbe2f6ef69caeebe99f52a286e12ac35aee upstream. There is a strange __GFP_NOMEMALLOC usage pattern in SELinux, specifically GFP_ATOMIC | __GFP_NOMEMALLOC which doesn't make much sense. GFP_ATOMIC on its own allows to access memory reserves while __GFP_NOMEMALLOC dictates we cannot use memory reserves. Replace this with the much more sane GFP_NOWAIT in the AVC code as we can tolerate memory allocation failures in that code. Signed-off-by: Michal Hocko Acked-by: Mel Gorman Signed-off-by: Paul Moore Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- security/selinux/avc.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -348,27 +348,26 @@ static struct avc_xperms_decision_node struct avc_xperms_decision_node *xpd_node; struct extended_perms_decision *xpd; - xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, - GFP_ATOMIC | __GFP_NOMEMALLOC); + xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, GFP_NOWAIT); if (!xpd_node) return NULL; xpd = &xpd_node->xpd; if (which & XPERMS_ALLOWED) { xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep, - GFP_ATOMIC | __GFP_NOMEMALLOC); + GFP_NOWAIT); if (!xpd->allowed) goto error; } if (which & XPERMS_AUDITALLOW) { xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep, - GFP_ATOMIC | __GFP_NOMEMALLOC); + GFP_NOWAIT); if (!xpd->auditallow) goto error; } if (which & XPERMS_DONTAUDIT) { xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep, - GFP_ATOMIC | __GFP_NOMEMALLOC); + GFP_NOWAIT); if (!xpd->dontaudit) goto error; } @@ -396,8 +395,7 @@ static struct avc_xperms_node *avc_xperm { struct avc_xperms_node *xp_node; - xp_node = kmem_cache_zalloc(avc_xperms_cachep, - GFP_ATOMIC|__GFP_NOMEMALLOC); + xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT); if (!xp_node) return xp_node; INIT_LIST_HEAD(&xp_node->xpd_head); @@ -550,7 +548,7 @@ static struct avc_node *avc_alloc_node(v { struct avc_node *node; - node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC|__GFP_NOMEMALLOC); + node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT); if (!node) goto out;