github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-10-06 18:46:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph
bfc888f045
linux/include/net/af_vsock.h
Daehyeon Ko dee44f41f2 vsock/virtio: validate packet source for connected sockets 
virtio_transport_recv_pkt() looks up sockets first by the full source and
destination tuple, then by destination only in the bound table. The
fallback is needed for listening and connecting sockets, but sockets remain
in the bound table after connect(), so it can also return a non-listening
socket.

The fallback does not validate the source address. In TCP_SYN_SENT, a
RESPONSE from an unrelated source can transition the victim socket to
TCP_ESTABLISHED while its stored remote address remains unchanged.
Subsequent RW packets from that source are delivered through the same
destination-only fallback.

This was reproduced with capability-empty processes under different UIDs.
The attacker discovered the target tuple through unprivileged AF_VSOCK
sock_diag and caused the victim socket to read 16 attacker-chosen bytes;
the intended peer-side socket read 0 of those 16 bytes.

Add vsock_check_source() to validate the transport, source port and source
CID against the peer stored in a non-listening socket. The local transport
is the CID exception because its packets are generated internally with
VMADDR_CID_LOCAL as their source, including connections using CID aliases.

Use the helper after lock_sock() in the virtio receive path.

Fixes: 06a8fc7836 ("VSOCK: Introduce virtio_vsock_common.ko")
Closes: https://lore.kernel.org/netdev/20260813121236.2328599-1-4ncienth@gmail.com/
Cc: stable@vger.kernel.org
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
Signed-off-by: Daehyeon Ko <4ncienth@gmail.com>
Link: https://patch.msgid.link/20260826003929.966160-2-4ncienth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-31 16:50:54 -07:00

334 lines
11 KiB
C
Raw Blame History

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* VMware vSockets Driver
*
* Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
*/
#ifndef __AF_VSOCK_H__
#define __AF_VSOCK_H__
#include <linux/kernel.h>
#include <linux/workqueue.h>
#include <net/netns/vsock.h>
#include <net/sock.h>
#include <uapi/linux/vm_sockets.h>
#include "vsock_addr.h"
#define LAST_RESERVED_PORT 1023
#define VSOCK_HASH_SIZE 251
extern struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
extern struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
extern spinlock_t vsock_table_lock;
#define vsock_sk(__sk) ((struct vsock_sock *)__sk)
#define sk_vsock(__vsk) (&(__vsk)->sk)
struct vsock_sock {
/* sk must be the first member. */
struct sock sk;
const struct vsock_transport *transport;
struct sockaddr_vm local_addr;
struct sockaddr_vm remote_addr;
/* Links for the global tables of bound and connected sockets. */
struct list_head bound_table;
struct list_head connected_table;
/* Accessed without the socket lock held. This means it can never be
* modified outsided of socket create or destruct.
*/
bool trusted;
bool cached_peer_allow_dgram; /* Dgram communication allowed to
* cached peer?
*/
u32 cached_peer; /* Context ID of last dgram destination check. */
const struct cred *owner;
/* Rest are SOCK_STREAM only. */
long connect_timeout;
/* Listening socket that this came from. */
struct sock *listener;
/* Used for pending list and accept queue during connection handshake.
* The listening socket is the head for both lists. Sockets created
* for connection requests are placed in the pending list until they
* are connected, at which point they are put in the accept queue list
* so they can be accepted in accept().
*/
struct list_head pending_links;
struct list_head accept_queue;
struct delayed_work connect_work;
struct delayed_work pending_work;
struct delayed_work close_work;
bool close_work_scheduled;
u32 peer_shutdown;
bool sent_request;
bool ignore_connecting_rst;
/* Protected by lock_sock(sk) */
u64 buffer_size;
u64 buffer_min_size;
u64 buffer_max_size;
/* Private to transport. */
void *trans;
};
s64 vsock_connectible_has_data(struct vsock_sock *vsk);
s64 vsock_stream_has_data(struct vsock_sock *vsk);
s64 vsock_stream_has_space(struct vsock_sock *vsk);
struct sock *vsock_create_connected(struct sock *parent);
void vsock_data_ready(struct sock *sk);
/**** TRANSPORT ****/
struct vsock_transport_recv_notify_data {
u64 data1; /* Transport-defined. */
u64 data2; /* Transport-defined. */
bool notify_on_block;
};
struct vsock_transport_send_notify_data {
u64 data1; /* Transport-defined. */
u64 data2; /* Transport-defined. */
};
/* Transport features flags */
/* Transport provides host->guest communication */
#define VSOCK_TRANSPORT_F_H2G 0x00000001
/* Transport provides guest->host communication */
#define VSOCK_TRANSPORT_F_G2H 0x00000002
/* Transport provides DGRAM communication */
#define VSOCK_TRANSPORT_F_DGRAM 0x00000004
/* Transport provides local (loopback) communication */
#define VSOCK_TRANSPORT_F_LOCAL 0x00000008
struct vsock_transport {
struct module *module;
/* Initialize/tear-down socket. */
int (*init)(struct vsock_sock *, struct vsock_sock *);
void (*destruct)(struct vsock_sock *);
void (*release)(struct vsock_sock *);
/* Cancel all pending packets sent on vsock. */
int (*cancel_pkt)(struct vsock_sock *vsk);
/* Connections. */
int (*connect)(struct vsock_sock *);
/* DGRAM. */
int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *);
int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
size_t len, int flags);
int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
struct msghdr *, size_t len);
bool (*dgram_allow)(struct vsock_sock *vsk, u32 cid, u32 port);
/* STREAM. */
/* TODO: stream_bind() */
ssize_t (*stream_dequeue)(struct vsock_sock *, struct msghdr *,
size_t len, int flags);
ssize_t (*stream_enqueue)(struct vsock_sock *, struct msghdr *,
size_t len);
s64 (*stream_has_data)(struct vsock_sock *);
s64 (*stream_has_space)(struct vsock_sock *);
u64 (*stream_rcvhiwat)(struct vsock_sock *);
bool (*stream_is_active)(struct vsock_sock *);
bool (*stream_allow)(struct vsock_sock *vsk, u32 cid, u32 port);
/* SEQ_PACKET. */
ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
int flags);
int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
size_t len);
bool (*seqpacket_allow)(struct vsock_sock *vsk, u32 remote_cid);
u32 (*seqpacket_has_data)(struct vsock_sock *vsk);
/* Notification. */
int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
int (*notify_poll_out)(struct vsock_sock *, size_t, bool *);
int (*notify_recv_init)(struct vsock_sock *, size_t,
struct vsock_transport_recv_notify_data *);
int (*notify_recv_pre_block)(struct vsock_sock *, size_t,
struct vsock_transport_recv_notify_data *);
int (*notify_recv_pre_dequeue)(struct vsock_sock *, size_t,
struct vsock_transport_recv_notify_data *);
int (*notify_recv_post_dequeue)(struct vsock_sock *, size_t,
ssize_t, bool, struct vsock_transport_recv_notify_data *);
int (*notify_send_init)(struct vsock_sock *,
struct vsock_transport_send_notify_data *);
int (*notify_send_pre_block)(struct vsock_sock *,
struct vsock_transport_send_notify_data *);
int (*notify_send_pre_enqueue)(struct vsock_sock *,
struct vsock_transport_send_notify_data *);
int (*notify_send_post_enqueue)(struct vsock_sock *, ssize_t,
struct vsock_transport_send_notify_data *);
/* sk_lock held by the caller */
void (*notify_buffer_size)(struct vsock_sock *, u64 *);
int (*notify_set_rcvlowat)(struct vsock_sock *vsk, int val);
/* SIOCOUTQ ioctl */
ssize_t (*unsent_bytes)(struct vsock_sock *vsk);
/* Shutdown. */
int (*shutdown)(struct vsock_sock *, int);
/* Addressing. */
u32 (*get_local_cid)(void);
/* Check if this transport serves a specific remote CID.
* For H2G transports: return true if the CID belongs to a registered
* guest. If not implemented, all CIDs > VMADDR_CID_HOST go to H2G.
* For G2H transports: return true if the transport can reach arbitrary
* CIDs via the hypervisor (i.e. supports the fallback overlay). VMCI
* does not implement this as it only serves CIDs 0 and 2.
*/
bool (*has_remote_cid)(struct vsock_sock *vsk, u32 remote_cid);
/* Read a single skb */
int (*read_skb)(struct vsock_sock *, skb_read_actor_t);
/* Zero-copy. */
bool (*msgzerocopy_allow)(void);
};
/**** CORE ****/
int vsock_core_register(const struct vsock_transport *t, int features);
void vsock_core_unregister(const struct vsock_transport *t);
/* The transport may downcast this to access transport-specific functions */
const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk);
/**** UTILS ****/
/* vsock_table_lock must be held */
static inline bool __vsock_in_bound_table(struct vsock_sock *vsk)
{
return !list_empty(&vsk->bound_table);
}
/* vsock_table_lock must be held */
static inline bool __vsock_in_connected_table(struct vsock_sock *vsk)
{
return !list_empty(&vsk->connected_table);
}
void vsock_add_pending(struct sock *listener, struct sock *pending);
void vsock_remove_pending(struct sock *listener, struct sock *pending);
void vsock_enqueue_accept(struct sock *listener, struct sock *connected);
void vsock_pending_to_accept(struct sock *listener, struct sock *pending);
void vsock_insert_connected(struct vsock_sock *vsk);
void vsock_remove_bound(struct vsock_sock *vsk);
void vsock_remove_connected(struct vsock_sock *vsk);
struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr);
struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
struct sockaddr_vm *dst);
struct sock *vsock_find_bound_socket_net(struct sockaddr_vm *addr,
struct net *net);
struct sock *vsock_find_connected_socket_net(struct sockaddr_vm *src,
struct sockaddr_vm *dst,
struct net *net);
bool vsock_check_source(const struct vsock_sock *vsk,
const struct vsock_transport *transport,
const struct sockaddr_vm *src);
void vsock_remove_sock(struct vsock_sock *vsk);
void vsock_for_each_connected_socket(struct vsock_transport *transport,
void (*fn)(struct sock *sk));
int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
bool vsock_find_cid(unsigned int cid);
void vsock_linger(struct sock *sk);
/**** TAP ****/
struct vsock_tap {
struct net_device *dev;
struct module *module;
struct list_head list;
};
int vsock_add_tap(struct vsock_tap *vt);
int vsock_remove_tap(struct vsock_tap *vt);
void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque);
int __vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags);
int vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags);
int __vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
size_t len, int flags);
int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
size_t len, int flags);
extern struct proto vsock_proto;
#ifdef CONFIG_BPF_SYSCALL
int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
void __init vsock_bpf_build_proto(void);
#else
static inline void __init vsock_bpf_build_proto(void)
{}
#endif
static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t)
{
return t->msgzerocopy_allow && t->msgzerocopy_allow();
}
static inline enum vsock_net_mode vsock_net_mode(struct net *net)
{
if (!net)
return VSOCK_NET_MODE_GLOBAL;
return READ_ONCE(net->vsock.mode);
}
static inline bool vsock_net_mode_global(struct vsock_sock *vsk)
{
return vsock_net_mode(sock_net(sk_vsock(vsk))) == VSOCK_NET_MODE_GLOBAL;
}
static inline bool vsock_net_set_child_mode(struct net *net,
enum vsock_net_mode mode)
{
int new_locked = mode + 1;
int old_locked = 0; /* unlocked */
if (try_cmpxchg(&net->vsock.child_ns_mode_locked,
&old_locked, new_locked)) {
WRITE_ONCE(net->vsock.child_ns_mode, mode);
return true;
}
return old_locked == new_locked;
}
static inline enum vsock_net_mode vsock_net_child_mode(struct net *net)
{
return READ_ONCE(net->vsock.child_ns_mode);
}
/* Return true if two namespaces pass the mode rules. Otherwise, return false.
*
* A NULL namespace is treated as VSOCK_NET_MODE_GLOBAL.
*
* Read more about modes in the comment header of net/vmw_vsock/af_vsock.c.
*/
static inline bool vsock_net_check_mode(struct net *ns0, struct net *ns1)
{
enum vsock_net_mode mode0, mode1;
/* Any vsocks within the same network namespace are always reachable,
* regardless of the mode.
*/
if (net_eq(ns0, ns1))
return true;
mode0 = vsock_net_mode(ns0);
mode1 = vsock_net_mode(ns1);
/* Different namespaces are only reachable if they are both
* global mode.
*/
return mode0 == VSOCK_NET_MODE_GLOBAL && mode0 == mode1;
}
#endif /* __AF_VSOCK_H__ */
Reference in New Issue View Git Blame Copy Permalink