From patchwork Wed Dec 23 16:52:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Taehee Yoo X-Patchwork-Id: 351778 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=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 4F70BC433DB for ; Wed, 23 Dec 2020 16:53:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A2D62229C for ; Wed, 23 Dec 2020 16:53:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726462AbgLWQxl (ORCPT ); Wed, 23 Dec 2020 11:53:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725833AbgLWQxk (ORCPT ); Wed, 23 Dec 2020 11:53:40 -0500 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DD71C06179C for ; Wed, 23 Dec 2020 08:53:00 -0800 (PST) Received: by mail-pf1-x432.google.com with SMTP id h186so10704713pfe.0 for ; Wed, 23 Dec 2020 08:53:00 -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; bh=orFQMFz+YCqCTP0/OfqfsKyHfSekW5/NBNaaI2OEEZ8=; b=Nn6eBHMYnjLo0AK21LtPlA06yq5zG5eFLKxtTE0KyEXPvobpNC88P8M8/uIYwePc/Z hDlupqhm64aLXP6s4krBI/5DJT4JGpQ5P8UdQZdv+SQ7c0EHYU5STaY+zrjZp9IhhINN eFoyGtJtJZ/E13CwmusKGzmsM4GgbNJDTAaR7gPvrhXrjpxb+jShhU0nVWZUWD5sCIva 0XE7q/ErS75qdS1YfhGv2Ox70Xh7BPWvkA6J6eUeUvM76VymFC3g31yM2lu+ImfNtKq0 UAtuwd1+mJydvBGB1cv/HHrqUfBWJVQLX+2/Z1COOxafmkR4qJpuPW/aPFZhGsHyYFwq k9gA== 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; bh=orFQMFz+YCqCTP0/OfqfsKyHfSekW5/NBNaaI2OEEZ8=; b=M+v3yQf3wQgeZ+u6Xt9EVSfXxu7kqyFPADs33SqBqrAgoqnlhQrHWkHqPmhYT3yti+ 67dEN9zgShD+ae8QZohAqKqZ5BwVMYM97QqwxLYa+F1jhsLEHvJ7HyrmP5eTUmQVaayR gtDTOIvo4w+0NAS2zXTLnTHNlI+pd/aEqIp0Pbgvi+Kwxqg0kz0b3/OhddDCjlbS0ZG/ YoUNuUDbeBhkr5MwRAE+Nu4Xs9E4wDy0GytQi5QnD6UWDgBZjnO95O/4fCQZykP8/IDi SRUgtQWfP8K1GLJkf5Q8tUqQQbelJ2YeE1UDQIgJVe8vb2+OjEAFuzBjrpgaAczb0iKD YPWA== X-Gm-Message-State: AOAM53370zbUMQh2nKzxFArtq3C8a4uVj4bUiLa62yJ1TdfuwPI1cyXH 0NYywLhrMlKr8hYgP99GFdo= X-Google-Smtp-Source: ABdhPJzpmc69JMvcNyvJqyJKBWWqs1ymCgI0Byfy0CM4Ha05vZQ0rzGgQAmrEfBIl8t6qllig4inYQ== X-Received: by 2002:a62:3002:0:b029:1aa:d858:cdd7 with SMTP id w2-20020a6230020000b02901aad858cdd7mr25149855pfw.1.1608742380137; Wed, 23 Dec 2020 08:53:00 -0800 (PST) Received: from localhost.localdomain ([49.173.165.50]) by smtp.gmail.com with ESMTPSA id e5sm24164057pfc.76.2020.12.23.08.52.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Dec 2020 08:52:59 -0800 (PST) From: Taehee Yoo To: davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org Cc: ap420073@gmail.com, eric.dumazet@gmail.com Subject: [PATCH net] mld: fix panic in mld_newpack() Date: Wed, 23 Dec 2020 16:52:50 +0000 Message-Id: <20201223165250.14505-1-ap420073@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org mld_newpack() doesn't allow to allocate high order page, just order-0 allocation is allowed. If headroom size is too large, a kernel panic could occur in skb_put(). Test commands: ip netns add A ip netns add B ip link add veth0 type veth peer name veth1 ip link set veth0 netns A ip link set veth1 netns B ip netns exec A ip link set lo up ip netns exec A ip link set veth0 up ip netns exec A ip link add ip6tnl100 type ip6tnl local 2001:db8:99::1 \ remote 2001:db8:99::2 ip netns exec A ip -6 a a 2001:db8:100::1/64 dev ip6tnl100 ip netns exec A ip link set ip6tnl100 up for i in {99..1} do let A=$i-1 ip netns exec A ip link add ip6tnl$i type ip6tnl local \ 2001:db8:$A::1 remote 2001:db8:$A::2 ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev ip6tnl$i ip netns exec A ip link set ip6tnl$i up done ip netns exec A ip -6 a a 2001:db8:0::1/64 dev veth0 ip netns exec B ip link set lo up ip netns exec B ip link set veth1 up ip netns exec B ip link add ip6tnl100 type ip6tnl local 2001:db8:99::2 \ remote 2001:db8:99::1 ip netns exec B ip -6 a a 2001:db8:100::2/64 dev ip6tnl100 ip netns exec B ip link set ip6tnl100 up for i in {99..1} do let B=$i-1 ip netns exec B ip link add ip6tnl$i type ip6tnl local \ 2001:db8:$B::2 remote 2001:db8:$B::1 ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev ip6tnl$i ip netns exec B ip link set ip6tnl$i up done ip netns exec B ip -6 a a 2001:db8:0::2/64 dev veth1 Splat looks like: [ 104.047694][ T104] skbuff: skb_over_panic: text:ffffffffb0c31a92 len:56 put:8 head:ffff888009609000 data:ffff888009609e90 tail:0xec8 end:0xec0 dev:ip6gre4b [ 104.053431][ T104] ------------[ cut here ]------------ [ 104.055733][ T104] kernel BUG at net/core/skbuff.c:109! [ 104.058014][ T104] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 104.060761][ T104] CPU: 4 PID: 104 Comm: kworker/4:1 Not tainted 5.10.0+ #811 [ 104.064000][ T104] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 104.068077][ T104] Workqueue: ipv6_addrconf addrconf_dad_work [ 104.070096][ T104] RIP: 0010:skb_panic+0x15d/0x15f [ 104.072335][ T104] Code: 98 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 60 8b 78 b1 41 57 41 56 41 55 48 8b 54 24 20 48 8b 74 24 28 e8 b5 40 f9 ff <0f> 0b 48 8b 6c 24 20 89 34 24 e8 08 c9 98 fe 8b 34 24 48 c7 c1 80 [ 104.079948][ T104] RSP: 0018:ffff888102557870 EFLAGS: 00010282 [ 104.082361][ T104] RAX: 0000000000000088 RBX: ffff888101c7c000 RCX: 0000000000000000 [ 104.085878][ T104] RDX: 0000000000000088 RSI: 0000000000000008 RDI: ffffed10204aaf05 [ 104.088906][ T104] RBP: ffff8881165f60c0 R08: ffffed102338018d R09: ffffed102338018d [ 104.092111][ T104] R10: ffff888119c00c67 R11: ffffed102338018c R12: 0000000000000008 [ 104.095291][ T104] R13: ffff888009609e90 R14: 0000000000000ec8 R15: 0000000000000ec0 [ 104.098023][ T104] FS: 0000000000000000(0000) GS:ffff888119a00000(0000) knlGS:0000000000000000 [ 104.101532][ T104] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 104.103972][ T104] CR2: 000055a06421b7cc CR3: 000000010d55a002 CR4: 00000000003706e0 [ 104.107058][ T104] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 104.110048][ T104] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 104.113020][ T104] Call Trace: [ 104.114253][ T104] ? mld_newpack+0x4d2/0x8f0 [ 104.115875][ T104] ? mld_newpack+0x4d2/0x8f0 [ 104.117389][ T104] skb_put.cold.104+0x22/0x22 [ 104.118940][ T104] mld_newpack+0x4d2/0x8f0 [ 104.120389][ T104] ? ip6_mc_hdr.isra.25.constprop.47+0x600/0x600 [ 104.122466][ T104] ? register_lock_class+0x1910/0x1910 [ 104.124256][ T104] ? mark_lock.part.46+0xef/0x1c20 [ 104.125925][ T104] add_grhead.isra.32+0x280/0x380 [ 104.127574][ T104] add_grec+0xb13/0xdc0 [ 104.128952][ T104] ? rcu_read_lock_bh_held+0xa0/0xa0 [ ... ] Allowing high order page allocation could fix this problem. Fixes: 72e09ad107e7 ("ipv6: avoid high order allocations") Signed-off-by: Taehee Yoo --- net/ipv6/mcast.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index 6c8604390266..2cab0c563214 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -1601,10 +1601,7 @@ static struct sk_buff *mld_newpack(struct inet6_dev *idev, unsigned int mtu) IPV6_TLV_PADN, 0 }; /* we assume size > sizeof(ra) here */ - /* limit our allocations to order-0 page */ - size = min_t(int, size, SKB_MAX_ORDER(0, 0)); skb = sock_alloc_send_skb(sk, size, 1, &err); - if (!skb) return NULL;