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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 DA876C43381 for ; Wed, 13 Mar 2019 09:39:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A24E02173C for ; Wed, 13 Mar 2019 09:39:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727417AbfCMJj4 (ORCPT ); Wed, 13 Mar 2019 05:39:56 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:34566 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726163AbfCMJjz (ORCPT ); Wed, 13 Mar 2019 05:39:55 -0400 Received: by mail-wr1-f67.google.com with SMTP id k1so635155wre.1 for ; Wed, 13 Mar 2019 02:39:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=ZAfyPnPwU+aczkaOtPySrtBjNpg9q9U80NEjrzP4wfI=; b=HvQ8L8cMnxfI/QY+pYsSbsEHoOk3FOOYFjqvs3uArCzfu8LfSI7u8f6qikurodtMJo XWKzo1EwkRK81e1dNTh+RP1XasDMT782QV7jPAr8wzahjnuLuKRqW0uBH8ToD8kb6gbA lr/lv8vWR/KnsRvn5THqEuoS5YZDGEGv70vcvc8SAoEdtRFhFvspTUpdqFI2Cd+C1zqN rpxBZ14HNhTPADLEgpyBr3qtiiwGlV2JMcQZ8MeHcfk4pfY6pq/ahFvpZb7SEkGaXcWv bvSOS6wDgpjmXGnX9ZV5EIEuufIcgFkJo4w9mywIUL55KtiiR0DzKUEp+LFmhIKJ+nlv 9rAA== X-Gm-Message-State: APjAAAVDxDGQ2AB8tPXJ23JG5mLEIFGIkKuxFnKMjI0jTXIBUZJmwzRV kA4A8IvqVw+vSPDVSxyH7EQ= X-Google-Smtp-Source: APXvYqyi2CsndZ6tlYEDwa8aR7XgzZYB1JB3V20tDV/Gqv21qo6b0GVIZvOihHKwYweiFMq3L6vRSw== X-Received: by 2002:a05:6000:4e:: with SMTP id k14mr4241258wrx.52.1552469993600; Wed, 13 Mar 2019 02:39:53 -0700 (PDT) Received: from ?IPv6:2a0b:e7c0:0:107::49? ([2a0b:e7c0:0:107::49]) by smtp.gmail.com with ESMTPSA id 12sm3830187wme.25.2019.03.13.02.39.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 13 Mar 2019 02:39:52 -0700 (PDT) Subject: Re: [bpf-next,02/11] xsk: introduce xdp_umem_page To: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , magnus.karlsson@intel.com, magnus.karlsson@gmail.com, alexander.h.duyck@intel.com, alexander.duyck@gmail.com, ast@fb.com, brouer@redhat.com, daniel@iogearbox.net, netdev@vger.kernel.org, mykyta.iziumtsev@linaro.org Cc: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , john.fastabend@gmail.com, willemdebruijn.kernel@gmail.com, mst@redhat.com, michael.lundkvist@ericsson.com, jesse.brandeburg@intel.com, anjali.singhai@intel.com, qi.z.zhang@intel.com, francois.ozog@linaro.org, ilias.apalodimas@linaro.org, brian.brooks@linaro.org, andy@greyhouse.net, michael.chan@broadcom.com, intel-wired-lan@lists.osuosl.org References: <20180604120601.18123-3-bjorn.topel@gmail.com> From: Jiri Slaby Openpgp: preference=signencrypt Autocrypt: addr=jslaby@suse.cz; prefer-encrypt=mutual; keydata= mQINBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABtBtKaXJpIFNsYWJ5 IDxqc2xhYnlAc3VzZS5jej6JAjgEEwECACIFAk6S6NgCGwMGCwkIBwMCBhUIAgkKCwQWAgMB Ah4BAheAAAoJEL0lsQQGtHBJgDsP/j9wh0vzWXsOPO3rDpHjeC3BT5DKwjVN/KtP7uZttlkB duReCYMTZGzSrmK27QhCflZ7Tw0Naq4FtmQSH8dkqVFugirhlCOGSnDYiZAAubjTrNLTqf7e 5poQxE8mmniH/Asg4KufD9bpxSIi7gYIzaY3hqvYbVF1vYwaMTujojlixvesf0AFlE4x8WKs wpk43fmo0ZLcwObTnC3Hl1JBsPujCVY8t4E7zmLm7kOB+8EHaHiRZ4fFDWweuTzRDIJtVmrH LWvRDAYg+IH3SoxtdJe28xD9KoJw4jOX1URuzIU6dklQAnsKVqxz/rpp1+UVV6Ky6OBEFuoR 613qxHCFuPbkRdpKmHyE0UzmniJgMif3v0zm/+1A/VIxpyN74cgwxjhxhj/XZWN/LnFuER1W zTHcwaQNjq/I62AiPec5KgxtDeV+VllpKmFOtJ194nm9QM9oDSRBMzrG/2AY/6GgOdZ0+qe+ 4BpXyt8TmqkWHIsVpE7I5zVDgKE/YTyhDuqYUaWMoI19bUlBBUQfdgdgSKRMJX4vE72dl8BZ +/ONKWECTQ0hYntShkmdczcUEsWjtIwZvFOqgGDbev46skyakWyod6vSbOJtEHmEq04NegUD al3W7Y/FKSO8NqcfrsRNFWHZ3bZ2Q5X0tR6fc6gnZkNEtOm5fcWLY+NVz4HLaKrJuQINBE6S 54YBEADPnA1iy/lr3PXC4QNjl2f4DJruzW2Co37YdVMjrgXeXpiDvneEXxTNNlxUyLeDMcIQ K8obCkEHAOIkDZXZG8nr4mKzyloy040V0+XA9paVs6/ice5l+yJ1eSTs9UKvj/pyVmCAY1Co SNN7sfPaefAmIpduGacp9heXF+1Pop2PJSSAcCzwZ3PWdAJ/w1Z1Dg/tMCHGFZ2QCg4iFzg5 Bqk4N34WcG24vigIbRzxTNnxsNlU1H+tiB81fngUp2pszzgXNV7CWCkaNxRzXi7kvH+MFHu2 1m/TuujzxSv0ZHqjV+mpJBQX/VX62da0xCgMidrqn9RCNaJWJxDZOPtNCAWvgWrxkPFFvXRl t52z637jleVFL257EkMI+u6UnawUKopa+Tf+R/c+1Qg0NHYbiTbbw0pU39olBQaoJN7JpZ99 T1GIlT6zD9FeI2tIvarTv0wdNa0308l00bas+d6juXRrGIpYiTuWlJofLMFaaLYCuP+e4d8x rGlzvTxoJ5wHanilSE2hUy2NSEoPj7W+CqJYojo6wTJkFEiVbZFFzKwjAnrjwxh6O9/V3O+Z XB5RrjN8hAf/4bSo8qa2y3i39cuMT8k3nhec4P9M7UWTSmYnIBJsclDQRx5wSh0Mc9Y/psx9 B42WbV4xrtiiydfBtO6tH6c9mT5Ng+d1sN/VTSPyfQARAQABiQIfBBgBAgAJBQJOkueGAhsM AAoJEL0lsQQGtHBJN7UQAIDvgxaW8iGuEZZ36XFtewH56WYvVUefs6+Pep9ox/9ZXcETv0vk DUgPKnQAajG/ViOATWqADYHINAEuNvTKtLWmlipAI5JBgE+5g9UOT4i69OmP/is3a/dHlFZ3 qjNk1EEGyvioeycJhla0RjakKw5PoETbypxsBTXk5EyrSdD/I2Hez9YGW/RcI/WC8Y4Z/7FS ITZhASwaCOzy/vX2yC6iTx4AMFt+a6Z6uH/xGE8pG5NbGtd02r+m7SfuEDoG3Hs1iMGecPyV XxCVvSV6dwRQFc0UOZ1a6ywwCWfGOYqFnJvfSbUiCMV8bfRSWhnNQYLIuSv/nckyi8CzCYIg c21cfBvnwiSfWLZTTj1oWyj5a0PPgGOdgGoIvVjYXul3yXYeYOqbYjiC5t99JpEeIFupxIGV ciMk6t3pDrq7n7Vi/faqT+c4vnjazJi0UMfYnnAzYBa9+NkfW0w5W9Uy7kW/v7SffH/2yFiK 9HKkJqkN9xYEYaxtfl5pelF8idoxMZpTvCZY7jhnl2IemZCBMs6s338wS12Qro5WEAxV6cjD VSdmcD5l9plhKGLmgVNCTe8DPv81oDn9s0cIRLg9wNnDtj8aIiH8lBHwfUkpn32iv0uMV6Ae sLxhDWfOR4N+wu1gzXWgLel4drkCJcuYK5IL1qaZDcuGR8RPo3jbFO7Y Message-ID: Date: Wed, 13 Mar 2019 10:39:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.2 MIME-Version: 1.0 In-Reply-To: <20180604120601.18123-3-bjorn.topel@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 04. 06. 18, 14:05, Björn Töpel wrote: > From: Björn Töpel > > The xdp_umem_page holds the address for a page. Trade memory for > faster lookup. Later, we'll add DMA address here as well. ... > --- a/include/net/xdp_sock.h > +++ b/include/net/xdp_sock.h ... > --- a/net/xdp/xdp_umem.c > +++ b/net/xdp/xdp_umem.c > @@ -65,6 +65,9 @@ static void xdp_umem_release(struct xdp_umem *umem) > goto out; > > mmput(mm); > + kfree(umem->pages); > + umem->pages = NULL; > + Are you sure about the placement of kfree here? Why is it dependent on task && mm above? IMO the kfree should be below "out:": > xdp_umem_unaccount_pages(umem); > out: > kfree(umem); Syzkaller reported this memleak: r0 = socket$xdp(0x2c, 0x3, 0x0) setsockopt$XDP_UMEM_REG(r0, 0x11b, 0x4, &(0x7f0000000100)={&(0x7f0000000000)=""/210, 0x20000, 0x1000, 0x7}, 0x18) BUG: memory leak unreferenced object 0xffff88003648de68 (size 512): comm "syz-executor.3", pid 11688, jiffies 4295555546 (age 15.752s) hex dump (first 32 bytes): 00 00 40 23 00 88 ff ff 00 00 00 00 00 00 00 00 ..@#............ 00 10 40 23 00 88 ff ff 00 00 00 00 00 00 00 00 ..@#............ backtrace: [] xsk_setsockopt+0x40c/0x510 net/xdp/xsk.c:539 [] SyS_setsockopt+0x171/0x370 net/socket.c:1862 [] do_syscall_64+0x26c/0x6e0 arch/x86/entry/common.c:284 [] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [] 0xffffffffffffffff Given the size of the leak, it looks like umem->pages is leaked: mr->len/page_size*sizeof(*umem->pages) 0x20000/4096*16=512 So I added a check, and really, task is NULL in my testcase -- the program is gone when the deferred work triggers. But umem->pages is not freed. Moving the free after "out:", no leaks happen anymore. Easily reproducible with: #include #include #include #include #include #include #include void fun() { static char buffer[0x20000] __attribute__((aligned(4096))); struct xdp_umem_reg mr = { (unsigned long)buffer, 0x20000, 0x1000, 0x7, //&(0x7f0000000100)={&(0x7f0000000000)=""/210, 0x20000, 0x1000, 0x7} }; int r0; r0 = socket(AF_XDP, SOCK_RAW, 0); if (r0 < 0) err(1, "socket"); if (setsockopt(r0, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr)) < 0) err(1, "setsockopt"); close(r0); } int main() { int a; while (1) { for (a = 0; a < 40; a++) if (!fork()) { fun(); exit(0); } for (a = 0; a < 100; a++) wait(NULL); } } thanks, -- js suse labs