Commit Graph

9 Commits

Author SHA1 Message Date
Liu Jian d900f3d20c bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser()
When the buffer length of the recvmsg system call is 0, we got the
flollowing soft lockup problem:

watchdog: BUG: soft lockup - CPU#3 stuck for 27s! [a.out:6149]
CPU: 3 PID: 6149 Comm: a.out Kdump: loaded Not tainted 6.2.0+ #30
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:remove_wait_queue+0xb/0xc0
Code: 5e 41 5f c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 57 <41> 56 41 55 41 54 55 48 89 fd 53 48 89 f3 4c 8d 6b 18 4c 8d 73 20
RSP: 0018:ffff88811b5978b8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88811a7d3780 RCX: ffffffffb7a4d768
RDX: dffffc0000000000 RSI: ffff88811b597908 RDI: ffff888115408040
RBP: 1ffff110236b2f1b R08: 0000000000000000 R09: ffff88811a7d37e7
R10: ffffed10234fa6fc R11: 0000000000000001 R12: ffff88811179b800
R13: 0000000000000001 R14: ffff88811a7d38a8 R15: ffff88811a7d37e0
FS:  00007f6fb5398740(0000) GS:ffff888237180000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 000000010b6ba002 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tcp_msg_wait_data+0x279/0x2f0
 tcp_bpf_recvmsg_parser+0x3c6/0x490
 inet_recvmsg+0x280/0x290
 sock_recvmsg+0xfc/0x120
 ____sys_recvmsg+0x160/0x3d0
 ___sys_recvmsg+0xf0/0x180
 __sys_recvmsg+0xea/0x1a0
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

The logic in tcp_bpf_recvmsg_parser is as follows:

msg_bytes_ready:
	copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
	if (!copied) {
		wait data;
		goto msg_bytes_ready;
	}

In this case, "copied" always is 0, the infinite loop occurs.

According to the Linux system call man page, 0 should be returned in this
case. Therefore, in tcp_bpf_recvmsg_parser(), if the length is 0, directly
return. Also modify several other functions with the same problem.

Fixes: 1f5be6b3b0 ("udp: Implement udp_bpf_recvmsg() for sockmap")
Fixes: 9825d866ce ("af_unix: Implement unix_dgram_bpf_recvmsg()")
Fixes: c5d2177a72 ("bpf, sockmap: Fix race in ingress receive verdict with redirect to self")
Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230303080946.1146638-1-liujian56@huawei.com
2023-03-03 17:25:15 +01:00
Pavel Begunkov fee9ac0664 net: remove SOCK_SUPPORT_ZC from sockmap
sockmap replaces ->sk_prot with its own callbacks, we should remove
SOCK_SUPPORT_ZC as the new proto doesn't support msghdr::ubuf_info.

Cc: <stable@vger.kernel.org> # 6.0
Reported-by: Jakub Kicinski <kuba@kernel.org>
Fixes: e993ffe3da ("net: flag sockets supporting msghdr originated zerocopy")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-28 20:21:25 -07:00
Oliver Hartkopp ec095263a9 net: remove noblock parameter from recvmsg() entities
The internal recvmsg() functions have two parameters 'flags' and 'noblock'
that were merged inside skb_recv_datagram(). As a follow up patch to commit
f4b41f062c ("net: remove noblock parameter from skb_recv_datagram()")
this patch removes the separate 'noblock' parameter for recvmsg().

Analogue to the referenced patch for skb_recv_datagram() the 'flags' and
'noblock' parameters are unnecessarily split up with e.g.

err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
                           flags & ~MSG_DONTWAIT, &addr_len);

or in

err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
                      sk, msg, size, flags & MSG_DONTWAIT,
                      flags & ~MSG_DONTWAIT, &addr_len);

instead of simply using only flags all the time and check for MSG_DONTWAIT
where needed (to preserve for the formerly separated no(n)block condition).

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20220411124955.154876-1-socketcan@hartkopp.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-04-12 15:00:25 +02:00
Cong Wang af49338895 net: Implement ->sock_is_readable() for UDP and AF_UNIX
Yucong noticed we can't poll() sockets in sockmap even
when they are the destination sockets of redirections.
This is because we never poll any psock queues in ->poll(),
except for TCP. With ->sock_is_readable() now we can
overwrite >sock_is_readable(), invoke and implement it for
both UDP and AF_UNIX sockets.

Reported-by: Yucong Sun <sunyucong@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211008203306.37525-4-xiyou.wangcong@gmail.com
2021-10-26 12:29:33 -07:00
Jiang Wang 94531cfcbe af_unix: Add unix_stream_proto for sockmap
Previously, sockmap for AF_UNIX protocol only supports
dgram type. This patch add unix stream type support, which
is similar to unix_dgram_proto. To support sockmap, dgram
and stream cannot share the same unix_proto anymore, because
they have different implementations, such as unhash for stream
type (which will remove closed or disconnected sockets from the map),
so rename unix_proto to unix_dgram_proto and add a new
unix_stream_proto.

Also implement stream related sockmap functions.
And add dgram key words to those dgram specific functions.

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-3-jiang.wang@bytedance.com
2021-08-16 18:43:39 -07:00
Cong Wang 83f3153556 bpf, unix: Check socket type in unix_bpf_update_proto()
As of now, only AF_UNIX datagram socket supports sockmap. But
unix_proto is shared for all kinds of AF_UNIX sockets, so we
have to check the socket type in unix_bpf_update_proto() to
explicitly reject other types, otherwise they could be added
into sockmap, too.

Fixes: c63829182c ("af_unix: Implement ->psock_update_sk_prot()")
Reported-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210731195038.8084-1-xiyou.wangcong@gmail.com
2021-08-03 12:52:53 +02:00
Cong Wang 0b84644598 unix_bpf: Fix a potential deadlock in unix_dgram_bpf_recvmsg()
As Eric noticed, __unix_dgram_recvmsg() may acquire u->iolock
too, so we have to release it before calling this function.

Fixes: 9825d866ce ("af_unix: Implement unix_dgram_bpf_recvmsg()")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
2021-07-30 12:40:55 -07:00
Cong Wang 9825d866ce af_unix: Implement unix_dgram_bpf_recvmsg()
We have to implement unix_dgram_bpf_recvmsg() to replace the
original ->recvmsg() to retrieve skmsg from ingress_msg.

AF_UNIX is again special here because the lack of
sk_prot->recvmsg(). I simply add a special case inside
unix_dgram_recvmsg() to call sk->sk_prot->recvmsg() directly.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210704190252.11866-8-xiyou.wangcong@gmail.com
2021-07-15 18:17:50 -07:00
Cong Wang c63829182c af_unix: Implement ->psock_update_sk_prot()
Now we can implement unix_bpf_update_proto() to update
sk_prot, especially prot->close().

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210704190252.11866-7-xiyou.wangcong@gmail.com
2021-07-15 18:17:50 -07:00