6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michal Luczaj <mhal@xxxxxxx>
[ Upstream commit 8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f ]
sockmap expects all vsocks to have a transport assigned, which is expressed
in vsock_proto::psock_update_sk_prot(). However, there is an edge case
where an unconnected (connectible) socket may lose its previously assigned
transport. This is handled with a NULL check in the vsock/BPF recv path.
Another design detail is that listening vsocks are not supposed to have any
transport assigned at all. Which implies they are not supported by the
sockmap. But this is complicated by the fact that a socket, before
switching to TCP_LISTEN, may have had some transport assigned during a
failed connect() attempt. Hence, we may end up with a listening vsock in a
sockmap, which blows up quickly:
KASAN: null-ptr-deref in range [0x0000000000000120-0x0000000000000127]
CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 Not tainted 6.14.0-rc1+
Workqueue: vsock-loopback vsock_loopback_work
RIP: 0010:vsock_read_skb+0x4b/0x90
Call Trace:
sk_psock_verdict_data_ready+0xa4/0x2e0
virtio_transport_recv_pkt+0x1ca8/0x2acc
vsock_loopback_work+0x27d/0x3f0
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x35a/0x700
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
For connectible sockets, instead of relying solely on the state of
vsk->transport, tell sockmap to only allow those representing established
connections. This aligns with the behaviour for AF_INET and AF_UNIX.
Fixes: 634f1a7110b4 ("vsock: support sockmap")
Signed-off-by: Michal Luczaj <mhal@xxxxxxx>
Acked-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/core/sock_map.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index f37a26efdd8ab..dcc0f31a17a8d 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -538,6 +538,9 @@ static bool sock_map_sk_state_allowed(const struct sock *sk)
return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
if (sk_is_stream_unix(sk))
return (1 << sk->sk_state) & TCPF_ESTABLISHED;
+ if (sk_is_vsock(sk) &&
+ (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET))
+ return (1 << sk->sk_state) & TCPF_ESTABLISHED;
return true;
}
--
2.39.5
