xref: /linux/net/compat.c (revision d198b34f3855eee2571dda03eea75a09c7c31480)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * 32bit Socket syscall emulation. Based on arch/sparc64/kernel/sys_sparc32.c.
4  *
5  * Copyright (C) 2000		VA Linux Co
6  * Copyright (C) 2000		Don Dugger <n0ano@valinux.com>
7  * Copyright (C) 1999 		Arun Sharma <arun.sharma@intel.com>
8  * Copyright (C) 1997,1998 	Jakub Jelinek (jj@sunsite.mff.cuni.cz)
9  * Copyright (C) 1997 		David S. Miller (davem@caip.rutgers.edu)
10  * Copyright (C) 2000		Hewlett-Packard Co.
11  * Copyright (C) 2000		David Mosberger-Tang <davidm@hpl.hp.com>
12  * Copyright (C) 2000,2001	Andi Kleen, SuSE Labs
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/gfp.h>
17 #include <linux/fs.h>
18 #include <linux/types.h>
19 #include <linux/file.h>
20 #include <linux/icmpv6.h>
21 #include <linux/socket.h>
22 #include <linux/syscalls.h>
23 #include <linux/filter.h>
24 #include <linux/compat.h>
25 #include <linux/security.h>
26 #include <linux/audit.h>
27 #include <linux/export.h>
28 
29 #include <net/scm.h>
30 #include <net/sock.h>
31 #include <net/ip.h>
32 #include <net/ipv6.h>
33 #include <linux/uaccess.h>
34 #include <net/compat.h>
35 
36 int get_compat_msghdr(struct msghdr *kmsg,
37 		      struct compat_msghdr __user *umsg,
38 		      struct sockaddr __user **save_addr,
39 		      struct iovec **iov)
40 {
41 	struct compat_msghdr msg;
42 	ssize_t err;
43 
44 	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
45 		return -EFAULT;
46 
47 	kmsg->msg_flags = msg.msg_flags;
48 	kmsg->msg_namelen = msg.msg_namelen;
49 
50 	if (!msg.msg_name)
51 		kmsg->msg_namelen = 0;
52 
53 	if (kmsg->msg_namelen < 0)
54 		return -EINVAL;
55 
56 	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
57 		kmsg->msg_namelen = sizeof(struct sockaddr_storage);
58 
59 	kmsg->msg_control = compat_ptr(msg.msg_control);
60 	kmsg->msg_controllen = msg.msg_controllen;
61 
62 	if (save_addr)
63 		*save_addr = compat_ptr(msg.msg_name);
64 
65 	if (msg.msg_name && kmsg->msg_namelen) {
66 		if (!save_addr) {
67 			err = move_addr_to_kernel(compat_ptr(msg.msg_name),
68 						  kmsg->msg_namelen,
69 						  kmsg->msg_name);
70 			if (err < 0)
71 				return err;
72 		}
73 	} else {
74 		kmsg->msg_name = NULL;
75 		kmsg->msg_namelen = 0;
76 	}
77 
78 	if (msg.msg_iovlen > UIO_MAXIOV)
79 		return -EMSGSIZE;
80 
81 	kmsg->msg_iocb = NULL;
82 
83 	err = compat_import_iovec(save_addr ? READ : WRITE,
84 				   compat_ptr(msg.msg_iov), msg.msg_iovlen,
85 				   UIO_FASTIOV, iov, &kmsg->msg_iter);
86 	return err < 0 ? err : 0;
87 }
88 
89 /* Bleech... */
90 #define CMSG_COMPAT_ALIGN(len)	ALIGN((len), sizeof(s32))
91 
92 #define CMSG_COMPAT_DATA(cmsg)				\
93 	((void __user *)((char __user *)(cmsg) + sizeof(struct compat_cmsghdr)))
94 #define CMSG_COMPAT_SPACE(len)				\
95 	(sizeof(struct compat_cmsghdr) + CMSG_COMPAT_ALIGN(len))
96 #define CMSG_COMPAT_LEN(len)				\
97 	(sizeof(struct compat_cmsghdr) + (len))
98 
99 #define CMSG_COMPAT_FIRSTHDR(msg)			\
100 	(((msg)->msg_controllen) >= sizeof(struct compat_cmsghdr) ?	\
101 	 (struct compat_cmsghdr __user *)((msg)->msg_control) :		\
102 	 (struct compat_cmsghdr __user *)NULL)
103 
104 #define CMSG_COMPAT_OK(ucmlen, ucmsg, mhdr) \
105 	((ucmlen) >= sizeof(struct compat_cmsghdr) && \
106 	 (ucmlen) <= (unsigned long) \
107 	 ((mhdr)->msg_controllen - \
108 	  ((char *)(ucmsg) - (char *)(mhdr)->msg_control)))
109 
110 static inline struct compat_cmsghdr __user *cmsg_compat_nxthdr(struct msghdr *msg,
111 		struct compat_cmsghdr __user *cmsg, int cmsg_len)
112 {
113 	char __user *ptr = (char __user *)cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
114 	if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control) >
115 			msg->msg_controllen)
116 		return NULL;
117 	return (struct compat_cmsghdr __user *)ptr;
118 }
119 
120 /* There is a lot of hair here because the alignment rules (and
121  * thus placement) of cmsg headers and length are different for
122  * 32-bit apps.  -DaveM
123  */
124 int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg, struct sock *sk,
125 			       unsigned char *stackbuf, int stackbuf_size)
126 {
127 	struct compat_cmsghdr __user *ucmsg;
128 	struct cmsghdr *kcmsg, *kcmsg_base;
129 	compat_size_t ucmlen;
130 	__kernel_size_t kcmlen, tmp;
131 	int err = -EFAULT;
132 
133 	BUILD_BUG_ON(sizeof(struct compat_cmsghdr) !=
134 		     CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)));
135 
136 	kcmlen = 0;
137 	kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf;
138 	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
139 	while (ucmsg != NULL) {
140 		if (get_user(ucmlen, &ucmsg->cmsg_len))
141 			return -EFAULT;
142 
143 		/* Catch bogons. */
144 		if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
145 			return -EINVAL;
146 
147 		tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
148 		tmp = CMSG_ALIGN(tmp);
149 		kcmlen += tmp;
150 		ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
151 	}
152 	if (kcmlen == 0)
153 		return -EINVAL;
154 
155 	/* The kcmlen holds the 64-bit version of the control length.
156 	 * It may not be modified as we do not stick it into the kmsg
157 	 * until we have successfully copied over all of the data
158 	 * from the user.
159 	 */
160 	if (kcmlen > stackbuf_size)
161 		kcmsg_base = kcmsg = sock_kmalloc(sk, kcmlen, GFP_KERNEL);
162 	if (kcmsg == NULL)
163 		return -ENOBUFS;
164 
165 	/* Now copy them over neatly. */
166 	memset(kcmsg, 0, kcmlen);
167 	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
168 	while (ucmsg != NULL) {
169 		if (__get_user(ucmlen, &ucmsg->cmsg_len))
170 			goto Efault;
171 		if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
172 			goto Einval;
173 		tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
174 		if ((char *)kcmsg_base + kcmlen - (char *)kcmsg < CMSG_ALIGN(tmp))
175 			goto Einval;
176 		kcmsg->cmsg_len = tmp;
177 		tmp = CMSG_ALIGN(tmp);
178 		if (__get_user(kcmsg->cmsg_level, &ucmsg->cmsg_level) ||
179 		    __get_user(kcmsg->cmsg_type, &ucmsg->cmsg_type) ||
180 		    copy_from_user(CMSG_DATA(kcmsg),
181 				   CMSG_COMPAT_DATA(ucmsg),
182 				   (ucmlen - sizeof(*ucmsg))))
183 			goto Efault;
184 
185 		/* Advance. */
186 		kcmsg = (struct cmsghdr *)((char *)kcmsg + tmp);
187 		ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
188 	}
189 
190 	/*
191 	 * check the length of messages copied in is the same as the
192 	 * what we get from the first loop
193 	 */
194 	if ((char *)kcmsg - (char *)kcmsg_base != kcmlen)
195 		goto Einval;
196 
197 	/* Ok, looks like we made it.  Hook it up and return success. */
198 	kmsg->msg_control = kcmsg_base;
199 	kmsg->msg_controllen = kcmlen;
200 	return 0;
201 
202 Einval:
203 	err = -EINVAL;
204 Efault:
205 	if (kcmsg_base != (struct cmsghdr *)stackbuf)
206 		sock_kfree_s(sk, kcmsg_base, kcmlen);
207 	return err;
208 }
209 
210 int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *data)
211 {
212 	struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
213 	struct compat_cmsghdr cmhdr;
214 	struct old_timeval32 ctv;
215 	struct old_timespec32 cts[3];
216 	int cmlen;
217 
218 	if (cm == NULL || kmsg->msg_controllen < sizeof(*cm)) {
219 		kmsg->msg_flags |= MSG_CTRUNC;
220 		return 0; /* XXX: return error? check spec. */
221 	}
222 
223 	if (!COMPAT_USE_64BIT_TIME) {
224 		if (level == SOL_SOCKET && type == SO_TIMESTAMP_OLD) {
225 			struct __kernel_old_timeval *tv = (struct __kernel_old_timeval *)data;
226 			ctv.tv_sec = tv->tv_sec;
227 			ctv.tv_usec = tv->tv_usec;
228 			data = &ctv;
229 			len = sizeof(ctv);
230 		}
231 		if (level == SOL_SOCKET &&
232 		    (type == SO_TIMESTAMPNS_OLD || type == SO_TIMESTAMPING_OLD)) {
233 			int count = type == SO_TIMESTAMPNS_OLD ? 1 : 3;
234 			int i;
235 			struct __kernel_old_timespec *ts = data;
236 			for (i = 0; i < count; i++) {
237 				cts[i].tv_sec = ts[i].tv_sec;
238 				cts[i].tv_nsec = ts[i].tv_nsec;
239 			}
240 			data = &cts;
241 			len = sizeof(cts[0]) * count;
242 		}
243 	}
244 
245 	cmlen = CMSG_COMPAT_LEN(len);
246 	if (kmsg->msg_controllen < cmlen) {
247 		kmsg->msg_flags |= MSG_CTRUNC;
248 		cmlen = kmsg->msg_controllen;
249 	}
250 	cmhdr.cmsg_level = level;
251 	cmhdr.cmsg_type = type;
252 	cmhdr.cmsg_len = cmlen;
253 
254 	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
255 		return -EFAULT;
256 	if (copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr)))
257 		return -EFAULT;
258 	cmlen = CMSG_COMPAT_SPACE(len);
259 	if (kmsg->msg_controllen < cmlen)
260 		cmlen = kmsg->msg_controllen;
261 	kmsg->msg_control += cmlen;
262 	kmsg->msg_controllen -= cmlen;
263 	return 0;
264 }
265 
266 void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
267 {
268 	struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
269 	int fdmax = (kmsg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
270 	int fdnum = scm->fp->count;
271 	struct file **fp = scm->fp->fp;
272 	int __user *cmfptr;
273 	int err = 0, i;
274 
275 	if (fdnum < fdmax)
276 		fdmax = fdnum;
277 
278 	for (i = 0, cmfptr = (int __user *) CMSG_COMPAT_DATA(cm); i < fdmax; i++, cmfptr++) {
279 		int new_fd;
280 		err = security_file_receive(fp[i]);
281 		if (err)
282 			break;
283 		err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & kmsg->msg_flags
284 					  ? O_CLOEXEC : 0);
285 		if (err < 0)
286 			break;
287 		new_fd = err;
288 		err = put_user(new_fd, cmfptr);
289 		if (err) {
290 			put_unused_fd(new_fd);
291 			break;
292 		}
293 		/* Bump the usage count and install the file. */
294 		fd_install(new_fd, get_file(fp[i]));
295 	}
296 
297 	if (i > 0) {
298 		int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
299 		err = put_user(SOL_SOCKET, &cm->cmsg_level);
300 		if (!err)
301 			err = put_user(SCM_RIGHTS, &cm->cmsg_type);
302 		if (!err)
303 			err = put_user(cmlen, &cm->cmsg_len);
304 		if (!err) {
305 			cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
306 			kmsg->msg_control += cmlen;
307 			kmsg->msg_controllen -= cmlen;
308 		}
309 	}
310 	if (i < fdnum)
311 		kmsg->msg_flags |= MSG_CTRUNC;
312 
313 	/*
314 	 * All of the files that fit in the message have had their
315 	 * usage counts incremented, so we just free the list.
316 	 */
317 	__scm_destroy(scm);
318 }
319 
320 /* allocate a 64-bit sock_fprog on the user stack for duration of syscall. */
321 struct sock_fprog __user *get_compat_bpf_fprog(char __user *optval)
322 {
323 	struct compat_sock_fprog __user *fprog32 = (struct compat_sock_fprog __user *)optval;
324 	struct sock_fprog __user *kfprog = compat_alloc_user_space(sizeof(struct sock_fprog));
325 	struct compat_sock_fprog f32;
326 	struct sock_fprog f;
327 
328 	if (copy_from_user(&f32, fprog32, sizeof(*fprog32)))
329 		return NULL;
330 	memset(&f, 0, sizeof(f));
331 	f.len = f32.len;
332 	f.filter = compat_ptr(f32.filter);
333 	if (copy_to_user(kfprog, &f, sizeof(struct sock_fprog)))
334 		return NULL;
335 
336 	return kfprog;
337 }
338 EXPORT_SYMBOL_GPL(get_compat_bpf_fprog);
339 
340 static int do_set_attach_filter(struct socket *sock, int level, int optname,
341 				char __user *optval, unsigned int optlen)
342 {
343 	struct sock_fprog __user *kfprog;
344 
345 	kfprog = get_compat_bpf_fprog(optval);
346 	if (!kfprog)
347 		return -EFAULT;
348 
349 	return sock_setsockopt(sock, level, optname, (char __user *)kfprog,
350 			      sizeof(struct sock_fprog));
351 }
352 
353 static int compat_sock_setsockopt(struct socket *sock, int level, int optname,
354 				char __user *optval, unsigned int optlen)
355 {
356 	if (optname == SO_ATTACH_FILTER ||
357 	    optname == SO_ATTACH_REUSEPORT_CBPF)
358 		return do_set_attach_filter(sock, level, optname,
359 					    optval, optlen);
360 	return sock_setsockopt(sock, level, optname, optval, optlen);
361 }
362 
363 static int __compat_sys_setsockopt(int fd, int level, int optname,
364 				   char __user *optval, unsigned int optlen)
365 {
366 	int err;
367 	struct socket *sock;
368 
369 	if (optlen > INT_MAX)
370 		return -EINVAL;
371 
372 	sock = sockfd_lookup(fd, &err);
373 	if (sock) {
374 		err = security_socket_setsockopt(sock, level, optname);
375 		if (err) {
376 			sockfd_put(sock);
377 			return err;
378 		}
379 
380 		if (level == SOL_SOCKET)
381 			err = compat_sock_setsockopt(sock, level,
382 					optname, optval, optlen);
383 		else if (sock->ops->compat_setsockopt)
384 			err = sock->ops->compat_setsockopt(sock, level,
385 					optname, optval, optlen);
386 		else
387 			err = sock->ops->setsockopt(sock, level,
388 					optname, optval, optlen);
389 		sockfd_put(sock);
390 	}
391 	return err;
392 }
393 
394 COMPAT_SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
395 		       char __user *, optval, unsigned int, optlen)
396 {
397 	return __compat_sys_setsockopt(fd, level, optname, optval, optlen);
398 }
399 
400 static int __compat_sys_getsockopt(int fd, int level, int optname,
401 				   char __user *optval,
402 				   int __user *optlen)
403 {
404 	int err;
405 	struct socket *sock = sockfd_lookup(fd, &err);
406 
407 	if (sock) {
408 		err = security_socket_getsockopt(sock, level, optname);
409 		if (err) {
410 			sockfd_put(sock);
411 			return err;
412 		}
413 
414 		if (level == SOL_SOCKET)
415 			err = sock_getsockopt(sock, level,
416 					optname, optval, optlen);
417 		else if (sock->ops->compat_getsockopt)
418 			err = sock->ops->compat_getsockopt(sock, level,
419 					optname, optval, optlen);
420 		else
421 			err = sock->ops->getsockopt(sock, level,
422 					optname, optval, optlen);
423 		sockfd_put(sock);
424 	}
425 	return err;
426 }
427 
428 COMPAT_SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
429 		       char __user *, optval, int __user *, optlen)
430 {
431 	return __compat_sys_getsockopt(fd, level, optname, optval, optlen);
432 }
433 
434 struct compat_group_req {
435 	__u32				 gr_interface;
436 	struct __kernel_sockaddr_storage gr_group
437 		__aligned(4);
438 } __packed;
439 
440 struct compat_group_source_req {
441 	__u32				 gsr_interface;
442 	struct __kernel_sockaddr_storage gsr_group
443 		__aligned(4);
444 	struct __kernel_sockaddr_storage gsr_source
445 		__aligned(4);
446 } __packed;
447 
448 struct compat_group_filter {
449 	__u32				 gf_interface;
450 	struct __kernel_sockaddr_storage gf_group
451 		__aligned(4);
452 	__u32				 gf_fmode;
453 	__u32				 gf_numsrc;
454 	struct __kernel_sockaddr_storage gf_slist[1]
455 		__aligned(4);
456 } __packed;
457 
458 #define __COMPAT_GF0_SIZE (sizeof(struct compat_group_filter) - \
459 			sizeof(struct __kernel_sockaddr_storage))
460 
461 
462 int compat_mc_setsockopt(struct sock *sock, int level, int optname,
463 	char __user *optval, unsigned int optlen,
464 	int (*setsockopt)(struct sock *, int, int, char __user *, unsigned int))
465 {
466 	char __user	*koptval = optval;
467 	int		koptlen = optlen;
468 
469 	switch (optname) {
470 	case MCAST_JOIN_GROUP:
471 	case MCAST_LEAVE_GROUP:
472 	{
473 		struct compat_group_req __user *gr32 = (void __user *)optval;
474 		struct group_req __user *kgr =
475 			compat_alloc_user_space(sizeof(struct group_req));
476 		u32 interface;
477 
478 		if (!access_ok(gr32, sizeof(*gr32)) ||
479 		    !access_ok(kgr, sizeof(struct group_req)) ||
480 		    __get_user(interface, &gr32->gr_interface) ||
481 		    __put_user(interface, &kgr->gr_interface) ||
482 		    copy_in_user(&kgr->gr_group, &gr32->gr_group,
483 				sizeof(kgr->gr_group)))
484 			return -EFAULT;
485 		koptval = (char __user *)kgr;
486 		koptlen = sizeof(struct group_req);
487 		break;
488 	}
489 	case MCAST_JOIN_SOURCE_GROUP:
490 	case MCAST_LEAVE_SOURCE_GROUP:
491 	case MCAST_BLOCK_SOURCE:
492 	case MCAST_UNBLOCK_SOURCE:
493 	{
494 		struct compat_group_source_req __user *gsr32 = (void __user *)optval;
495 		struct group_source_req __user *kgsr = compat_alloc_user_space(
496 			sizeof(struct group_source_req));
497 		u32 interface;
498 
499 		if (!access_ok(gsr32, sizeof(*gsr32)) ||
500 		    !access_ok(kgsr,
501 			sizeof(struct group_source_req)) ||
502 		    __get_user(interface, &gsr32->gsr_interface) ||
503 		    __put_user(interface, &kgsr->gsr_interface) ||
504 		    copy_in_user(&kgsr->gsr_group, &gsr32->gsr_group,
505 				sizeof(kgsr->gsr_group)) ||
506 		    copy_in_user(&kgsr->gsr_source, &gsr32->gsr_source,
507 				sizeof(kgsr->gsr_source)))
508 			return -EFAULT;
509 		koptval = (char __user *)kgsr;
510 		koptlen = sizeof(struct group_source_req);
511 		break;
512 	}
513 	case MCAST_MSFILTER:
514 	{
515 		struct compat_group_filter __user *gf32 = (void __user *)optval;
516 		struct group_filter __user *kgf;
517 		u32 interface, fmode, numsrc;
518 
519 		if (!access_ok(gf32, __COMPAT_GF0_SIZE) ||
520 		    __get_user(interface, &gf32->gf_interface) ||
521 		    __get_user(fmode, &gf32->gf_fmode) ||
522 		    __get_user(numsrc, &gf32->gf_numsrc))
523 			return -EFAULT;
524 		koptlen = optlen + sizeof(struct group_filter) -
525 				sizeof(struct compat_group_filter);
526 		if (koptlen < GROUP_FILTER_SIZE(numsrc))
527 			return -EINVAL;
528 		kgf = compat_alloc_user_space(koptlen);
529 		if (!access_ok(kgf, koptlen) ||
530 		    __put_user(interface, &kgf->gf_interface) ||
531 		    __put_user(fmode, &kgf->gf_fmode) ||
532 		    __put_user(numsrc, &kgf->gf_numsrc) ||
533 		    copy_in_user(&kgf->gf_group, &gf32->gf_group,
534 				sizeof(kgf->gf_group)) ||
535 		    (numsrc && copy_in_user(kgf->gf_slist, gf32->gf_slist,
536 				numsrc * sizeof(kgf->gf_slist[0]))))
537 			return -EFAULT;
538 		koptval = (char __user *)kgf;
539 		break;
540 	}
541 
542 	default:
543 		break;
544 	}
545 	return setsockopt(sock, level, optname, koptval, koptlen);
546 }
547 EXPORT_SYMBOL(compat_mc_setsockopt);
548 
549 int compat_mc_getsockopt(struct sock *sock, int level, int optname,
550 	char __user *optval, int __user *optlen,
551 	int (*getsockopt)(struct sock *, int, int, char __user *, int __user *))
552 {
553 	struct compat_group_filter __user *gf32 = (void __user *)optval;
554 	struct group_filter __user *kgf;
555 	int __user	*koptlen;
556 	u32 interface, fmode, numsrc;
557 	int klen, ulen, err;
558 
559 	if (optname != MCAST_MSFILTER)
560 		return getsockopt(sock, level, optname, optval, optlen);
561 
562 	koptlen = compat_alloc_user_space(sizeof(*koptlen));
563 	if (!access_ok(optlen, sizeof(*optlen)) ||
564 	    __get_user(ulen, optlen))
565 		return -EFAULT;
566 
567 	/* adjust len for pad */
568 	klen = ulen + sizeof(*kgf) - sizeof(*gf32);
569 
570 	if (klen < GROUP_FILTER_SIZE(0))
571 		return -EINVAL;
572 
573 	if (!access_ok(koptlen, sizeof(*koptlen)) ||
574 	    __put_user(klen, koptlen))
575 		return -EFAULT;
576 
577 	/* have to allow space for previous compat_alloc_user_space, too */
578 	kgf = compat_alloc_user_space(klen+sizeof(*optlen));
579 
580 	if (!access_ok(gf32, __COMPAT_GF0_SIZE) ||
581 	    __get_user(interface, &gf32->gf_interface) ||
582 	    __get_user(fmode, &gf32->gf_fmode) ||
583 	    __get_user(numsrc, &gf32->gf_numsrc) ||
584 	    __put_user(interface, &kgf->gf_interface) ||
585 	    __put_user(fmode, &kgf->gf_fmode) ||
586 	    __put_user(numsrc, &kgf->gf_numsrc) ||
587 	    copy_in_user(&kgf->gf_group, &gf32->gf_group, sizeof(kgf->gf_group)))
588 		return -EFAULT;
589 
590 	err = getsockopt(sock, level, optname, (char __user *)kgf, koptlen);
591 	if (err)
592 		return err;
593 
594 	if (!access_ok(koptlen, sizeof(*koptlen)) ||
595 	    __get_user(klen, koptlen))
596 		return -EFAULT;
597 
598 	ulen = klen - (sizeof(*kgf)-sizeof(*gf32));
599 
600 	if (!access_ok(optlen, sizeof(*optlen)) ||
601 	    __put_user(ulen, optlen))
602 		return -EFAULT;
603 
604 	if (!access_ok(kgf, klen) ||
605 	    !access_ok(gf32, ulen) ||
606 	    __get_user(interface, &kgf->gf_interface) ||
607 	    __get_user(fmode, &kgf->gf_fmode) ||
608 	    __get_user(numsrc, &kgf->gf_numsrc) ||
609 	    __put_user(interface, &gf32->gf_interface) ||
610 	    __put_user(fmode, &gf32->gf_fmode) ||
611 	    __put_user(numsrc, &gf32->gf_numsrc))
612 		return -EFAULT;
613 	if (numsrc) {
614 		int copylen;
615 
616 		klen -= GROUP_FILTER_SIZE(0);
617 		copylen = numsrc * sizeof(gf32->gf_slist[0]);
618 		if (copylen > klen)
619 			copylen = klen;
620 		if (copy_in_user(gf32->gf_slist, kgf->gf_slist, copylen))
621 			return -EFAULT;
622 	}
623 	return err;
624 }
625 EXPORT_SYMBOL(compat_mc_getsockopt);
626 
627 
628 /* Argument list sizes for compat_sys_socketcall */
629 #define AL(x) ((x) * sizeof(u32))
630 static unsigned char nas[21] = {
631 	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
632 	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
633 	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
634 	AL(4), AL(5), AL(4)
635 };
636 #undef AL
637 
638 static inline long __compat_sys_sendmsg(int fd,
639 					struct compat_msghdr __user *msg,
640 					unsigned int flags)
641 {
642 	return __sys_sendmsg(fd, (struct user_msghdr __user *)msg,
643 			     flags | MSG_CMSG_COMPAT, false);
644 }
645 
646 COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg,
647 		       unsigned int, flags)
648 {
649 	return __compat_sys_sendmsg(fd, msg, flags);
650 }
651 
652 static inline long __compat_sys_sendmmsg(int fd,
653 					 struct compat_mmsghdr __user *mmsg,
654 					 unsigned int vlen, unsigned int flags)
655 {
656 	return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
657 			      flags | MSG_CMSG_COMPAT, false);
658 }
659 
660 COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
661 		       unsigned int, vlen, unsigned int, flags)
662 {
663 	return __compat_sys_sendmmsg(fd, mmsg, vlen, flags);
664 }
665 
666 static inline long __compat_sys_recvmsg(int fd,
667 					struct compat_msghdr __user *msg,
668 					unsigned int flags)
669 {
670 	return __sys_recvmsg(fd, (struct user_msghdr __user *)msg,
671 			     flags | MSG_CMSG_COMPAT, false);
672 }
673 
674 COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg,
675 		       unsigned int, flags)
676 {
677 	return __compat_sys_recvmsg(fd, msg, flags);
678 }
679 
680 static inline long __compat_sys_recvfrom(int fd, void __user *buf,
681 					 compat_size_t len, unsigned int flags,
682 					 struct sockaddr __user *addr,
683 					 int __user *addrlen)
684 {
685 	return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr,
686 			      addrlen);
687 }
688 
689 COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)
690 {
691 	return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL);
692 }
693 
694 COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len,
695 		       unsigned int, flags, struct sockaddr __user *, addr,
696 		       int __user *, addrlen)
697 {
698 	return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
699 }
700 
701 COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg,
702 		       unsigned int, vlen, unsigned int, flags,
703 		       struct __kernel_timespec __user *, timeout)
704 {
705 	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
706 			      flags | MSG_CMSG_COMPAT, timeout, NULL);
707 }
708 
709 #ifdef CONFIG_COMPAT_32BIT_TIME
710 COMPAT_SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct compat_mmsghdr __user *, mmsg,
711 		       unsigned int, vlen, unsigned int, flags,
712 		       struct old_timespec32 __user *, timeout)
713 {
714 	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
715 			      flags | MSG_CMSG_COMPAT, NULL, timeout);
716 }
717 #endif
718 
719 COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
720 {
721 	u32 a[AUDITSC_ARGS];
722 	unsigned int len;
723 	u32 a0, a1;
724 	int ret;
725 
726 	if (call < SYS_SOCKET || call > SYS_SENDMMSG)
727 		return -EINVAL;
728 	len = nas[call];
729 	if (len > sizeof(a))
730 		return -EINVAL;
731 
732 	if (copy_from_user(a, args, len))
733 		return -EFAULT;
734 
735 	ret = audit_socketcall_compat(len / sizeof(a[0]), a);
736 	if (ret)
737 		return ret;
738 
739 	a0 = a[0];
740 	a1 = a[1];
741 
742 	switch (call) {
743 	case SYS_SOCKET:
744 		ret = __sys_socket(a0, a1, a[2]);
745 		break;
746 	case SYS_BIND:
747 		ret = __sys_bind(a0, compat_ptr(a1), a[2]);
748 		break;
749 	case SYS_CONNECT:
750 		ret = __sys_connect(a0, compat_ptr(a1), a[2]);
751 		break;
752 	case SYS_LISTEN:
753 		ret = __sys_listen(a0, a1);
754 		break;
755 	case SYS_ACCEPT:
756 		ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
757 		break;
758 	case SYS_GETSOCKNAME:
759 		ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
760 		break;
761 	case SYS_GETPEERNAME:
762 		ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
763 		break;
764 	case SYS_SOCKETPAIR:
765 		ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
766 		break;
767 	case SYS_SEND:
768 		ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3], NULL, 0);
769 		break;
770 	case SYS_SENDTO:
771 		ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3],
772 				   compat_ptr(a[4]), a[5]);
773 		break;
774 	case SYS_RECV:
775 		ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
776 					    NULL, NULL);
777 		break;
778 	case SYS_RECVFROM:
779 		ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
780 					    compat_ptr(a[4]),
781 					    compat_ptr(a[5]));
782 		break;
783 	case SYS_SHUTDOWN:
784 		ret = __sys_shutdown(a0, a1);
785 		break;
786 	case SYS_SETSOCKOPT:
787 		ret = __compat_sys_setsockopt(a0, a1, a[2],
788 					      compat_ptr(a[3]), a[4]);
789 		break;
790 	case SYS_GETSOCKOPT:
791 		ret = __compat_sys_getsockopt(a0, a1, a[2],
792 					      compat_ptr(a[3]),
793 					      compat_ptr(a[4]));
794 		break;
795 	case SYS_SENDMSG:
796 		ret = __compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
797 		break;
798 	case SYS_SENDMMSG:
799 		ret = __compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
800 		break;
801 	case SYS_RECVMSG:
802 		ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
803 		break;
804 	case SYS_RECVMMSG:
805 		ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2],
806 				     a[3] | MSG_CMSG_COMPAT, NULL,
807 				     compat_ptr(a[4]));
808 		break;
809 	case SYS_ACCEPT4:
810 		ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
811 		break;
812 	default:
813 		ret = -EINVAL;
814 		break;
815 	}
816 	return ret;
817 }
818