mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
6659061045
In preparation for users of the "install a received file" logic outside of net/ (pidfd and seccomp), relocate and rename __scm_install_fd() from net/core/scm.c to __receive_fd() in fs/file.c, and provide a wrapper named receive_fd_user(), as future patches will change the interface to __receive_fd(). Additionally add a comment to fd_install() as a counterpoint to how __receive_fd() interacts with fput(). Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Dmitry Kadashev <dkadashev@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Sargun Dhillon <sargun@sargun.me> Cc: Ido Schimmel <idosch@idosch.org> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: linux-fsdevel@vger.kernel.org Cc: netdev@vger.kernel.org Reviewed-by: Sargun Dhillon <sargun@sargun.me> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Kees Cook <keescook@chromium.org>
146 lines
3.5 KiB
C
146 lines
3.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __LINUX_NET_SCM_H
|
|
#define __LINUX_NET_SCM_H
|
|
|
|
#include <linux/limits.h>
|
|
#include <linux/net.h>
|
|
#include <linux/cred.h>
|
|
#include <linux/security.h>
|
|
#include <linux/pid.h>
|
|
#include <linux/nsproxy.h>
|
|
#include <linux/sched/signal.h>
|
|
|
|
/* Well, we should have at least one descriptor open
|
|
* to accept passed FDs 8)
|
|
*/
|
|
#define SCM_MAX_FD 253
|
|
|
|
struct scm_creds {
|
|
u32 pid;
|
|
kuid_t uid;
|
|
kgid_t gid;
|
|
};
|
|
|
|
struct scm_fp_list {
|
|
short count;
|
|
short max;
|
|
struct user_struct *user;
|
|
struct file *fp[SCM_MAX_FD];
|
|
};
|
|
|
|
struct scm_cookie {
|
|
struct pid *pid; /* Skb credentials */
|
|
struct scm_fp_list *fp; /* Passed files */
|
|
struct scm_creds creds; /* Skb credentials */
|
|
#ifdef CONFIG_SECURITY_NETWORK
|
|
u32 secid; /* Passed security ID */
|
|
#endif
|
|
};
|
|
|
|
void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
|
|
void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
|
|
int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
|
|
void __scm_destroy(struct scm_cookie *scm);
|
|
struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
|
|
|
|
#ifdef CONFIG_SECURITY_NETWORK
|
|
static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
|
|
{
|
|
security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
|
|
}
|
|
#else
|
|
static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
|
|
{ }
|
|
#endif /* CONFIG_SECURITY_NETWORK */
|
|
|
|
static __inline__ void scm_set_cred(struct scm_cookie *scm,
|
|
struct pid *pid, kuid_t uid, kgid_t gid)
|
|
{
|
|
scm->pid = get_pid(pid);
|
|
scm->creds.pid = pid_vnr(pid);
|
|
scm->creds.uid = uid;
|
|
scm->creds.gid = gid;
|
|
}
|
|
|
|
static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
|
|
{
|
|
put_pid(scm->pid);
|
|
scm->pid = NULL;
|
|
}
|
|
|
|
static __inline__ void scm_destroy(struct scm_cookie *scm)
|
|
{
|
|
scm_destroy_cred(scm);
|
|
if (scm->fp)
|
|
__scm_destroy(scm);
|
|
}
|
|
|
|
static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
|
|
struct scm_cookie *scm, bool forcecreds)
|
|
{
|
|
memset(scm, 0, sizeof(*scm));
|
|
scm->creds.uid = INVALID_UID;
|
|
scm->creds.gid = INVALID_GID;
|
|
if (forcecreds)
|
|
scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
|
|
unix_get_peersec_dgram(sock, scm);
|
|
if (msg->msg_controllen <= 0)
|
|
return 0;
|
|
return __scm_send(sock, msg, scm);
|
|
}
|
|
|
|
#ifdef CONFIG_SECURITY_NETWORK
|
|
static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
|
|
{
|
|
char *secdata;
|
|
u32 seclen;
|
|
int err;
|
|
|
|
if (test_bit(SOCK_PASSSEC, &sock->flags)) {
|
|
err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
|
|
|
|
if (!err) {
|
|
put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
|
|
security_release_secctx(secdata, seclen);
|
|
}
|
|
}
|
|
}
|
|
#else
|
|
static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
|
|
{ }
|
|
#endif /* CONFIG_SECURITY_NETWORK */
|
|
|
|
static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
|
|
struct scm_cookie *scm, int flags)
|
|
{
|
|
if (!msg->msg_control) {
|
|
if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
|
|
msg->msg_flags |= MSG_CTRUNC;
|
|
scm_destroy(scm);
|
|
return;
|
|
}
|
|
|
|
if (test_bit(SOCK_PASSCRED, &sock->flags)) {
|
|
struct user_namespace *current_ns = current_user_ns();
|
|
struct ucred ucreds = {
|
|
.pid = scm->creds.pid,
|
|
.uid = from_kuid_munged(current_ns, scm->creds.uid),
|
|
.gid = from_kgid_munged(current_ns, scm->creds.gid),
|
|
};
|
|
put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds);
|
|
}
|
|
|
|
scm_destroy_cred(scm);
|
|
|
|
scm_passec(sock, msg, scm);
|
|
|
|
if (!scm->fp)
|
|
return;
|
|
|
|
scm_detach_fds(msg, scm);
|
|
}
|
|
|
|
|
|
#endif /* __LINUX_NET_SCM_H */
|
|
|