[PATCH 4.4 26/88] VSOCK: Send reset control packet when socket is partially bound

From: Greg Kroah-Hartman
Date: Fri Jan 11 2019 - 09:17:27 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jorgen Hansen <jhansen@xxxxxxxxxx>

[ Upstream commit a915b982d8f5e4295f64b8dd37ce753874867e88 ]

If a server side socket is bound to an address, but not in the listening
state yet, incoming connection requests should receive a reset control
packet in response. However, the function used to send the reset
silently drops the reset packet if the sending socket isn't bound
to a remote address (as is the case for a bound socket not yet in
the listening state). This change fixes this by using the src
of the incoming packet as destination for the reset packet in
this case.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Reviewed-by: Adit Ranadive <aditr@xxxxxxxxxx>
Reviewed-by: Vishnu Dasa <vdasa@xxxxxxxxxx>
Signed-off-by: Jorgen Hansen <jhansen@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/vmw_vsock/vmci_transport.c | 67 ++++++++++++++++++++++++++++++-----------
1 file changed, 50 insertions(+), 17 deletions(-)

--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -273,6 +273,31 @@ vmci_transport_send_control_pkt_bh(struc
}

static int
+vmci_transport_alloc_send_control_pkt(struct sockaddr_vm *src,
+ struct sockaddr_vm *dst,
+ enum vmci_transport_packet_type type,
+ u64 size,
+ u64 mode,
+ struct vmci_transport_waiting_info *wait,
+ u16 proto,
+ struct vmci_handle handle)
+{
+ struct vmci_transport_packet *pkt;
+ int err;
+
+ pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
+ if (!pkt)
+ return -ENOMEM;
+
+ err = __vmci_transport_send_control_pkt(pkt, src, dst, type, size,
+ mode, wait, proto, handle,
+ true);
+ kfree(pkt);
+
+ return err;
+}
+
+static int
vmci_transport_send_control_pkt(struct sock *sk,
enum vmci_transport_packet_type type,
u64 size,
@@ -281,9 +306,7 @@ vmci_transport_send_control_pkt(struct s
u16 proto,
struct vmci_handle handle)
{
- struct vmci_transport_packet *pkt;
struct vsock_sock *vsk;
- int err;

vsk = vsock_sk(sk);

@@ -293,17 +316,10 @@ vmci_transport_send_control_pkt(struct s
if (!vsock_addr_bound(&vsk->remote_addr))
return -EINVAL;

- pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
- if (!pkt)
- return -ENOMEM;
-
- err = __vmci_transport_send_control_pkt(pkt, &vsk->local_addr,
- &vsk->remote_addr, type, size,
- mode, wait, proto, handle,
- true);
- kfree(pkt);
-
- return err;
+ return vmci_transport_alloc_send_control_pkt(&vsk->local_addr,
+ &vsk->remote_addr,
+ type, size, mode,
+ wait, proto, handle);
}

static int vmci_transport_send_reset_bh(struct sockaddr_vm *dst,
@@ -321,12 +337,29 @@ static int vmci_transport_send_reset_bh(
static int vmci_transport_send_reset(struct sock *sk,
struct vmci_transport_packet *pkt)
{
+ struct sockaddr_vm *dst_ptr;
+ struct sockaddr_vm dst;
+ struct vsock_sock *vsk;
+
if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
return 0;
- return vmci_transport_send_control_pkt(sk,
- VMCI_TRANSPORT_PACKET_TYPE_RST,
- 0, 0, NULL, VSOCK_PROTO_INVALID,
- VMCI_INVALID_HANDLE);
+
+ vsk = vsock_sk(sk);
+
+ if (!vsock_addr_bound(&vsk->local_addr))
+ return -EINVAL;
+
+ if (vsock_addr_bound(&vsk->remote_addr)) {
+ dst_ptr = &vsk->remote_addr;
+ } else {
+ vsock_addr_init(&dst, pkt->dg.src.context,
+ pkt->src_port);
+ dst_ptr = &dst;
+ }
+ return vmci_transport_alloc_send_control_pkt(&vsk->local_addr, dst_ptr,
+ VMCI_TRANSPORT_PACKET_TYPE_RST,
+ 0, 0, NULL, VSOCK_PROTO_INVALID,
+ VMCI_INVALID_HANDLE);
}

static int vmci_transport_send_negotiate(struct sock *sk, size_t size)