[linux-block.git] / net / core / scm.c

// 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/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>


/*
 *	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);
		if (!fpl)
			return -ENOMEM;
		*fplp = fpl;
		fpl->count = 0;
		fpl->max = SCM_MAX_FD;
		fpl->user = NULL;
	}
	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;
		*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)
{
	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 (!sock->ops || sock->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)
{
	struct cmsghdr __user *cm
		= (__force struct cmsghdr __user *)msg->msg_control;
	struct cmsghdr cmhdr;
	int cmlen = CMSG_LEN(len);
	int err;

	if (MSG_CMSG_COMPAT & msg->msg_flags)
		return put_cmsg_compat(msg, level, type, len, data);

	if (cm==NULL || msg->msg_controllen < sizeof(*cm)) {
		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;
	}
	cmhdr.cmsg_level = level;
	cmhdr.cmsg_type = type;
	cmhdr.cmsg_len = cmlen;

	err = -EFAULT;
	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
		goto out;
	if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
		goto out;
	cmlen = CMSG_SPACE(len);
	if (msg->msg_controllen < cmlen)
		cmlen = msg->msg_controllen;
	msg->msg_control += cmlen;
	msg->msg_controllen -= cmlen;
	err = 0;
out:
	return err;
}
EXPORT_SYMBOL(put_cmsg);

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] = timespec64_to_timespec(tss_internal->ts[i]);

	put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_OLD, sizeof(tss), &tss);
}
EXPORT_SYMBOL(put_cmsg_scm_timestamping);

void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
{
	struct cmsghdr __user *cm
		= (__force struct cmsghdr __user*)msg->msg_control;

	int fdmax = 0;
	int fdnum = scm->fp->count;
	struct file **fp = scm->fp->fp;
	int __user *cmfptr;
	int err = 0, i;

	if (MSG_CMSG_COMPAT & msg->msg_flags) {
		scm_detach_fds_compat(msg, scm);
		return;
	}

	if (msg->msg_controllen > sizeof(struct cmsghdr))
		fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr))
			 / sizeof(int));

	if (fdnum < fdmax)
		fdmax = fdnum;

	for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
	     i++, cmfptr++)
	{
		struct socket *sock;
		int new_fd;
		err = security_file_receive(fp[i]);
		if (err)
			break;
		err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & msg->msg_flags
					  ? O_CLOEXEC : 0);
		if (err < 0)
			break;
		new_fd = err;
		err = put_user(new_fd, cmfptr);
		if (err) {
			put_unused_fd(new_fd);
			break;
		}
		/* Bump the usage count and install the file. */
		sock = sock_from_file(fp[i], &err);
		if (sock) {
			sock_update_netprioidx(&sock->sk->sk_cgrp_data);
			sock_update_classid(&sock->sk->sk_cgrp_data);
		}
		fd_install(new_fd, get_file(fp[i]));
	}

	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 += cmlen;
			msg->msg_controllen -= cmlen;
		}
	}
	if (i < fdnum || (fdnum && 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);
	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);
	}
	return new_fpl;
}
EXPORT_SYMBOL(scm_fp_dup);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/* scm.c - Socket level control messages processing.
	3	*
	4	* Author: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	5	* Alignment and value checking mods by Craig Metz
1da177e4 LT	6	*/
	7
	8	#include <linux/module.h>
	9	#include <linux/signal.h>
4fc268d2	10	#include <linux/capability.h>
1da177e4 LT	11	#include <linux/errno.h>
1da177e4 LT	12	#include <linux/sched.h>
8703e8a4	13	#include <linux/sched/user.h>
1da177e4 LT	14	#include <linux/mm.h>
1da177e4 LT	15	#include <linux/kernel.h>
1da177e4 LT	16	#include <linux/stat.h>
	17	#include <linux/socket.h>
	18	#include <linux/file.h>
	19	#include <linux/fcntl.h>
	20	#include <linux/net.h>
	21	#include <linux/interrupt.h>
	22	#include <linux/netdevice.h>
	23	#include <linux/security.h>
92f28d97	24	#include <linux/pid_namespace.h>
b488893a PE	25	#include <linux/pid.h>
b488893a PE	26	#include <linux/nsproxy.h>
5a0e3ad6	27	#include <linux/slab.h>
9718475e	28	#include <linux/errqueue.h>
1da177e4	29
7c0f6ba6	30	#include <linux/uaccess.h>
1da177e4 LT	31
	32	#include <net/protocol.h>
	33	#include <linux/skbuff.h>
	34	#include <net/sock.h>
	35	#include <net/compat.h>
	36	#include <net/scm.h>
d8429506	37	#include <net/cls_cgroup.h>
1da177e4 LT	38
	39
	40	/*
4ec93edb	41	* Only allow a user to send credentials, that they could set with
1da177e4 LT	42	* setu(g)id.
	43	*/
	44
	45	static __inline__ int scm_check_creds(struct ucred *creds)
	46	{
86a264ab	47	const struct cred *cred = current_cred();
b2e4f544 EB	48	kuid_t uid = make_kuid(cred->user_ns, creds->uid);
	49	kgid_t gid = make_kgid(cred->user_ns, creds->gid);
	50
	51	if (!uid_valid(uid) \|\| !gid_valid(gid))
	52	return -EINVAL;
b6dff3ec	53
92f28d97	54	if ((creds->pid == task_tgid_vnr(current) \|\|
d661684c	55	ns_capable(task_active_pid_ns(current)->user_ns, CAP_SYS_ADMIN)) &&
b2e4f544	56	((uid_eq(uid, cred->uid) \|\| uid_eq(uid, cred->euid) \|\|
c7b96acf	57	uid_eq(uid, cred->suid)) \|\| ns_capable(cred->user_ns, CAP_SETUID)) &&
b2e4f544	58	((gid_eq(gid, cred->gid) \|\| gid_eq(gid, cred->egid) \|\|
c7b96acf	59	gid_eq(gid, cred->sgid)) \|\| ns_capable(cred->user_ns, CAP_SETGID))) {
1da177e4 LT	60	return 0;
	61	}
	62	return -EPERM;
	63	}
	64
	65	static int scm_fp_copy(struct cmsghdr cmsg, struct scm_fp_list *fplp)
	66	{
	67	int fdp = (int)CMSG_DATA(cmsg);
	68	struct scm_fp_list fpl = fplp;
	69	struct file **fpp;
	70	int i, num;
	71
1ff8cebf	72	num = (cmsg->cmsg_len - sizeof(struct cmsghdr))/sizeof(int);
1da177e4 LT	73
	74	if (num <= 0)
	75	return 0;
	76
	77	if (num > SCM_MAX_FD)
	78	return -EINVAL;
	79
	80	if (!fpl)
	81	{
	82	fpl = kmalloc(sizeof(struct scm_fp_list), GFP_KERNEL);
	83	if (!fpl)
	84	return -ENOMEM;
	85	*fplp = fpl;
	86	fpl->count = 0;
bba14de9	87	fpl->max = SCM_MAX_FD;
415e3d3e	88	fpl->user = NULL;
1da177e4 LT	89	}
	90	fpp = &fpl->fp[fpl->count];
	91
bba14de9	92	if (fpl->count + num > fpl->max)
1da177e4	93	return -EINVAL;
4ec93edb	94
1da177e4 LT	95	/*
	96	* Verify the descriptors and increment the usage count.
	97	*/
4ec93edb	98
1da177e4 LT	99	for (i=0; i< num; i++)
	100	{
	101	int fd = fdp[i];
	102	struct file *file;
	103
326be7b4	104	if (fd < 0 \|\| !(file = fget_raw(fd)))
1da177e4 LT	105	return -EBADF;
	106	*fpp++ = file;
	107	fpl->count++;
	108	}
415e3d3e HFS	109
	110	if (!fpl->user)
	111	fpl->user = get_uid(current_user());
	112
1da177e4 LT	113	return num;
	114	}
	115
	116	void __scm_destroy(struct scm_cookie *scm)
	117	{
	118	struct scm_fp_list *fpl = scm->fp;
	119	int i;
	120
	121	if (fpl) {
	122	scm->fp = NULL;
6120d3db AV	123	for (i=fpl->count-1; i>=0; i--)
6120d3db AV	124	fput(fpl->fp[i]);
415e3d3e	125	free_uid(fpl->user);
6120d3db	126	kfree(fpl);
1da177e4 LT	127	}
1da177e4 LT	128	}
9e34a5b5	129	EXPORT_SYMBOL(__scm_destroy);
1da177e4 LT	130
	131	int __scm_send(struct socket sock, struct msghdr msg, struct scm_cookie *p)
	132	{
	133	struct cmsghdr *cmsg;
	134	int err;
	135
f95b414e	136	for_each_cmsghdr(cmsg, msg) {
1da177e4 LT	137	err = -EINVAL;
	138
	139	/* Verify that cmsg_len is at least sizeof(struct cmsghdr) */
	140	/* The first check was omitted in <= 2.2.5. The reasoning was
	141	that parser checks cmsg_len in any case, so that
	142	additional check would be work duplication.
4ec93edb	143	But if cmsg_level is not SOL_SOCKET, we do not check
1da177e4 LT	144	for too short ancillary data object at all! Oops.
	145	OK, let's add it...
	146	*/
	147	if (!CMSG_OK(msg, cmsg))
	148	goto error;
	149
	150	if (cmsg->cmsg_level != SOL_SOCKET)
	151	continue;
	152
	153	switch (cmsg->cmsg_type)
	154	{
	155	case SCM_RIGHTS:
76dadd76 EB	156	if (!sock->ops \|\| sock->ops->family != PF_UNIX)
76dadd76 EB	157	goto error;
1da177e4 LT	158	err=scm_fp_copy(cmsg, &p->fp);
	159	if (err<0)
	160	goto error;
	161	break;
	162	case SCM_CREDENTIALS:
b2e4f544	163	{
dbe9a417	164	struct ucred creds;
b2e4f544 EB	165	kuid_t uid;
b2e4f544 EB	166	kgid_t gid;
1da177e4 LT	167	if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
1da177e4 LT	168	goto error;
dbe9a417 EB	169	memcpy(&creds, CMSG_DATA(cmsg), sizeof(struct ucred));
dbe9a417 EB	170	err = scm_check_creds(&creds);
1da177e4 LT	171	if (err)
1da177e4 LT	172	goto error;
257b5358	173
dbe9a417 EB	174	p->creds.pid = creds.pid;
dbe9a417 EB	175	if (!p->pid \|\| pid_vnr(p->pid) != creds.pid) {
257b5358 EB	176	struct pid *pid;
257b5358 EB	177	err = -ESRCH;
dbe9a417	178	pid = find_get_pid(creds.pid);
257b5358 EB	179	if (!pid)
	180	goto error;
	181	put_pid(p->pid);
	182	p->pid = pid;
	183	}
	184
b2e4f544	185	err = -EINVAL;
dbe9a417 EB	186	uid = make_kuid(current_user_ns(), creds.uid);
dbe9a417 EB	187	gid = make_kgid(current_user_ns(), creds.gid);
b2e4f544 EB	188	if (!uid_valid(uid) \|\| !gid_valid(gid))
	189	goto error;
	190
dbe9a417 EB	191	p->creds.uid = uid;
dbe9a417 EB	192	p->creds.gid = gid;
1da177e4	193	break;
b2e4f544	194	}
1da177e4 LT	195	default:
	196	goto error;
	197	}
	198	}
	199
	200	if (p->fp && !p->fp->count)
	201	{
	202	kfree(p->fp);
	203	p->fp = NULL;
	204	}
	205	return 0;
4ec93edb	206
1da177e4 LT	207	error:
	208	scm_destroy(p);
	209	return err;
	210	}
9e34a5b5	211	EXPORT_SYMBOL(__scm_send);
1da177e4 LT	212
	213	int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
	214	{
cfcabdcc SH	215	struct cmsghdr __user *cm
cfcabdcc SH	216	= (__force struct cmsghdr __user *)msg->msg_control;
1da177e4 LT	217	struct cmsghdr cmhdr;
	218	int cmlen = CMSG_LEN(len);
	219	int err;
	220
	221	if (MSG_CMSG_COMPAT & msg->msg_flags)
	222	return put_cmsg_compat(msg, level, type, len, data);
	223
	224	if (cm==NULL \|\| msg->msg_controllen < sizeof(*cm)) {
	225	msg->msg_flags \|= MSG_CTRUNC;
	226	return 0; /* XXX: return error? check spec. */
	227	}
	228	if (msg->msg_controllen < cmlen) {
	229	msg->msg_flags \|= MSG_CTRUNC;
	230	cmlen = msg->msg_controllen;
	231	}
	232	cmhdr.cmsg_level = level;
	233	cmhdr.cmsg_type = type;
	234	cmhdr.cmsg_len = cmlen;
	235
	236	err = -EFAULT;
	237	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
4ec93edb	238	goto out;
1da177e4 LT	239	if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
	240	goto out;
	241	cmlen = CMSG_SPACE(len);
1ac70e7a WY	242	if (msg->msg_controllen < cmlen)
1ac70e7a WY	243	cmlen = msg->msg_controllen;
1da177e4 LT	244	msg->msg_control += cmlen;
	245	msg->msg_controllen -= cmlen;
	246	err = 0;
	247	out:
	248	return err;
	249	}
9e34a5b5	250	EXPORT_SYMBOL(put_cmsg);
1da177e4	251
9718475e DD	252	void put_cmsg_scm_timestamping64(struct msghdr msg, struct scm_timestamping_internal tss_internal)
	253	{
	254	struct scm_timestamping64 tss;
	255	int i;
	256
	257	for (i = 0; i < ARRAY_SIZE(tss.ts); i++) {
	258	tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec;
	259	tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec;
	260	}
	261
	262	put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_NEW, sizeof(tss), &tss);
	263	}
	264	EXPORT_SYMBOL(put_cmsg_scm_timestamping64);
	265
	266	void put_cmsg_scm_timestamping(struct msghdr msg, struct scm_timestamping_internal tss_internal)
	267	{
	268	struct scm_timestamping tss;
	269	int i;
	270
	271	for (i = 0; i < ARRAY_SIZE(tss.ts); i++)
	272	tss.ts[i] = timespec64_to_timespec(tss_internal->ts[i]);
	273
	274	put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_OLD, sizeof(tss), &tss);
	275	}
	276	EXPORT_SYMBOL(put_cmsg_scm_timestamping);
	277
1da177e4 LT	278	void scm_detach_fds(struct msghdr msg, struct scm_cookie scm)
1da177e4 LT	279	{
cfcabdcc SH	280	struct cmsghdr __user *cm
cfcabdcc SH	281	= (__force struct cmsghdr __user*)msg->msg_control;
1da177e4 LT	282
	283	int fdmax = 0;
	284	int fdnum = scm->fp->count;
	285	struct file **fp = scm->fp->fp;
	286	int __user *cmfptr;
	287	int err = 0, i;
	288
	289	if (MSG_CMSG_COMPAT & msg->msg_flags) {
	290	scm_detach_fds_compat(msg, scm);
	291	return;
	292	}
	293
	294	if (msg->msg_controllen > sizeof(struct cmsghdr))
	295	fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr))
	296	/ sizeof(int));
	297
	298	if (fdnum < fdmax)
	299	fdmax = fdnum;
	300
cfcabdcc SH	301	for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
cfcabdcc SH	302	i++, cmfptr++)
1da177e4	303	{
48a87cc2	304	struct socket *sock;
1da177e4 LT	305	int new_fd;
	306	err = security_file_receive(fp[i]);
	307	if (err)
	308	break;
4a19542e UD	309	err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & msg->msg_flags
4a19542e UD	310	? O_CLOEXEC : 0);
1da177e4 LT	311	if (err < 0)
	312	break;
	313	new_fd = err;
	314	err = put_user(new_fd, cmfptr);
	315	if (err) {
	316	put_unused_fd(new_fd);
	317	break;
	318	}
	319	/* Bump the usage count and install the file. */
48a87cc2	320	sock = sock_from_file(fp[i], &err);
d8429506	321	if (sock) {
2a56a1fe TH	322	sock_update_netprioidx(&sock->sk->sk_cgrp_data);
2a56a1fe TH	323	sock_update_classid(&sock->sk->sk_cgrp_data);
d8429506	324	}
cb0942b8	325	fd_install(new_fd, get_file(fp[i]));
1da177e4 LT	326	}
	327
	328	if (i > 0)
	329	{
	330	int cmlen = CMSG_LEN(i*sizeof(int));
effee6a0	331	err = put_user(SOL_SOCKET, &cm->cmsg_level);
1da177e4 LT	332	if (!err)
	333	err = put_user(SCM_RIGHTS, &cm->cmsg_type);
	334	if (!err)
	335	err = put_user(cmlen, &cm->cmsg_len);
	336	if (!err) {
	337	cmlen = CMSG_SPACE(i*sizeof(int));
6900317f DB	338	if (msg->msg_controllen < cmlen)
6900317f DB	339	cmlen = msg->msg_controllen;
1da177e4 LT	340	msg->msg_control += cmlen;
	341	msg->msg_controllen -= cmlen;
	342	}
	343	}
	344	if (i < fdnum \|\| (fdnum && fdmax <= 0))
	345	msg->msg_flags \|= MSG_CTRUNC;
	346
	347	/*
	348	* All of the files that fit in the message have had their
	349	* usage counts incremented, so we just free the list.
	350	*/
	351	__scm_destroy(scm);
	352	}
9e34a5b5	353	EXPORT_SYMBOL(scm_detach_fds);
1da177e4 LT	354
	355	struct scm_fp_list scm_fp_dup(struct scm_fp_list fpl)
	356	{
	357	struct scm_fp_list *new_fpl;
	358	int i;
	359
	360	if (!fpl)
	361	return NULL;
	362
bba14de9 ED	363	new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]),
bba14de9 ED	364	GFP_KERNEL);
1da177e4	365	if (new_fpl) {
bba14de9	366	for (i = 0; i < fpl->count; i++)
1da177e4	367	get_file(fpl->fp[i]);
bba14de9	368	new_fpl->max = new_fpl->count;
415e3d3e	369	new_fpl->user = get_uid(fpl->user);
1da177e4 LT	370	}
	371	return new_fpl;
	372	}
1da177e4	373	EXPORT_SYMBOL(scm_fp_dup);