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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable 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 D8B7BC433E0 for ; Mon, 1 Mar 2021 13:41:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0AEF64DAF for ; Mon, 1 Mar 2021 13:41:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235866AbhCANl0 (ORCPT ); Mon, 1 Mar 2021 08:41:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235676AbhCANlT (ORCPT ); Mon, 1 Mar 2021 08:41:19 -0500 Received: from mail-lj1-x233.google.com (mail-lj1-x233.google.com [IPv6:2a00:1450:4864:20::233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57A20C061756; Mon, 1 Mar 2021 05:40:39 -0800 (PST) Received: by mail-lj1-x233.google.com with SMTP id a17so19438036ljq.2; Mon, 01 Mar 2021 05:40:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:subject:from:to:cc:date:in-reply-to:references :mime-version:content-transfer-encoding; bh=tfPkTHeTaVvR1yZ2FfXg8gmr0JM9q50LxKJc1Ac2dQE=; b=PecNtnGblG27Yybc7mVkavx3/j9Q0qAn4P0EovQlbGaaBLtahgShK3UmyLX5d6pb3U i4LAjuomGgAJZa/I3YCAHykgSjpt++iel9mKXb4QIq4hymK5is1/KrQ6PW292cvkztiF TjP8pjJ3H9s4+v95xIJJ1ovjeYE5eoRhKXnQvuFiTseSHeroJdzlgBbLl627YSSH3ZrU JZBpiCr5N9CEr0RqIOBSqKwU7dQ9GxmTWqEl6aAobflvu+FZNznQJgdDQeMd/rYVRbu3 ovXylYo1pXc3D5aNuFHlq8Nd517BKIIN6V34ITpwZfWiFhklhykVBepeqUYFay+HnZhp NyYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=tfPkTHeTaVvR1yZ2FfXg8gmr0JM9q50LxKJc1Ac2dQE=; b=mOMHXH8L/xdHMI0RO0RMpx63Xx+qthDtEHRGWuAUKjc2C9GVarf1aeaVZ9FpVhjFnZ xkA55aBvEmNEYsTazpcvy94HEpKbIR+iPuN3IOpjZG01fW0a7R7Apul9NvpkId6TE5jX 1uTT/dGjwD+cqOH3Df/saCCrxSmkeNHvSlqLMjiPzpqfUKUF6WXKNWwACyK1xFF5kF/u jxwE5Uz4IyKyUiHHOlE+JwEAbZy9CDGjRQYREzNYmUc+HBaxNSlJiBdNe3USoXyQfbsp yNJfb3Ihf9GRZzLkVCJ8JsEBulvtVYTT/UhA4LLpm9xeRdb1y6dKrMY9c+uo22GTb2Ra 2I6g== X-Gm-Message-State: AOAM530hLonFJ7srzLzA1wGImRwgiJeg0MiqZXH/UCNBIoN4jL1yitPW VteuqJhywoU7Tv1kgOoPhf0= X-Google-Smtp-Source: ABdhPJy9PYq6Qagabf94XBUyJH6TuCeXLiP0AfPwRl3XcnEjhFpX1XCsZsJoHj+PhU2zMM0PnldndA== X-Received: by 2002:a2e:8151:: with SMTP id t17mr8927655ljg.163.1614606037897; Mon, 01 Mar 2021 05:40:37 -0800 (PST) Received: from amakushkin-VirtualBox ([46.61.204.60]) by smtp.googlemail.com with ESMTPSA id h10sm2363229ljb.101.2021.03.01.05.40.36 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 01 Mar 2021 05:40:37 -0800 (PST) Message-ID: <4d22ecbe776ada30c8f4b553204e2776fc0d48ac.camel@gmail.com> Subject: Re: [PATCH] net/core/skbuff.c: __netdev_alloc_skb fix when len is greater than KMALLOC_MAX_SIZE From: Pavel Skripkin To: Eric Dumazet , davem@davemloft.net, kuba@kernel.org, linmiaohe@huawei.com, Sabyrzhan Tasbolatov , Alexander Lobakin Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+80dccaee7c6630fa9dcf@syzkaller.appspotmail.com Date: Mon, 01 Mar 2021 16:40:36 +0300 In-Reply-To: <24d966a7-ed2e-eb50-23e9-71ff2e43371f@gmail.com> References: <20210226191106.554553-1-paskripkin@gmail.com> <24d966a7-ed2e-eb50-23e9-71ff2e43371f@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, thanks for your reply! On Mon, 2021-03-01 at 14:09 +0100, Eric Dumazet wrote: > > On 2/26/21 8:11 PM, Pavel Skripkin wrote: > > syzbot found WARNING in __alloc_pages_nodemask()[1] when order >= > > MAX_ORDER. > > It was caused by __netdev_alloc_skb(), which doesn't check len > > value after adding NET_SKB_PAD. > > Order will be >= MAX_ORDER and passed to __alloc_pages_nodemask() > > if size > KMALLOC_MAX_SIZE. > > > > static void *kmalloc_large_node(size_t size, gfp_t flags, int node) > > { > > struct page *page; > > void *ptr = NULL; > > unsigned int order = get_order(size); > > ... > > page = alloc_pages_node(node, flags, order); > > ... > > > > [1] WARNING in __alloc_pages_nodemask+0x5f8/0x730 > > mm/page_alloc.c:5014 > > Call Trace: > > __alloc_pages include/linux/gfp.h:511 [inline] > > __alloc_pages_node include/linux/gfp.h:524 [inline] > > alloc_pages_node include/linux/gfp.h:538 [inline] > > kmalloc_large_node+0x60/0x110 mm/slub.c:3999 > > __kmalloc_node_track_caller+0x319/0x3f0 mm/slub.c:4496 > > __kmalloc_reserve net/core/skbuff.c:150 [inline] > > __alloc_skb+0x4e4/0x5a0 net/core/skbuff.c:210 > > __netdev_alloc_skb+0x70/0x400 net/core/skbuff.c:446 > > netdev_alloc_skb include/linux/skbuff.h:2832 [inline] > > qrtr_endpoint_post+0x84/0x11b0 net/qrtr/qrtr.c:442 > > qrtr_tun_write_iter+0x11f/0x1a0 net/qrtr/tun.c:98 > > call_write_iter include/linux/fs.h:1901 [inline] > > new_sync_write+0x426/0x650 fs/read_write.c:518 > > vfs_write+0x791/0xa30 fs/read_write.c:605 > > ksys_write+0x12d/0x250 fs/read_write.c:658 > > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Reported-by: syzbot+80dccaee7c6630fa9dcf@syzkaller.appspotmail.com > > Signed-off-by: Pavel Skripkin > > Change-Id: I480a6d6f818a4c0a387db0cd3f230b68a7daeb16 > > --- > > net/core/skbuff.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > > index 785daff48030..dc28c8f7bf5f 100644 > > --- a/net/core/skbuff.c > > +++ b/net/core/skbuff.c > > @@ -443,6 +443,9 @@ struct sk_buff *__netdev_alloc_skb(struct > > net_device *dev, unsigned int len, > > if (len <= SKB_WITH_OVERHEAD(1024) || > > len > SKB_WITH_OVERHEAD(PAGE_SIZE) || > > (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { > > + if (len > KMALLOC_MAX_SIZE) > > + return NULL; > > + > > skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, > > NUMA_NO_NODE); > > if (!skb) > > goto skb_fail; > > > > > No, please fix the offender instead. Yesterday I already send newer patch version to Alexander Lobakin, where I added __GFP_NOWARN in qrtr_endpoint_post(). I think, You can check it in this thread. > > Offender tentative fix was in > > commit 2a80c15812372e554474b1dba0b1d8e467af295d > Author: Sabyrzhan Tasbolatov > Date: Tue Feb 2 15:20:59 2021 +0600 > > net/qrtr: restrict user-controlled length in > qrtr_tun_write_iter() > This patch fixes kzalloc() call, but the warning was caused by __netdev_alloc_skb(). > > qrtr maintainers have to tell us what is the maximum datagram length > they need to support. > > > With regards, Pavel Skripkin