From: David Ahern <dsahern@kernel.org>
To: Alexander Potapenko <glider@google.com>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
davem@davemloft.net, yoshfuji@linux-ipv6.org,
syzbot+3553517af6020c4f2813f1003fe76ef3cbffe98d@syzkaller.appspotmail.com
Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network
Date: Fri, 4 Nov 2022 08:50:13 -0600 [thread overview]
Message-ID: <73f88a48-72e8-e6e7-faae-1d4b92e0e13b@kernel.org> (raw)
In-Reply-To: <20221104103216.2576427-1-glider@google.com>
On 11/4/22 4:32 AM, Alexander Potapenko wrote:
> 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 <glider@google.com>
> ---
> net/ipv6/addrlabel.c | 1 +
> 1 file changed, 1 insertion(+)
>
Reviewed-by: David Ahern <dsahern@kernel.org>
next prev parent reply other threads:[~2022-11-04 14:50 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-04 10:32 [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network Alexander Potapenko
2022-11-04 10:32 ` syzbot
2022-11-04 10:37 ` Alexander Potapenko
2022-11-04 10:38 ` syzbot
2022-11-04 14:50 ` David Ahern [this message]
2022-11-04 14:50 ` syzbot
2022-11-07 12:30 ` patchwork-bot+netdevbpf
2022-11-07 12:30 ` syzbot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=73f88a48-72e8-e6e7-faae-1d4b92e0e13b@kernel.org \
--to=dsahern@kernel.org \
--cc=davem@davemloft.net \
--cc=glider@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=syzbot+3553517af6020c4f2813f1003fe76ef3cbffe98d@syzkaller.appspotmail.com \
--cc=yoshfuji@linux-ipv6.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.