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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 EAE59C433DF for ; Tue, 9 Jun 2020 16:57:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C186720760 for ; Tue, 9 Jun 2020 16:57:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="tMvNXNJo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731220AbgFIQ5K (ORCPT ); Tue, 9 Jun 2020 12:57:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731061AbgFIQ5H (ORCPT ); Tue, 9 Jun 2020 12:57:07 -0400 Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AB69C05BD1E; Tue, 9 Jun 2020 09:57:07 -0700 (PDT) Received: by mail-io1-xd42.google.com with SMTP id m81so23586783ioa.1; Tue, 09 Jun 2020 09:57:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=5gvAS0s0tNpovI3i50BhHwoc6p3AStdG8TOtuxWup4w=; b=tMvNXNJopze0GqB5+EV+ftXRCWZBeAN6qu2GK8i13KXAnv+Byi7F93Bd+iVyKjBUNo hO9yhQtuT1sdzfHnZpuAfXsSNp+c2JhctcoXr5c2mXRhl8+CBg7Jx8OWxFccaBI9KnxL n2zqtjPDI5jwAFxNGB+OAWeU37COAvNIPl1jgVqy8mCiYJ1WIGtOBZIzQtOFBKDnY+Ah LCoH04OVGWmsD1y+/oKEc4h5p65ORFlJfEnUghZAySAR8HtYygyTr/+mqjzSeFClHedW wPAfikhEOotImnatbJaqQxq83Lf0sPc2zTERq0g1Dn//WhxPvQxFdGuY1T4cz2GBOwpr UM6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=5gvAS0s0tNpovI3i50BhHwoc6p3AStdG8TOtuxWup4w=; b=JJ9118HRxq49XaFOzBSaLzdvW5wuKw7rkjw/L5ajSATmr/FsWJiXq/p8RgJWJvbZVA YW4jqh1zNXOU0SXRvq5K0m0VGqJvlVIDSiRWUHNYb2Hcoceg1WgBZ4X8TXHHPTthpSjQ kxhsv19NZtafnpr8lE0N5QhYMRw2WOs4yRx/Rb/jGQKI2XhZmSCNHSAhY1tnaCRL2WDH mc6Gza0e8JmiTDjQgRDtUdc1homko5Jhc43ZshmVY0vc8T2fIIe3xGnJcHT+XDrmV6+/ 0jB9zBfWxDOfCCO/6ppKTyxWeD9gXUhsRorHKkP7JjeZUn8ShSF/VzZjhmccBDdqQb12 WDQg== X-Gm-Message-State: AOAM532Pikm+PT2FhTtSlMoJAX6hiKftLvIdRZ6OCO0pPs8bAPWpE3eF XdN3on/nzIm+RXEjWjnAyUQ= X-Google-Smtp-Source: ABdhPJxzfFNX5iPi6sdKo+Si6me8KJa4LoBVF4M8+UTrToEsXFwUCXTJ4+2Cezd7q2X79o0KK+1RsQ== X-Received: by 2002:a02:84c6:: with SMTP id f64mr27190470jai.25.1591721826490; Tue, 09 Jun 2020 09:57:06 -0700 (PDT) Received: from localhost ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id n7sm6721682ile.76.2020.06.09.09.57.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Jun 2020 09:57:05 -0700 (PDT) Date: Tue, 09 Jun 2020 09:56:56 -0700 From: John Fastabend To: Jakub Sitnicki , bpf@vger.kernel.org Cc: netdev@vger.kernel.org, kernel-team@cloudflare.com Message-ID: <5edfbf58f0ff1_5cca2af6a27f45b8fc@john-XPS-13-9370.notmuch> In-Reply-To: <20200607205229.2389672-2-jakub@cloudflare.com> References: <20200607205229.2389672-1-jakub@cloudflare.com> <20200607205229.2389672-2-jakub@cloudflare.com> Subject: RE: [PATCH bpf 1/2] bpf, sockhash: Fix memory leak when unlinking sockets in sock_hash_free Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Jakub Sitnicki wrote: > When sockhash gets destroyed while sockets are still linked to it, we will > walk the bucket lists and delete the links. However, we are not freeing the > list elements after processing them, leaking the memory. > > The leak can be triggered by close()'ing a sockhash map when it still > contains sockets, and observed with kmemleak: > > unreferenced object 0xffff888116e86f00 (size 64): > comm "race_sock_unlin", pid 223, jiffies 4294731063 (age 217.404s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 81 de e8 41 00 00 00 00 c0 69 2f 15 81 88 ff ff ...A.....i/..... > backtrace: > [<00000000dd089ebb>] sock_hash_update_common+0x4ca/0x760 > [<00000000b8219bd5>] sock_hash_update_elem+0x1d2/0x200 > [<000000005e2c23de>] __do_sys_bpf+0x2046/0x2990 > [<00000000d0084618>] do_syscall_64+0xad/0x9a0 > [<000000000d96f263>] entry_SYSCALL_64_after_hwframe+0x49/0xb3 > > Fix it by freeing the list element when we're done with it. > > Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") > Signed-off-by: Jakub Sitnicki > --- > net/core/sock_map.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/net/core/sock_map.c b/net/core/sock_map.c > index 00a26cf2cfe9..ea46f07a22d8 100644 > --- a/net/core/sock_map.c > +++ b/net/core/sock_map.c > @@ -1031,6 +1031,7 @@ static void sock_hash_free(struct bpf_map *map) > sock_map_unref(elem->sk, elem); > rcu_read_unlock(); > release_sock(elem->sk); > + sock_hash_free_elem(htab, elem); > } > } > > -- > 2.25.4 > In Cilium we pin the map and never release it thanks for catching this. Acked-by: John Fastabend