2022-11-04 10:40:36

by Alexander Potapenko

Subject: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

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 <[email protected]>
---
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

2022-11-04 10:45:42

by syzbot

Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

> 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 <[email protected]>
> ---
> 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 [email protected] address
but the HASH does not correspond to any known bug.
Please double check the address.

2022-11-04 11:00:02

by Alexander Potapenko

Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

>
> This patch ensures that the reserved field is always initialized.
>
> Reported-by: syzbot+3553517af6020c4f2813f1003fe76ef3cbffe98d@syzkaller.appspotmail.com

My bad, should be:
Reported-by: [email protected]

2022-11-04 11:03:01

by syzbot

Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

>>
>> This patch ensures that the reserved field is always initialized.
>>
>> Reported-by: syzbot+3553517af6020c4f2813f1003fe76ef3cbffe98d@syzkaller.appspotmail.com
>
> My bad, should be:
> Reported-by: [email protected]

I see the command but can't find the corresponding bug.
The email is sent to [email protected] address
but the HASH does not correspond to any known bug.
Please double check the address.

2022-11-04 15:16:46

by syzbot

Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

> 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 <[email protected]>
>> ---
>> net/ipv6/addrlabel.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>
> Reviewed-by: David Ahern <[email protected]>
>
>

I see the command but can't find the corresponding bug.
The email is sent to [email protected] address
but the HASH does not correspond to any known bug.
Please double check the address.

2022-11-04 16:13:52

by David Ahern

Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

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 <[email protected]>
> ---
> net/ipv6/addrlabel.c | 1 +
> 1 file changed, 1 insertion(+)
>

Reviewed-by: David Ahern <[email protected]>

2022-11-07 13:20:48

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:

On Fri, 4 Nov 2022 11:32:16 +0100 you 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
> ...
>
> [...]

Here is the summary with links:
- ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network
https://git.kernel.org/netdev/net/c/c23fb2c82267

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

2022-11-07 13:52:24

by syzbot

Subject: Re: [PATCH] ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

> Hello:
>
> This patch was applied to netdev/net.git (master)
> by David S. Miller <[email protected]>:
>
> On Fri, 4 Nov 2022 11:32:16 +0100 you 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
>> ...
>>
>> [...]
>
> Here is the summary with links:
> - ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network
> https://git.kernel.org/netdev/net/c/c23fb2c82267
>
> You are awesome, thank you!
> --
> Deet-doot-dot, I am a bot.
> https://korg.docs.kernel.org/patchwork/pwbot.html
>
>

I see the command but can't find the corresponding bug.
The email is sent to [email protected] address
but the HASH does not correspond to any known bug.
Please double check the address.