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 E59AB1C26 for ; Wed, 23 Nov 2022 09:05:04 +0000 (UTC) Received: by mail-il1-f199.google.com with SMTP id x10-20020a056e021bca00b00302b6c0a683so8437145ilv.23 for ; Wed, 23 Nov 2022 01:05:04 -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=hOwaUP9SnaHg7GvHDtdq80VwQovF/jP7FuJHxUUIH1w=; b=CdTmGXh7Me1QL4aXw5m1zcnYi+lN6XeC9Ezu4YrS83zcXRa4nys2M6jGit211ZD4ND Z0VFrvHxVXW9Ogs2vZpJtTLxHlYKXD+X75zajtLWqw9Ha9edL13m/UMNDW/e/DaDVviR o5A+Poyh6liTCJrSVfeyuqlpj+lYTBXBmN5TingOPyWQLoMbG2aayAYwf7Q4Ws+cz/p/ QFx+snGd/xyxQjGPbBM/jiWiHGWLIRsYWJoLq9lb/QxfKbzHIo1l0wGP72SX0D1KAGAT cwtmoeM3KBbXogCHPhxAAdYYYGu6QgGiSaBcwbnWbBhgmztItbZOvJPZ8P3lHw1GIOmP Taqg== X-Gm-Message-State: ANoB5pkYfuXskIDd+aVbZHlEGBtePES8xf5RNmy6qvdVVB9CFVPGDYiw BX4E5MJtL7LvEoSGnZLdfdDy+ozfRg+V/noj3QPjYCChqlMW X-Google-Smtp-Source: AA0mqf7SdlyZACq4cXIrmJqHAqNcAdRgWSbuK5H6M+yoJ1JAc2cVG1j8G8YLFXsab5Beg4+24GIvpt0zW9qBCvmAblAA6gaEz4CG Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a5e:aa06:0:b0:6bc:614c:63c2 with SMTP id s6-20020a5eaa06000000b006bc614c63c2mr5330231ioe.21.1669194304118; Wed, 23 Nov 2022 01:05:04 -0800 (PST) Date: Wed, 23 Nov 2022 01:05:04 -0800 In-Reply-To: <20221123084552.337303067@linuxfoundation.org> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000008ee66405ee1f9570@google.com> Subject: Re: [PATCH 4.19 012/114] 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 c7dc8b2de6c2..7fdd433b968e 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.