From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f199.google.com (mail-il1-f199.google.com [209.85.166.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96EF37B for ; Wed, 23 Nov 2022 08:58:46 +0000 (UTC) Received: by mail-il1-f199.google.com with SMTP id o10-20020a056e02102a00b003006328df7bso12611599ilj.17 for ; Wed, 23 Nov 2022 00:58:46 -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=VnVueKTZoShuUXW7zwHhg0Gb9tesJnQcU/uJSiALPAA=; b=fDkaAKddhnPKfJ/NkXsRjzzAgp0FKJrywwT22qLrLyCtWAnUbpdcqxNgOVPPLDXdfh GChdNA102d6sYkWxjZqiVfaGXvsAVhfmytpRVgMdS6fi4cTrlV7lYhSUMbtOu/SuOlFT wdeA0S2XZt7MdJkU4PkPWXG0xmv8xl7lT9rO1+WYPO2koQ+WJUYVJpjBtb8ZlLabQMQw wHByjiPN2eJCMYJsVqLqilKr85HLWT144BtmttMxQfqs5EAYh7vZRb0IqYTxt7OblbDF Alh9gTqWxeeXZJhDLxPKeQdYmlOH7uxmvth8QaUI7yxJJn3nqUhPo40mYAlKxSl7NXTq l7RA== X-Gm-Message-State: ANoB5pnSqK/VS+lMYjRriO5Eds90wgBO+cjNRLkKCDTVEV0W9jIjm9Cy PJE9S8ctW3dypsyke2PFReOmLH7MV+F86ohA9nCVjHQUJh3O X-Google-Smtp-Source: AA0mqf6evUrN5h5EVPATBIZ0obUu4buZG/KATYMorRQ7hixUH3ww3U47LrFDRtmmNGg1D3cnlvQdpEn3YOGqPMf2wnzItsPExDEB Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a92:874e:0:b0:2f9:32c2:a10a with SMTP id d14-20020a92874e000000b002f932c2a10amr3863147ilm.47.1669193925813; Wed, 23 Nov 2022 00:58:45 -0800 (PST) Date: Wed, 23 Nov 2022 00:58:45 -0800 In-Reply-To: <20221123084548.847749891@linuxfoundation.org> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000026c4005ee1f7fcc@google.com> Subject: Re: [PATCH 4.14 09/88] 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" > 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 f664871feca6..4e215cfb5fa9 100644 > --- a/net/ipv6/addrlabel.c > +++ b/net/ipv6/addrlabel.c > @@ -474,6 +474,7 @@ 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.