Contributors: 40
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Linus Torvalds (pre-git) |
1181 |
44.25% |
45 |
38.79% |
| Eric W. Biedermann |
296 |
11.09% |
6 |
5.17% |
| Christoph Hellwig |
225 |
8.43% |
3 |
2.59% |
| Kuniyuki Iwashima |
219 |
8.21% |
9 |
7.76% |
| Deepa Dinamani |
159 |
5.96% |
1 |
0.86% |
| Alexander Mikhalitsyn |
157 |
5.88% |
3 |
2.59% |
| Eric Dumazet |
115 |
4.31% |
8 |
6.90% |
| Stanislav Fomichev |
52 |
1.95% |
1 |
0.86% |
| Catherine Zhang |
47 |
1.76% |
2 |
1.72% |
| Hannes Frederic Sowa |
41 |
1.54% |
1 |
0.86% |
| David Howells |
27 |
1.01% |
2 |
1.72% |
| Benjamin LaHaise |
24 |
0.90% |
1 |
0.86% |
| Pavel Begunkov |
21 |
0.79% |
1 |
0.86% |
| Casey Schaufler |
14 |
0.52% |
2 |
1.72% |
| Kevin Brodsky |
9 |
0.34% |
1 |
0.86% |
| Al Viro |
9 |
0.34% |
3 |
2.59% |
| Wei Yongjun |
8 |
0.30% |
1 |
0.86% |
| Daniel Borkmann |
6 |
0.22% |
1 |
0.86% |
| Pavel Emelyanov |
6 |
0.22% |
1 |
0.86% |
| Herbert Xu |
4 |
0.15% |
1 |
0.86% |
| Arnd Bergmann |
4 |
0.15% |
1 |
0.86% |
| Daniel Wagner |
3 |
0.11% |
1 |
0.86% |
| Greg Kroah-Hartman |
3 |
0.11% |
1 |
0.86% |
| Gu Zheng |
3 |
0.11% |
1 |
0.86% |
| Ingo Molnar |
3 |
0.11% |
1 |
0.86% |
| Stephen Rothwell |
3 |
0.11% |
1 |
0.86% |
| Randy Dunlap |
3 |
0.11% |
1 |
0.86% |
| Patrick Ohly |
3 |
0.11% |
1 |
0.86% |
| Serge E. Hallyn |
3 |
0.11% |
1 |
0.86% |
| Kees Cook |
3 |
0.11% |
2 |
1.72% |
| Andrew Lutomirski |
3 |
0.11% |
1 |
0.86% |
| Arnaldo Carvalho de Melo |
3 |
0.11% |
2 |
1.72% |
| Hideaki Yoshifuji / 吉藤英明 |
2 |
0.07% |
1 |
0.86% |
| Vasily Averin |
2 |
0.07% |
1 |
0.86% |
| Linus Torvalds |
2 |
0.07% |
2 |
1.72% |
| Thomas Gleixner |
2 |
0.07% |
1 |
0.86% |
| Christian Brauner |
1 |
0.04% |
1 |
0.86% |
| Jens Axboe |
1 |
0.04% |
1 |
0.86% |
| Stephen Hemminger |
1 |
0.04% |
1 |
0.86% |
| David S. Miller |
1 |
0.04% |
1 |
0.86% |
| Total |
2669 |
|
116 |
|
// SPDX-License-Identifier: GPL-2.0-or-later
/* scm.c - Socket level control messages processing.
*
* Author: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
* Alignment and value checking mods by Craig Metz
*/
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/sched/user.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/stat.h>
#include <linux/socket.h>
#include <linux/file.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/security.h>
#include <linux/pid_namespace.h>
#include <linux/pid.h>
#include <linux/nsproxy.h>
#include <linux/slab.h>
#include <linux/errqueue.h>
#include <linux/io_uring.h>
#include <linux/uaccess.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/compat.h>
#include <net/scm.h>
#include <net/cls_cgroup.h>
#include <net/af_unix.h>
/*
* Only allow a user to send credentials, that they could set with
* setu(g)id.
*/
static __inline__ int scm_check_creds(struct ucred *creds)
{
const struct cred *cred = current_cred();
kuid_t uid = make_kuid(cred->user_ns, creds->uid);
kgid_t gid = make_kgid(cred->user_ns, creds->gid);
if (!uid_valid(uid) || !gid_valid(gid))
return -EINVAL;
if ((creds->pid == task_tgid_vnr(current) ||
ns_capable(task_active_pid_ns(current)->user_ns, CAP_SYS_ADMIN)) &&
((uid_eq(uid, cred->uid) || uid_eq(uid, cred->euid) ||
uid_eq(uid, cred->suid)) || ns_capable(cred->user_ns, CAP_SETUID)) &&
((gid_eq(gid, cred->gid) || gid_eq(gid, cred->egid) ||
gid_eq(gid, cred->sgid)) || ns_capable(cred->user_ns, CAP_SETGID))) {
return 0;
}
return -EPERM;
}
static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
{
int *fdp = (int*)CMSG_DATA(cmsg);
struct scm_fp_list *fpl = *fplp;
struct file **fpp;
int i, num;
num = (cmsg->cmsg_len - sizeof(struct cmsghdr))/sizeof(int);
if (num <= 0)
return 0;
if (num > SCM_MAX_FD)
return -EINVAL;
if (!fpl)
{
fpl = kmalloc(sizeof(struct scm_fp_list), GFP_KERNEL_ACCOUNT);
if (!fpl)
return -ENOMEM;
*fplp = fpl;
fpl->count = 0;
fpl->count_unix = 0;
fpl->max = SCM_MAX_FD;
fpl->user = NULL;
#if IS_ENABLED(CONFIG_UNIX)
fpl->inflight = false;
fpl->dead = false;
fpl->edges = NULL;
INIT_LIST_HEAD(&fpl->vertices);
#endif
}
fpp = &fpl->fp[fpl->count];
if (fpl->count + num > fpl->max)
return -EINVAL;
/*
* Verify the descriptors and increment the usage count.
*/
for (i=0; i< num; i++)
{
int fd = fdp[i];
struct file *file;
if (fd < 0 || !(file = fget_raw(fd)))
return -EBADF;
/* don't allow io_uring files */
if (io_is_uring_fops(file)) {
fput(file);
return -EINVAL;
}
if (unix_get_socket(file))
fpl->count_unix++;
*fpp++ = file;
fpl->count++;
}
if (!fpl->user)
fpl->user = get_uid(current_user());
return num;
}
void __scm_destroy(struct scm_cookie *scm)
{
struct scm_fp_list *fpl = scm->fp;
int i;
if (fpl) {
scm->fp = NULL;
for (i=fpl->count-1; i>=0; i--)
fput(fpl->fp[i]);
free_uid(fpl->user);
kfree(fpl);
}
}
EXPORT_SYMBOL(__scm_destroy);
int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
{
const struct proto_ops *ops = READ_ONCE(sock->ops);
struct cmsghdr *cmsg;
int err;
for_each_cmsghdr(cmsg, msg) {
err = -EINVAL;
/* Verify that cmsg_len is at least sizeof(struct cmsghdr) */
/* The first check was omitted in <= 2.2.5. The reasoning was
that parser checks cmsg_len in any case, so that
additional check would be work duplication.
But if cmsg_level is not SOL_SOCKET, we do not check
for too short ancillary data object at all! Oops.
OK, let's add it...
*/
if (!CMSG_OK(msg, cmsg))
goto error;
if (cmsg->cmsg_level != SOL_SOCKET)
continue;
switch (cmsg->cmsg_type)
{
case SCM_RIGHTS:
if (!ops || ops->family != PF_UNIX)
goto error;
err=scm_fp_copy(cmsg, &p->fp);
if (err<0)
goto error;
break;
case SCM_CREDENTIALS:
{
struct ucred creds;
kuid_t uid;
kgid_t gid;
if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
goto error;
memcpy(&creds, CMSG_DATA(cmsg), sizeof(struct ucred));
err = scm_check_creds(&creds);
if (err)
goto error;
p->creds.pid = creds.pid;
if (!p->pid || pid_vnr(p->pid) != creds.pid) {
struct pid *pid;
err = -ESRCH;
pid = find_get_pid(creds.pid);
if (!pid)
goto error;
put_pid(p->pid);
p->pid = pid;
}
err = -EINVAL;
uid = make_kuid(current_user_ns(), creds.uid);
gid = make_kgid(current_user_ns(), creds.gid);
if (!uid_valid(uid) || !gid_valid(gid))
goto error;
p->creds.uid = uid;
p->creds.gid = gid;
break;
}
default:
goto error;
}
}
if (p->fp && !p->fp->count)
{
kfree(p->fp);
p->fp = NULL;
}
return 0;
error:
scm_destroy(p);
return err;
}
EXPORT_SYMBOL(__scm_send);
int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
{
int cmlen = CMSG_LEN(len);
if (msg->msg_flags & MSG_CMSG_COMPAT)
return put_cmsg_compat(msg, level, type, len, data);
if (!msg->msg_control || msg->msg_controllen < sizeof(struct cmsghdr)) {
msg->msg_flags |= MSG_CTRUNC;
return 0; /* XXX: return error? check spec. */
}
if (msg->msg_controllen < cmlen) {
msg->msg_flags |= MSG_CTRUNC;
cmlen = msg->msg_controllen;
}
if (msg->msg_control_is_user) {
struct cmsghdr __user *cm = msg->msg_control_user;
check_object_size(data, cmlen - sizeof(*cm), true);
if (!user_write_access_begin(cm, cmlen))
goto efault;
unsafe_put_user(cmlen, &cm->cmsg_len, efault_end);
unsafe_put_user(level, &cm->cmsg_level, efault_end);
unsafe_put_user(type, &cm->cmsg_type, efault_end);
unsafe_copy_to_user(CMSG_USER_DATA(cm), data,
cmlen - sizeof(*cm), efault_end);
user_write_access_end();
} else {
struct cmsghdr *cm = msg->msg_control;
cm->cmsg_level = level;
cm->cmsg_type = type;
cm->cmsg_len = cmlen;
memcpy(CMSG_DATA(cm), data, cmlen - sizeof(*cm));
}
cmlen = min(CMSG_SPACE(len), msg->msg_controllen);
if (msg->msg_control_is_user)
msg->msg_control_user += cmlen;
else
msg->msg_control += cmlen;
msg->msg_controllen -= cmlen;
return 0;
efault_end:
user_write_access_end();
efault:
return -EFAULT;
}
EXPORT_SYMBOL(put_cmsg);
int put_cmsg_notrunc(struct msghdr *msg, int level, int type, int len,
void *data)
{
/* Don't produce truncated CMSGs */
if (!msg->msg_control || msg->msg_controllen < CMSG_LEN(len))
return -ETOOSMALL;
return put_cmsg(msg, level, type, len, data);
}
void put_cmsg_scm_timestamping64(struct msghdr *msg, struct scm_timestamping_internal *tss_internal)
{
struct scm_timestamping64 tss;
int i;
for (i = 0; i < ARRAY_SIZE(tss.ts); i++) {
tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec;
tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec;
}
put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_NEW, sizeof(tss), &tss);
}
EXPORT_SYMBOL(put_cmsg_scm_timestamping64);
void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_internal *tss_internal)
{
struct scm_timestamping tss;
int i;
for (i = 0; i < ARRAY_SIZE(tss.ts); i++) {
tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec;
tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec;
}
put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_OLD, sizeof(tss), &tss);
}
EXPORT_SYMBOL(put_cmsg_scm_timestamping);
static int scm_max_fds(struct msghdr *msg)
{
if (msg->msg_controllen <= sizeof(struct cmsghdr))
return 0;
return (msg->msg_controllen - sizeof(struct cmsghdr)) / sizeof(int);
}
void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
{
struct cmsghdr __user *cm =
(__force struct cmsghdr __user *)msg->msg_control_user;
unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
int fdmax = min_t(int, scm_max_fds(msg), scm->fp->count);
int __user *cmsg_data = CMSG_USER_DATA(cm);
int err = 0, i;
/* no use for FD passing from kernel space callers */
if (WARN_ON_ONCE(!msg->msg_control_is_user))
return;
if (msg->msg_flags & MSG_CMSG_COMPAT) {
scm_detach_fds_compat(msg, scm);
return;
}
for (i = 0; i < fdmax; i++) {
err = scm_recv_one_fd(scm->fp->fp[i], cmsg_data + i, o_flags);
if (err < 0)
break;
}
if (i > 0) {
int cmlen = CMSG_LEN(i * sizeof(int));
err = put_user(SOL_SOCKET, &cm->cmsg_level);
if (!err)
err = put_user(SCM_RIGHTS, &cm->cmsg_type);
if (!err)
err = put_user(cmlen, &cm->cmsg_len);
if (!err) {
cmlen = CMSG_SPACE(i * sizeof(int));
if (msg->msg_controllen < cmlen)
cmlen = msg->msg_controllen;
msg->msg_control_user += cmlen;
msg->msg_controllen -= cmlen;
}
}
if (i < scm->fp->count || (scm->fp->count && fdmax <= 0))
msg->msg_flags |= MSG_CTRUNC;
/*
* All of the files that fit in the message have had their usage counts
* incremented, so we just free the list.
*/
__scm_destroy(scm);
}
EXPORT_SYMBOL(scm_detach_fds);
struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
{
struct scm_fp_list *new_fpl;
int i;
if (!fpl)
return NULL;
new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]),
GFP_KERNEL_ACCOUNT);
if (new_fpl) {
for (i = 0; i < fpl->count; i++)
get_file(fpl->fp[i]);
new_fpl->max = new_fpl->count;
new_fpl->user = get_uid(fpl->user);
#if IS_ENABLED(CONFIG_UNIX)
new_fpl->inflight = false;
new_fpl->edges = NULL;
INIT_LIST_HEAD(&new_fpl->vertices);
#endif
}
return new_fpl;
}
EXPORT_SYMBOL(scm_fp_dup);
#ifdef CONFIG_SECURITY_NETWORK
static void scm_passec(struct sock *sk, struct msghdr *msg, struct scm_cookie *scm)
{
struct lsm_context ctx;
int err;
if (sk->sk_scm_security) {
err = security_secid_to_secctx(scm->secid, &ctx);
if (err >= 0) {
put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, ctx.len,
ctx.context);
security_release_secctx(&ctx);
}
}
}
static bool scm_has_secdata(struct sock *sk)
{
return sk->sk_scm_security;
}
#else
static void scm_passec(struct sock *sk, struct msghdr *msg, struct scm_cookie *scm)
{
}
static bool scm_has_secdata(struct sock *sk)
{
return false;
}
#endif
static void scm_pidfd_recv(struct msghdr *msg, struct scm_cookie *scm)
{
struct file *pidfd_file = NULL;
int len, pidfd;
/* put_cmsg() doesn't return an error if CMSG is truncated,
* that's why we need to opencode these checks here.
*/
if (msg->msg_flags & MSG_CMSG_COMPAT)
len = sizeof(struct compat_cmsghdr) + sizeof(int);
else
len = sizeof(struct cmsghdr) + sizeof(int);
if (msg->msg_controllen < len) {
msg->msg_flags |= MSG_CTRUNC;
return;
}
if (!scm->pid)
return;
pidfd = pidfd_prepare(scm->pid, 0, &pidfd_file);
if (put_cmsg(msg, SOL_SOCKET, SCM_PIDFD, sizeof(int), &pidfd)) {
if (pidfd_file) {
put_unused_fd(pidfd);
fput(pidfd_file);
}
return;
}
if (pidfd_file)
fd_install(pidfd, pidfd_file);
}
static bool __scm_recv_common(struct sock *sk, struct msghdr *msg,
struct scm_cookie *scm, int flags)
{
if (!msg->msg_control) {
if (sk->sk_scm_credentials || sk->sk_scm_pidfd ||
scm->fp || scm_has_secdata(sk))
msg->msg_flags |= MSG_CTRUNC;
scm_destroy(scm);
return false;
}
if (sk->sk_scm_credentials) {
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_passec(sk, msg, scm);
if (scm->fp)
scm_detach_fds(msg, scm);
return true;
}
void scm_recv(struct socket *sock, struct msghdr *msg,
struct scm_cookie *scm, int flags)
{
if (!__scm_recv_common(sock->sk, msg, scm, flags))
return;
scm_destroy_cred(scm);
}
EXPORT_SYMBOL(scm_recv);
void scm_recv_unix(struct socket *sock, struct msghdr *msg,
struct scm_cookie *scm, int flags)
{
if (!__scm_recv_common(sock->sk, msg, scm, flags))
return;
if (sock->sk->sk_scm_pidfd)
scm_pidfd_recv(msg, scm);
scm_destroy_cred(scm);
}