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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61596C4332F for ; Wed, 23 Nov 2022 09:11:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237228AbiKWJLQ (ORCPT ); Wed, 23 Nov 2022 04:11:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237252AbiKWJKy (ORCPT ); Wed, 23 Nov 2022 04:10:54 -0500 Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1D00105A9B for ; Wed, 23 Nov 2022 01:10:48 -0800 (PST) Received: by mail-il1-f198.google.com with SMTP id d2-20020a056e020be200b00300ecc7e0d4so12528193ilu.5 for ; Wed, 23 Nov 2022 01:10:48 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=JKRy0CJM2YQG2Hu2gnfO6l4tPm0XXvuBZUpkz/Gz8Fc=; b=lg9e0Ms3SmixDM5Cg9heWQ8UEQvIn4D61gROHrOnA7do8pPGt0ytjqojc+8PpnfyE8 Hv3coqeSAbgZspfG08uuEfAvaitn0oGNi7U1XSf19DLod7MsAXCFHXzjiYevdJGbtd+I Kr/rzjrFD0RZ//nLRdamDUQGQsVbk8nSLIvZFW+GddvMu4x7hL4+Hye9SuRB3vGokqeV DisojAyH1AnsyAVEV2+j7qxOtSpEsLCyia6A6RJ4yW1R52SYoFlYsn0gLLKBcntwpZwJ y2Pd+ElcC7VAQoyQnv4hdoD6aP91TxGUrWtApI9Od2+8eoU2Vx/twQ+zruLzHn7iYrtl nA/A== X-Gm-Message-State: ANoB5pmDGlMjf8PRnOQ3I2Imm5wHPsuPw9/6x0+zC9vCGmylbERlDZ5V dLY/yB9WXXWjMaqKAhhcaAkV2O5r8UK0D/u0BBT4R3ujExlM X-Google-Smtp-Source: AA0mqf40CnljasP7XyrK6T0jA+h60K+n/TPxI7zyfqTFe4dT+717LMK8iMmeRlfO+w05jW+8Sl8M1t9aF1N5jHQvb6/FV/RPVRPB MIME-Version: 1.0 X-Received: by 2002:a92:c506:0:b0:302:4981:64b with SMTP id r6-20020a92c506000000b003024981064bmr3432850ilg.200.1669194648289; Wed, 23 Nov 2022 01:10:48 -0800 (PST) Date: Wed, 23 Nov 2022 01:10:48 -0800 In-Reply-To: <20221123084558.693459104@linuxfoundation.org> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000012891b05ee1faa57@google.com> Subject: Re: [PATCH 5.4 021/156] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network From: syzbot To: gregkh@linuxfoundation.org Cc: davem@davemloft.net, dsahern@kernel.org, glider@google.com, gregkh@linuxfoundation.org, patches@lists.linux.dev, sashal@kernel.org, stable@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org > From: Alexander Potapenko > > [ Upstream commit c23fb2c82267638f9d206cb96bb93e1f93ad7828 ] > > When copying a `struct ifaddrlblmsg` to the network, __ifal_reserved > remained uninitialized, resulting in a 1-byte infoleak: > > BUG: KMSAN: kernel-network-infoleak in __netdev_start_xmit ./include/linux/netdevice.h:4841 > __netdev_start_xmit ./include/linux/netdevice.h:4841 > netdev_start_xmit ./include/linux/netdevice.h:4857 > xmit_one net/core/dev.c:3590 > dev_hard_start_xmit+0x1dc/0x800 net/core/dev.c:3606 > __dev_queue_xmit+0x17e8/0x4350 net/core/dev.c:4256 > dev_queue_xmit ./include/linux/netdevice.h:3009 > __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 > __netlink_deliver_tap+0x728/0xad0 net/netlink/af_netlink.c:325 > netlink_deliver_tap net/netlink/af_netlink.c:338 > __netlink_sendskb net/netlink/af_netlink.c:1263 > netlink_sendskb+0x1d9/0x200 net/netlink/af_netlink.c:1272 > netlink_unicast+0x56d/0xf50 net/netlink/af_netlink.c:1360 > nlmsg_unicast ./include/net/netlink.h:1061 > rtnl_unicast+0x5a/0x80 net/core/rtnetlink.c:758 > ip6addrlbl_get+0xfad/0x10f0 net/ipv6/addrlabel.c:628 > rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082 > ... > Uninit was created at: > slab_post_alloc_hook+0x118/0xb00 mm/slab.h:742 > slab_alloc_node mm/slub.c:3398 > __kmem_cache_alloc_node+0x4f2/0x930 mm/slub.c:3437 > __do_kmalloc_node mm/slab_common.c:954 > __kmalloc_node_track_caller+0x117/0x3d0 mm/slab_common.c:975 > kmalloc_reserve net/core/skbuff.c:437 > __alloc_skb+0x27a/0xab0 net/core/skbuff.c:509 > alloc_skb ./include/linux/skbuff.h:1267 > nlmsg_new ./include/net/netlink.h:964 > ip6addrlbl_get+0x490/0x10f0 net/ipv6/addrlabel.c:608 > rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082 > netlink_rcv_skb+0x299/0x550 net/netlink/af_netlink.c:2540 > rtnetlink_rcv+0x26/0x30 net/core/rtnetlink.c:6109 > netlink_unicast_kernel net/netlink/af_netlink.c:1319 > netlink_unicast+0x9ab/0xf50 net/netlink/af_netlink.c:1345 > netlink_sendmsg+0xebc/0x10f0 net/netlink/af_netlink.c:1921 > ... > > This patch ensures that the reserved field is always initialized. > > Reported-by: syzbot+3553517af6020c4f2813f1003fe76ef3cbffe98d@syzkaller.appspotmail.com > Fixes: 2a8cc6c89039 ("[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.") > Signed-off-by: Alexander Potapenko > Reviewed-by: David Ahern > Signed-off-by: David S. Miller > Signed-off-by: Sasha Levin > --- > net/ipv6/addrlabel.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c > index 8a22486cf270..17ac45aa7194 100644 > --- a/net/ipv6/addrlabel.c > +++ b/net/ipv6/addrlabel.c > @@ -437,6 +437,7 @@ static void ip6addrlbl_putmsg(struct nlmsghdr *nlh, > { > struct ifaddrlblmsg *ifal = nlmsg_data(nlh); > ifal->ifal_family = AF_INET6; > + ifal->__ifal_reserved = 0; > ifal->ifal_prefixlen = prefixlen; > ifal->ifal_flags = 0; > ifal->ifal_index = ifindex; > -- > 2.35.1 > > > I see the command but can't find the corresponding bug. The email is sent to syzbot+HASH@syzkaller.appspotmail.com address but the HASH does not correspond to any known bug. Please double check the address.