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 4D038C433FE for ; Fri, 4 Nov 2022 10:32:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231720AbiKDKcZ (ORCPT ); Fri, 4 Nov 2022 06:32:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231354AbiKDKcX (ORCPT ); Fri, 4 Nov 2022 06:32:23 -0400 Received: from mail-il1-f197.google.com (mail-il1-f197.google.com [209.85.166.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61E84240BC for ; Fri, 4 Nov 2022 03:32:22 -0700 (PDT) Received: by mail-il1-f197.google.com with SMTP id d2-20020a056e020be200b00300ecc7e0d4so1074097ilu.5 for ; Fri, 04 Nov 2022 03:32:22 -0700 (PDT) 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=bSnqp4UQlUG2QqlzZ3iUAIc6MEm8SU7cmM0LL8se2r0=; b=Gc1xfK5Bh5MwVS7vymmU1qjUrSy5WpjlDhqhRsmA6lIyeTA1uJ7+gOWGEvcc28t42+ 2Dbpm5dFBH9de7BCWdgMhF54m7nE8RSyVmDiUhMLRZ/uHtBXYAvSGWhPoITu75hgMGy4 ZWHxW+fG6mi+ldc6/Yct/Dy3jJ4sAqzCzwzHv58svcJhh1YqciRQqu4JHD6N7hMzFANp jrTVsUdinnLLqR+EuaurUT2lVyNXESdr6SNrzi9mKScnvQ1Qpki6VXA3LlMjIsfKQbN0 kegqcRkO7dVFAIt5SLNdZtYOFGfm30PYydM1rwVjaC1Mza5IkVX7UwSjQV6db4Mw8KtL 8Kjg== X-Gm-Message-State: ACrzQf04DoBc+V93AFSjzVyakvNellf+SGFk9CRJM5WIsc6UsU6SQo8/ JeBpGV3ekdHAGfYl+0sdoyQL9iUDgwBjly8z11hx0bJx4ZH7 X-Google-Smtp-Source: AMsMyM5asMkNk/IBjdzr0g1FEDiMRsuuLSd5z4zwlK77wevqztwMM0tN2ky5BWsL0Sv7NeybSiEaULNMkolgWJQqtBvmzQ0GIK5k MIME-Version: 1.0 X-Received: by 2002:a02:94ab:0:b0:35a:d1b9:c71c with SMTP id x40-20020a0294ab000000b0035ad1b9c71cmr19992511jah.310.1667557941733; Fri, 04 Nov 2022 03:32:21 -0700 (PDT) Date: Fri, 04 Nov 2022 03:32:21 -0700 In-Reply-To: <20221104103216.2576427-1-glider@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000c2709105eca2960b@google.com> Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network From: syzbot To: Alexander Potapenko Cc: davem@davemloft.net, dsahern@kernel.org, glider@google.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, yoshfuji@linux-ipv6.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > 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 > --- > net/ipv6/addrlabel.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c > index 8a22486cf2702..17ac45aa7194c 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; > -- > 2.38.1.431.g37b22c650d-goog > 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.