From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030443AbeBNORn (ORCPT ); Wed, 14 Feb 2018 09:17:43 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58588 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1030288AbeBNORl (ORCPT ); Wed, 14 Feb 2018 09:17:41 -0500 From: Jason Wang To: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: mst@redhat.com, Jason Wang , Michal Hocko , Matthew Wilcox , Jesper Dangaard Brouer , akpm@linux-foundation.org, dhowells@redhat.com, hannes@cmpxchg.org Subject: [PATCH net] bpf: cpumap: use GFP_KERNEL instead of GFP_ATOMIC in __cpu_map_entry_alloc() Date: Wed, 14 Feb 2018 22:17:34 +0800 Message-Id: <1518617854-4486-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There're several implications after commit 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails") with the using of vmalloc() since can't allow GFP_ATOMIC but mandate GFP_KERNEL. This will lead a WARN since cpumap try to call with GFP_ATOMIC. Fortunately, entry allocation of cpumap can only be done through syscall path which means GFP_ATOMIC is not necessary, so fixing this by replacing GFP_ATOMIC with GFP_KERNEL. Reported-by: syzbot+1a240cdb1f4cc88819df@syzkaller.appspotmail.com Fixes: 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails") Cc: Michal Hocko Cc: Daniel Borkmann Cc: Matthew Wilcox Cc: Jesper Dangaard Brouer Cc: akpm@linux-foundation.org Cc: dhowells@redhat.com Cc: hannes@cmpxchg.org Signed-off-by: Jason Wang --- kernel/bpf/cpumap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index fbfdada6..a4bb0b3 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -334,7 +334,7 @@ static int cpu_map_kthread_run(void *data) static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu, int map_id) { - gfp_t gfp = GFP_ATOMIC|__GFP_NOWARN; + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; struct bpf_cpu_map_entry *rcpu; int numa, err; -- 2.7.4