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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 592D5C4332F for ; Tue, 26 Oct 2021 20:38:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4409B60EFF for ; Tue, 26 Oct 2021 20:38:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239241AbhJZUlB (ORCPT ); Tue, 26 Oct 2021 16:41:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239227AbhJZUlA (ORCPT ); Tue, 26 Oct 2021 16:41:00 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7DD8C061570; Tue, 26 Oct 2021 13:38:35 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id m26so601796pff.3; Tue, 26 Oct 2021 13:38:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=MRtccMdi1NGrZmESKfdGKtX5OHduZDH2rm/cokwWIs8=; b=MpezclMoLmUG/nEvApQ8jtm+U1hWVxqrP0cluiQreVvjRIAk6Gc1Lvq3ztZg4/iAcj dOB2iOeYUXHpqEZ7MP3aSTLgK/J9CTajf9P+RkgVIl+gucVNKl2a6eWYauMxj5ZI6gkx Qpu80r8uznzAZvGuN1hb8mzEDOZCwE9eFwbWHL28bnA+wuBUpNISB4vtxFLB23Ue7G/n 1fUzQUXRZjTG3ILLL4o7KmIP4LvyPw/70/X/Gh3PxkiEO50GP4KFzGvHECV5oB8ZrjT4 xz2uzB//OMhkuwTumk1dRDs+ABOksF+au6pTAg29kb585CdtuiolvGziOB00BbZNBX4n glJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=MRtccMdi1NGrZmESKfdGKtX5OHduZDH2rm/cokwWIs8=; b=e3aAuzR8vWzSOjmMPH4dXywV35KIty33PTH8OkdbGsuBAe+N5aqFDUVcUWyZNPhNLa 12AFJ3kekB17E6kTSiM6dUp1T1QP7J4hp/mUWvWFbC/bRbrv8PSr80wUFfAWCPyUwApE Ed30dBwEk29QYLjB/OwiMLhJrjbtwEqNy2q0YDCXBidxZn3CISSKqB65UxebcAzRGmGS U3ylab21JrRaimRdGXCVDR3TOEoR0E2t4UJN8E07tZDE+0M1MLMMi0niGgRVrnS2vmkp SjcgTTjMvEgJBJa/9fSy6WqiAX1sOfJzmZrtX9upIzot0NtV/bWwDyRXKKykFSVnYpKG 5b6w== X-Gm-Message-State: AOAM531Yj4FagyxKPoITZLmXYADOKCitK7lEl5ucySqQyb97ch1sisjA CvHyGckmmvv30R7yquMvTv4= X-Google-Smtp-Source: ABdhPJyRH0xqeonwoTBxjQCxhaQsoJAk/LlNymjEePUY/ElRHFa58JczzEDGGYaxeVcRjU1ToUyGfg== X-Received: by 2002:a05:6a00:1897:b0:47b:ff8c:3b05 with SMTP id x23-20020a056a00189700b0047bff8c3b05mr11924157pfh.37.1635280715469; Tue, 26 Oct 2021 13:38:35 -0700 (PDT) Received: from edumazet1.svl.corp.google.com ([2620:15c:2c4:201:207c:7102:7bd7:80eb]) by smtp.gmail.com with ESMTPSA id ip8sm1944477pjb.9.2021.10.26.13.38.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Oct 2021 13:38:35 -0700 (PDT) From: Eric Dumazet To: Alexei Starovoitov , Daniel Borkmann Cc: "David S . Miller" , netdev , Eric Dumazet , Eric Dumazet , bpf Subject: [PATCH bpf 2/2] bpf: fixes possible race in update_prog_stats() for 32bit arches Date: Tue, 26 Oct 2021 13:38:25 -0700 Message-Id: <20211026203825.2720459-3-eric.dumazet@gmail.com> X-Mailer: git-send-email 2.33.0.1079.g6e70778dc9-goog In-Reply-To: <20211026203825.2720459-1-eric.dumazet@gmail.com> References: <20211026203825.2720459-1-eric.dumazet@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Eric Dumazet It seems update_prog_stats() suffers from same issue fixed in the prior patch: As it can run while interrupts are enabled, it could be re-entered and the u64_stats syncp could be mangled. Fixes: fec56f5890d9 ("bpf: Introduce BPF trampoline") Signed-off-by: Eric Dumazet Cc: Alexei Starovoitov Cc: Daniel Borkmann --- kernel/bpf/trampoline.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index fe1e857324e6683cecf5f88d24e0790f7ec72253..d3a307a8c42b95692f082f23f01e1ed470e63dec 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -585,11 +585,13 @@ static void notrace update_prog_stats(struct bpf_prog *prog, * Hence check that 'start' is valid. */ start > NO_START_TIME) { + unsigned long flags; + stats = this_cpu_ptr(prog->stats); - u64_stats_update_begin(&stats->syncp); + flags = u64_stats_update_begin_irqsave(&stats->syncp); stats->cnt++; stats->nsecs += sched_clock() - start; - u64_stats_update_end(&stats->syncp); + u64_stats_update_end_irqrestore(&stats->syncp, flags); } } -- 2.33.0.1079.g6e70778dc9-goog