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=-15.7 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_GIT 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 C1CAEC433E0 for ; Sat, 27 Feb 2021 17:59:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F03264E46 for ; Sat, 27 Feb 2021 17:59:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230334AbhB0R6N (ORCPT ); Sat, 27 Feb 2021 12:58:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230203AbhB0RwI (ORCPT ); Sat, 27 Feb 2021 12:52:08 -0500 Received: from mail-lf1-x132.google.com (mail-lf1-x132.google.com [IPv6:2a00:1450:4864:20::132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1970C061786; Sat, 27 Feb 2021 09:51:26 -0800 (PST) Received: by mail-lf1-x132.google.com with SMTP id m22so18831947lfg.5; Sat, 27 Feb 2021 09:51:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Ob2T5k5brIJdqBYE3JocrXjjMAfzSoc4Yi9iZ4BS4g0=; b=nljZq5CZm9iha7F+TswMiWD+hvhRHZnQYr8qKmzybXWkNyEEcF8GzWeTrQ30PoIiL0 J6lCfl8asKJ1HA4AzjU13ufz7jj0XZP38lnav3h/wyBCBdftr7Rpy2ujv/81oGtww54F KeM7boqNAe9H/L4uFsKvkz4X6D9AWj15ARaI6FG8+KOciYJEC1Tq9jakyvQARh9XO/y8 AmT3daoTVpg6KvnorlkKvGzZKzucrHZVVG9Q3lhR2uwlGInh+jN/1Z5wcBc43UTBj+MG OU6oUmtDJiwSbyw/97/V9WTDm/pWaYKRdaHIGenlXTLlQmBvoVWwrntowNztpOu6djq7 nHUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Ob2T5k5brIJdqBYE3JocrXjjMAfzSoc4Yi9iZ4BS4g0=; b=hHlEcaNmvBnKZ/kub9sRUA/k5HqqV6Zsa2OukB+/hqziskNNQERW0jA2em0drYo41N kdogV1B0XQJukuOcQmjEa/SHC8eD04duzDgrkDMZdpcVPpKspaBIwPEtj4fx5maMXWeH 1i9bpnHiCdQ1jyMaZL/hxKRMpQ8QHovCug9Yc5bIv1qO9vx8BezWb1q6Yy8QVw0R18dy ImPR8SXsFr2II1FS/1r4/wBRwh80FN9sZO8pJg5N0UA2XpVj+i4bpO7TJkBgjZq8agFs 3CK1YsJAPER5zAYbHVlafxE57Go4Dx08cJ2MykcEk0yVpydL6C3NSW/m7HegnQryuqPl dlPA== X-Gm-Message-State: AOAM530y2U7hE8Sb4eW+edJf5Tymd0xJfS3lL+j8zt17rYK8FmB0ioB9 TXU6KEPdPa/yy05Nbe2P4Nk= X-Google-Smtp-Source: ABdhPJyj1b5SuvwrUqVrc2WxYEd/+2Y6h5HzYiycTLhmbuDXDQY89gnMjIphPbsj/3pXEEaRkxZbKw== X-Received: by 2002:a05:6512:3184:: with SMTP id i4mr5109972lfe.314.1614448285223; Sat, 27 Feb 2021 09:51:25 -0800 (PST) Received: from localhost.localdomain ([94.103.235.59]) by smtp.gmail.com with ESMTPSA id x192sm522455lff.68.2021.02.27.09.51.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 27 Feb 2021 09:51:24 -0800 (PST) From: Pavel Skripkin To: alobakin@pm.me Cc: davem@davemloft.net, linmiaohe@huawei.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pavel Skripkin , syzbot+80dccaee7c6630fa9dcf@syzkaller.appspotmail.com Subject: [PATCH v3] net/core/skbuff: fix passing wrong size to __alloc_skb Date: Sat, 27 Feb 2021 20:51:14 +0300 Message-Id: <20210227175114.28645-1-paskripkin@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210227110306.13360-1-alobakin@pm.me> References: <20210227110306.13360-1-alobakin@pm.me> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Same happens in __napi_alloc_skb. 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 --- Changes from v3: * Removed Change-Id and extra tabs in net/core/skbuff.c Changes from v2: * Added length check to __napi_alloc_skb * Added unlikely() in checks Change from v1: * Added length check to __netdev_alloc_skb --- net/core/skbuff.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 785daff48030..ec7ba8728b61 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 (unlikely(len > KMALLOC_MAX_SIZE)) + return NULL; + skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE); if (!skb) goto skb_fail; @@ -517,6 +520,9 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, if (len <= SKB_WITH_OVERHEAD(1024) || len > SKB_WITH_OVERHEAD(PAGE_SIZE) || (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { + if (unlikely(len > KMALLOC_MAX_SIZE)) + return NULL; + skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE); if (!skb) goto skb_fail; -- 2.25.1