* [PATCH bpf-next] bpf: prevent non-IPv4 socket to be added into sock hash
@ 2018-05-30 21:29 Wei Wang
2018-05-31 23:31 ` John Fastabend
0 siblings, 1 reply; 5+ messages in thread
From: Wei Wang @ 2018-05-30 21:29 UTC (permalink / raw)
To: netdev, John Fastabend; +Cc: Eric Dumazet, Willem de Bruijn, Wei Wang
From: Wei Wang <weiwan@google.com>
Sock hash only supports IPv4 socket proto right now.
If a non-IPv4 socket gets stored in the BPF map, sk->sk_prot gets
overwritten with the v4 tcp prot.
Syskaller reported the following related issue on an IPv6 socket:
BUG: KASAN: slab-out-of-bounds in ip6_dst_idev include/net/ip6_fib.h:203 [inline]
BUG: KASAN: slab-out-of-bounds in ip6_xmit+0x2002/0x23f0 net/ipv6/ip6_output.c:264
Read of size 8 at addr ffff8801b300edb0 by task syz-executor888/4522
CPU: 0 PID: 4522 Comm: syz-executor888 Not tainted 4.17.0-rc4+ #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
ip6_dst_idev include/net/ip6_fib.h:203 [inline]
ip6_xmit+0x2002/0x23f0 net/ipv6/ip6_output.c:264
inet6_csk_xmit+0x377/0x630 net/ipv6/inet6_connection_sock.c:139
tcp_transmit_skb+0x1be0/0x3e40 net/ipv4/tcp_output.c:1159
tcp_send_syn_data net/ipv4/tcp_output.c:3441 [inline]
tcp_connect+0x2207/0x45a0 net/ipv4/tcp_output.c:3480
tcp_v4_connect+0x1934/0x1d50 net/ipv4/tcp_ipv4.c:272
__inet_stream_connect+0x943/0x1120 net/ipv4/af_inet.c:655
tcp_sendmsg_fastopen net/ipv4/tcp.c:1162 [inline]
tcp_sendmsg_locked+0x2859/0x3ee0 net/ipv4/tcp.c:1209
tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1447
inet_sendmsg+0x19f/0x690 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:639
___sys_sendmsg+0x805/0x940 net/socket.c:2117
__sys_sendmsg+0x115/0x270 net/socket.c:2155
__do_sys_sendmsg net/socket.c:2164 [inline]
__se_sys_sendmsg net/socket.c:2162 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43ff99
RSP: 002b:00007ffc00bd1cf8 EFLAGS: 00000217 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ff99
RDX: 0000000020000000 RSI: 0000000020000580 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000217 R12: 00000000004018c0
R13: 0000000000401950 R14: 0000000000000000 R15: 0000000000000000
Fixes: 81110384441a ("bpf: sockmap, add hash map support")
Reported-by: syzbot+5c063698bdbfac19f363@syzkaller.appspotmail.com
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
---
kernel/bpf/sockmap.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 3b28955a6383..0e7b88bc3e3f 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -2300,6 +2300,11 @@ static int sock_hash_update_elem(struct bpf_map *map,
return -EINVAL;
}
+ if (skops.sk->sk_family != AF_INET) {
+ fput(socket->file);
+ return -EAFNOSUPPORT;
+ }
+
err = sock_hash_ctx_update_elem(&skops, map, key, flags);
fput(socket->file);
return err;
--
2.17.1.1185.g55be947832-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next] bpf: prevent non-IPv4 socket to be added into sock hash
2018-05-30 21:29 [PATCH bpf-next] bpf: prevent non-IPv4 socket to be added into sock hash Wei Wang
@ 2018-05-31 23:31 ` John Fastabend
2018-06-01 1:00 ` Eric Dumazet
0 siblings, 1 reply; 5+ messages in thread
From: John Fastabend @ 2018-05-31 23:31 UTC (permalink / raw)
To: Wei Wang, netdev; +Cc: Eric Dumazet, Willem de Bruijn
On 05/30/2018 02:29 PM, Wei Wang wrote:
> From: Wei Wang <weiwan@google.com>
>
> Sock hash only supports IPv4 socket proto right now.
> If a non-IPv4 socket gets stored in the BPF map, sk->sk_prot gets
> overwritten with the v4 tcp prot.
>
> Syskaller reported the following related issue on an IPv6 socket:
> BUG: KASAN: slab-out-of-bounds in ip6_dst_idev include/net/ip6_fib.h:203 [inline]
> BUG: KASAN: slab-out-of-bounds in ip6_xmit+0x2002/0x23f0 net/ipv6/ip6_output.c:264
> Read of size 8 at addr ffff8801b300edb0 by task syz-executor888/4522
>
> CPU: 0 PID: 4522 Comm: syz-executor888 Not tainted 4.17.0-rc4+ #17
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x1b9/0x294 lib/dump_stack.c:113
> print_address_description+0x6c/0x20b mm/kasan/report.c:256
> kasan_report_error mm/kasan/report.c:354 [inline]
> kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
> __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
> ip6_dst_idev include/net/ip6_fib.h:203 [inline]
> ip6_xmit+0x2002/0x23f0 net/ipv6/ip6_output.c:264
> inet6_csk_xmit+0x377/0x630 net/ipv6/inet6_connection_sock.c:139
> tcp_transmit_skb+0x1be0/0x3e40 net/ipv4/tcp_output.c:1159
> tcp_send_syn_data net/ipv4/tcp_output.c:3441 [inline]
> tcp_connect+0x2207/0x45a0 net/ipv4/tcp_output.c:3480
> tcp_v4_connect+0x1934/0x1d50 net/ipv4/tcp_ipv4.c:272
> __inet_stream_connect+0x943/0x1120 net/ipv4/af_inet.c:655
> tcp_sendmsg_fastopen net/ipv4/tcp.c:1162 [inline]
> tcp_sendmsg_locked+0x2859/0x3ee0 net/ipv4/tcp.c:1209
> tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1447
> inet_sendmsg+0x19f/0x690 net/ipv4/af_inet.c:798
> sock_sendmsg_nosec net/socket.c:629 [inline]
> sock_sendmsg+0xd5/0x120 net/socket.c:639
> ___sys_sendmsg+0x805/0x940 net/socket.c:2117
> __sys_sendmsg+0x115/0x270 net/socket.c:2155
> __do_sys_sendmsg net/socket.c:2164 [inline]
> __se_sys_sendmsg net/socket.c:2162 [inline]
> __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162
> do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x43ff99
> RSP: 002b:00007ffc00bd1cf8 EFLAGS: 00000217 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ff99
> RDX: 0000000020000000 RSI: 0000000020000580 RDI: 0000000000000003
> RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
> R10: 00000000004002c8 R11: 0000000000000217 R12: 00000000004018c0
> R13: 0000000000401950 R14: 0000000000000000 R15: 0000000000000000
>
> Fixes: 81110384441a ("bpf: sockmap, add hash map support")
> Reported-by: syzbot+5c063698bdbfac19f363@syzkaller.appspotmail.com
> Signed-off-by: Wei Wang <weiwan@google.com>
> Acked-by: Eric Dumazet <edumazet@google.com>
> Acked-by: Willem de Bruijn <willemb@google.com>
> ---
Hi Wei,
Thanks for the report and fix. It would be better to fix the
root cause so that IPv6 works as intended.
I'm testing the following now,
Author: John Fastabend <john.fastabend@gmail.com>
Date: Thu May 31 14:38:59 2018 -0700
sockmap: fix crash when ipv6 sock is added by adding support for IPv6
Apparently we had a testing escape and missed IPv6. This fixes a crash
where we assign tcp_prot to IPv6 sockets instead of tcpv6_prot.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 52a91d8..e191122 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -41,6 +41,7 @@
#include <linux/mm.h>
#include <net/strparser.h>
#include <net/tcp.h>
+#include <net/transp_v6.h>
#include <linux/ptr_ring.h>
#include <net/inet_common.h>
#include <linux/sched/signal.h>
@@ -162,6 +163,8 @@ static bool bpf_tcp_stream_read(const struct sock *sk)
}
static struct proto tcp_bpf_proto;
+static struct proto tcpv6_bpf_proto;
+
static int bpf_tcp_init(struct sock *sk)
{
struct smap_psock *psock;
@@ -182,13 +185,21 @@ static int bpf_tcp_init(struct sock *sk)
psock->sk_proto = sk->sk_prot;
if (psock->bpf_tx_msg) {
+ tcpv6_bpf_proto.sendmsg = bpf_tcp_sendmsg;
+ tcpv6_bpf_proto.sendpage = bpf_tcp_sendpage;
+ tcpv6_bpf_proto.recvmsg = bpf_tcp_recvmsg;
+ tcpv6_bpf_proto.stream_memory_read = bpf_tcp_stream_read;
tcp_bpf_proto.sendmsg = bpf_tcp_sendmsg;
tcp_bpf_proto.sendpage = bpf_tcp_sendpage;
tcp_bpf_proto.recvmsg = bpf_tcp_recvmsg;
tcp_bpf_proto.stream_memory_read = bpf_tcp_stream_read;
}
- sk->sk_prot = &tcp_bpf_proto;
+ if (sk->sk_family == AF_INET6)
+ sk->sk_prot = &tcpv6_bpf_proto;
+ else
+ sk->sk_prot = &tcp_bpf_proto;
+
rcu_read_unlock();
return 0;
}
@@ -1113,6 +1124,8 @@ static int bpf_tcp_ulp_register(void)
{
tcp_bpf_proto = tcp_prot;
tcp_bpf_proto.close = bpf_tcp_close;
+ tcpv6_bpf_proto = tcpv6_prot;
+ tcpv6_bpf_proto.close = bpf_tcp_close;
/* Once BPF TX ULP is registered it is never unregistered. It
* will be in the ULP list for the lifetime of the system. Doing
* duplicate registers is not a problem.
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next] bpf: prevent non-IPv4 socket to be added into sock hash
2018-05-31 23:31 ` John Fastabend
@ 2018-06-01 1:00 ` Eric Dumazet
2018-06-01 7:56 ` John Fastabend
0 siblings, 1 reply; 5+ messages in thread
From: Eric Dumazet @ 2018-06-01 1:00 UTC (permalink / raw)
To: John Fastabend; +Cc: Wei Wang, netdev, Willem de Bruijn
On Thu, May 31, 2018 at 7:32 PM John Fastabend <john.fastabend@gmail.com> wrote:
>
>
> Hi Wei,
>
> Thanks for the report and fix. It would be better to fix the
> root cause so that IPv6 works as intended.
>
> I'm testing the following now,
>
> Author: John Fastabend <john.fastabend@gmail.com>
> Date: Thu May 31 14:38:59 2018 -0700
>
> sockmap: fix crash when ipv6 sock is added by adding support for IPv6
>
> Apparently we had a testing escape and missed IPv6. This fixes a crash
> where we assign tcp_prot to IPv6 sockets instead of tcpv6_prot.
>
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>
>
Hi John
In any case, please forward correct attribution for Wei's work, and
syzbot 'Reported-by'
Are you sure you are handling IPv4 mapped in IPv6 sockets as well ?
Thanks.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next] bpf: prevent non-IPv4 socket to be added into sock hash
2018-06-01 1:00 ` Eric Dumazet
@ 2018-06-01 7:56 ` John Fastabend
2018-06-01 18:40 ` John Fastabend
0 siblings, 1 reply; 5+ messages in thread
From: John Fastabend @ 2018-06-01 7:56 UTC (permalink / raw)
To: Eric Dumazet; +Cc: Wei Wang, netdev, Willem de Bruijn
On 05/31/2018 06:00 PM, Eric Dumazet wrote:
> On Thu, May 31, 2018 at 7:32 PM John Fastabend <john.fastabend@gmail.com> wrote:
>>
>>
>> Hi Wei,
>>
>> Thanks for the report and fix. It would be better to fix the
>> root cause so that IPv6 works as intended.
>>
>> I'm testing the following now,
>>
>> Author: John Fastabend <john.fastabend@gmail.com>
>> Date: Thu May 31 14:38:59 2018 -0700
>>
>> sockmap: fix crash when ipv6 sock is added by adding support for IPv6
>>
>> Apparently we had a testing escape and missed IPv6. This fixes a crash
>> where we assign tcp_prot to IPv6 sockets instead of tcpv6_prot.
>>
>> Signed-off-by: John Fastabend <john.fastabend@gmail.com>
>>
>
> Hi John
>
> In any case, please forward correct attribution for Wei's work, and
> syzbot 'Reported-by'
Will send update with tags in a moment.
>
> Are you sure you are handling IPv4 mapped in IPv6 sockets as well ?
>
No, will look into it. Although I didn't see any code to handle it
in the ./net/tls case either so if there is some issue with this it
could possibly exist in both ULPs. I guess if ipv4 mapped ipv6
changes prot or callbacks then we could stomp on it.
> Thanks.
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next] bpf: prevent non-IPv4 socket to be added into sock hash
2018-06-01 7:56 ` John Fastabend
@ 2018-06-01 18:40 ` John Fastabend
0 siblings, 0 replies; 5+ messages in thread
From: John Fastabend @ 2018-06-01 18:40 UTC (permalink / raw)
To: Eric Dumazet; +Cc: Wei Wang, netdev, Willem de Bruijn
On 06/01/2018 12:56 AM, John Fastabend wrote:
> On 05/31/2018 06:00 PM, Eric Dumazet wrote:
>> On Thu, May 31, 2018 at 7:32 PM John Fastabend <john.fastabend@gmail.com> wrote:
>>>
>>>
>>> Hi Wei,
>>>
>>> Thanks for the report and fix. It would be better to fix the
>>> root cause so that IPv6 works as intended.
>>>
>>> I'm testing the following now,
>>>
>>> Author: John Fastabend <john.fastabend@gmail.com>
>>> Date: Thu May 31 14:38:59 2018 -0700
>>>
>>> sockmap: fix crash when ipv6 sock is added by adding support for IPv6
>>>
>>> Apparently we had a testing escape and missed IPv6. This fixes a crash
>>> where we assign tcp_prot to IPv6 sockets instead of tcpv6_prot.
>>>
>>> Signed-off-by: John Fastabend <john.fastabend@gmail.com>
>>>
>>
>> Hi John
>>
>> In any case, please forward correct attribution for Wei's work, and
>> syzbot 'Reported-by'
>
> Will send update with tags in a moment.
>
>>
>> Are you sure you are handling IPv4 mapped in IPv6 sockets as well ?
>>
>
> No, will look into it. Although I didn't see any code to handle it
> in the ./net/tls case either so if there is some issue with this it
> could possibly exist in both ULPs. I guess if ipv4 mapped ipv6
> changes prot or callbacks then we could stomp on it.
>
Will need a v2 to address this, by adding a check to only work on
ESTABLISHED sockets we resolve this issue and the one noted in the
TLS ULP side as well.
Thanks a lot Eric.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2018-05-30 21:29 [PATCH bpf-next] bpf: prevent non-IPv4 socket to be added into sock hash Wei Wang
2018-05-31 23:31 ` John Fastabend
2018-06-01 1:00 ` Eric Dumazet
2018-06-01 7:56 ` John Fastabend
2018-06-01 18:40 ` John Fastabend
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