compat.c 14 KB

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  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. #include <linux/kernel.h>
  15. #include <linux/gfp.h>
  16. #include <linux/fs.h>
  17. #include <linux/types.h>
  18. #include <linux/file.h>
  19. #include <linux/icmpv6.h>
  20. #include <linux/socket.h>
  21. #include <linux/syscalls.h>
  22. #include <linux/filter.h>
  23. #include <linux/compat.h>
  24. #include <linux/security.h>
  25. #include <linux/audit.h>
  26. #include <linux/export.h>
  27. #include <net/scm.h>
  28. #include <net/sock.h>
  29. #include <net/ip.h>
  30. #include <net/ipv6.h>
  31. #include <linux/uaccess.h>
  32. #include <net/compat.h>
  33. int __get_compat_msghdr(struct msghdr *kmsg,
  34. struct compat_msghdr __user *umsg,
  35. struct sockaddr __user **save_addr,
  36. compat_uptr_t *ptr, compat_size_t *len)
  37. {
  38. struct compat_msghdr msg;
  39. ssize_t err;
  40. if (copy_from_user(&msg, umsg, sizeof(*umsg)))
  41. return -EFAULT;
  42. kmsg->msg_flags = msg.msg_flags;
  43. kmsg->msg_namelen = msg.msg_namelen;
  44. if (!msg.msg_name)
  45. kmsg->msg_namelen = 0;
  46. if (kmsg->msg_namelen < 0)
  47. return -EINVAL;
  48. if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
  49. kmsg->msg_namelen = sizeof(struct sockaddr_storage);
  50. kmsg->msg_control_is_user = true;
  51. kmsg->msg_control_user = compat_ptr(msg.msg_control);
  52. kmsg->msg_controllen = msg.msg_controllen;
  53. if (save_addr)
  54. *save_addr = compat_ptr(msg.msg_name);
  55. if (msg.msg_name && kmsg->msg_namelen) {
  56. if (!save_addr) {
  57. err = move_addr_to_kernel(compat_ptr(msg.msg_name),
  58. kmsg->msg_namelen,
  59. kmsg->msg_name);
  60. if (err < 0)
  61. return err;
  62. }
  63. } else {
  64. kmsg->msg_name = NULL;
  65. kmsg->msg_namelen = 0;
  66. }
  67. if (msg.msg_iovlen > UIO_MAXIOV)
  68. return -EMSGSIZE;
  69. kmsg->msg_iocb = NULL;
  70. *ptr = msg.msg_iov;
  71. *len = msg.msg_iovlen;
  72. return 0;
  73. }
  74. int get_compat_msghdr(struct msghdr *kmsg,
  75. struct compat_msghdr __user *umsg,
  76. struct sockaddr __user **save_addr,
  77. struct iovec **iov)
  78. {
  79. compat_uptr_t ptr;
  80. compat_size_t len;
  81. ssize_t err;
  82. err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len);
  83. if (err)
  84. return err;
  85. err = import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), len,
  86. UIO_FASTIOV, iov, &kmsg->msg_iter);
  87. return err < 0 ? err : 0;
  88. }
  89. /* Bleech... */
  90. #define CMSG_COMPAT_ALIGN(len) ALIGN((len), sizeof(s32))
  91. #define CMSG_COMPAT_DATA(cmsg) \
  92. ((void __user *)((char __user *)(cmsg) + sizeof(struct compat_cmsghdr)))
  93. #define CMSG_COMPAT_SPACE(len) \
  94. (sizeof(struct compat_cmsghdr) + CMSG_COMPAT_ALIGN(len))
  95. #define CMSG_COMPAT_LEN(len) \
  96. (sizeof(struct compat_cmsghdr) + (len))
  97. #define CMSG_COMPAT_FIRSTHDR(msg) \
  98. (((msg)->msg_controllen) >= sizeof(struct compat_cmsghdr) ? \
  99. (struct compat_cmsghdr __user *)((msg)->msg_control) : \
  100. (struct compat_cmsghdr __user *)NULL)
  101. #define CMSG_COMPAT_OK(ucmlen, ucmsg, mhdr) \
  102. ((ucmlen) >= sizeof(struct compat_cmsghdr) && \
  103. (ucmlen) <= (unsigned long) \
  104. ((mhdr)->msg_controllen - \
  105. ((char __user *)(ucmsg) - (char __user *)(mhdr)->msg_control_user)))
  106. static inline struct compat_cmsghdr __user *cmsg_compat_nxthdr(struct msghdr *msg,
  107. struct compat_cmsghdr __user *cmsg, int cmsg_len)
  108. {
  109. char __user *ptr = (char __user *)cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
  110. if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control) >
  111. msg->msg_controllen)
  112. return NULL;
  113. return (struct compat_cmsghdr __user *)ptr;
  114. }
  115. /* There is a lot of hair here because the alignment rules (and
  116. * thus placement) of cmsg headers and length are different for
  117. * 32-bit apps. -DaveM
  118. */
  119. int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg, struct sock *sk,
  120. unsigned char *stackbuf, int stackbuf_size)
  121. {
  122. struct compat_cmsghdr __user *ucmsg;
  123. struct cmsghdr *kcmsg, *kcmsg_base;
  124. compat_size_t ucmlen;
  125. __kernel_size_t kcmlen, tmp;
  126. int err = -EFAULT;
  127. BUILD_BUG_ON(sizeof(struct compat_cmsghdr) !=
  128. CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)));
  129. kcmlen = 0;
  130. kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf;
  131. ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
  132. while (ucmsg != NULL) {
  133. if (get_user(ucmlen, &ucmsg->cmsg_len))
  134. return -EFAULT;
  135. /* Catch bogons. */
  136. if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
  137. return -EINVAL;
  138. tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
  139. tmp = CMSG_ALIGN(tmp);
  140. kcmlen += tmp;
  141. ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
  142. }
  143. if (kcmlen == 0)
  144. return -EINVAL;
  145. /* The kcmlen holds the 64-bit version of the control length.
  146. * It may not be modified as we do not stick it into the kmsg
  147. * until we have successfully copied over all of the data
  148. * from the user.
  149. */
  150. if (kcmlen > stackbuf_size)
  151. kcmsg_base = kcmsg = sock_kmalloc(sk, kcmlen, GFP_KERNEL);
  152. if (kcmsg == NULL)
  153. return -ENOMEM;
  154. /* Now copy them over neatly. */
  155. memset(kcmsg, 0, kcmlen);
  156. ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
  157. while (ucmsg != NULL) {
  158. struct compat_cmsghdr cmsg;
  159. if (copy_from_user(&cmsg, ucmsg, sizeof(cmsg)))
  160. goto Efault;
  161. if (!CMSG_COMPAT_OK(cmsg.cmsg_len, ucmsg, kmsg))
  162. goto Einval;
  163. tmp = ((cmsg.cmsg_len - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
  164. if ((char *)kcmsg_base + kcmlen - (char *)kcmsg < CMSG_ALIGN(tmp))
  165. goto Einval;
  166. kcmsg->cmsg_len = tmp;
  167. kcmsg->cmsg_level = cmsg.cmsg_level;
  168. kcmsg->cmsg_type = cmsg.cmsg_type;
  169. tmp = CMSG_ALIGN(tmp);
  170. if (copy_from_user(CMSG_DATA(kcmsg),
  171. CMSG_COMPAT_DATA(ucmsg),
  172. (cmsg.cmsg_len - sizeof(*ucmsg))))
  173. goto Efault;
  174. /* Advance. */
  175. kcmsg = (struct cmsghdr *)((char *)kcmsg + tmp);
  176. ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, cmsg.cmsg_len);
  177. }
  178. /*
  179. * check the length of messages copied in is the same as the
  180. * what we get from the first loop
  181. */
  182. if ((char *)kcmsg - (char *)kcmsg_base != kcmlen)
  183. goto Einval;
  184. /* Ok, looks like we made it. Hook it up and return success. */
  185. kmsg->msg_control = kcmsg_base;
  186. kmsg->msg_controllen = kcmlen;
  187. return 0;
  188. Einval:
  189. err = -EINVAL;
  190. Efault:
  191. if (kcmsg_base != (struct cmsghdr *)stackbuf)
  192. sock_kfree_s(sk, kcmsg_base, kcmlen);
  193. return err;
  194. }
  195. int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *data)
  196. {
  197. struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
  198. struct compat_cmsghdr cmhdr;
  199. struct old_timeval32 ctv;
  200. struct old_timespec32 cts[3];
  201. int cmlen;
  202. if (cm == NULL || kmsg->msg_controllen < sizeof(*cm)) {
  203. kmsg->msg_flags |= MSG_CTRUNC;
  204. return 0; /* XXX: return error? check spec. */
  205. }
  206. if (!COMPAT_USE_64BIT_TIME) {
  207. if (level == SOL_SOCKET && type == SO_TIMESTAMP_OLD) {
  208. struct __kernel_old_timeval *tv = (struct __kernel_old_timeval *)data;
  209. ctv.tv_sec = tv->tv_sec;
  210. ctv.tv_usec = tv->tv_usec;
  211. data = &ctv;
  212. len = sizeof(ctv);
  213. }
  214. if (level == SOL_SOCKET &&
  215. (type == SO_TIMESTAMPNS_OLD || type == SO_TIMESTAMPING_OLD)) {
  216. int count = type == SO_TIMESTAMPNS_OLD ? 1 : 3;
  217. int i;
  218. struct __kernel_old_timespec *ts = data;
  219. for (i = 0; i < count; i++) {
  220. cts[i].tv_sec = ts[i].tv_sec;
  221. cts[i].tv_nsec = ts[i].tv_nsec;
  222. }
  223. data = &cts;
  224. len = sizeof(cts[0]) * count;
  225. }
  226. }
  227. cmlen = CMSG_COMPAT_LEN(len);
  228. if (kmsg->msg_controllen < cmlen) {
  229. kmsg->msg_flags |= MSG_CTRUNC;
  230. cmlen = kmsg->msg_controllen;
  231. }
  232. cmhdr.cmsg_level = level;
  233. cmhdr.cmsg_type = type;
  234. cmhdr.cmsg_len = cmlen;
  235. if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
  236. return -EFAULT;
  237. if (copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr)))
  238. return -EFAULT;
  239. cmlen = CMSG_COMPAT_SPACE(len);
  240. if (kmsg->msg_controllen < cmlen)
  241. cmlen = kmsg->msg_controllen;
  242. kmsg->msg_control += cmlen;
  243. kmsg->msg_controllen -= cmlen;
  244. return 0;
  245. }
  246. static int scm_max_fds_compat(struct msghdr *msg)
  247. {
  248. if (msg->msg_controllen <= sizeof(struct compat_cmsghdr))
  249. return 0;
  250. return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
  251. }
  252. void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm)
  253. {
  254. struct compat_cmsghdr __user *cm =
  255. (struct compat_cmsghdr __user *)msg->msg_control;
  256. unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
  257. int fdmax = min_t(int, scm_max_fds_compat(msg), scm->fp->count);
  258. int __user *cmsg_data = CMSG_COMPAT_DATA(cm);
  259. int err = 0, i;
  260. for (i = 0; i < fdmax; i++) {
  261. err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
  262. if (err < 0)
  263. break;
  264. }
  265. if (i > 0) {
  266. int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
  267. err = put_user(SOL_SOCKET, &cm->cmsg_level);
  268. if (!err)
  269. err = put_user(SCM_RIGHTS, &cm->cmsg_type);
  270. if (!err)
  271. err = put_user(cmlen, &cm->cmsg_len);
  272. if (!err) {
  273. cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
  274. if (msg->msg_controllen < cmlen)
  275. cmlen = msg->msg_controllen;
  276. msg->msg_control += cmlen;
  277. msg->msg_controllen -= cmlen;
  278. }
  279. }
  280. if (i < scm->fp->count || (scm->fp->count && fdmax <= 0))
  281. msg->msg_flags |= MSG_CTRUNC;
  282. /*
  283. * All of the files that fit in the message have had their usage counts
  284. * incremented, so we just free the list.
  285. */
  286. __scm_destroy(scm);
  287. }
  288. /* Argument list sizes for compat_sys_socketcall */
  289. #define AL(x) ((x) * sizeof(u32))
  290. static unsigned char nas[21] = {
  291. AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
  292. AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
  293. AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
  294. AL(4), AL(5), AL(4)
  295. };
  296. #undef AL
  297. static inline long __compat_sys_sendmsg(int fd,
  298. struct compat_msghdr __user *msg,
  299. unsigned int flags)
  300. {
  301. return __sys_sendmsg(fd, (struct user_msghdr __user *)msg,
  302. flags | MSG_CMSG_COMPAT, false);
  303. }
  304. COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg,
  305. unsigned int, flags)
  306. {
  307. return __compat_sys_sendmsg(fd, msg, flags);
  308. }
  309. static inline long __compat_sys_sendmmsg(int fd,
  310. struct compat_mmsghdr __user *mmsg,
  311. unsigned int vlen, unsigned int flags)
  312. {
  313. return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
  314. flags | MSG_CMSG_COMPAT, false);
  315. }
  316. COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
  317. unsigned int, vlen, unsigned int, flags)
  318. {
  319. return __compat_sys_sendmmsg(fd, mmsg, vlen, flags);
  320. }
  321. static inline long __compat_sys_recvmsg(int fd,
  322. struct compat_msghdr __user *msg,
  323. unsigned int flags)
  324. {
  325. return __sys_recvmsg(fd, (struct user_msghdr __user *)msg,
  326. flags | MSG_CMSG_COMPAT, false);
  327. }
  328. COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg,
  329. unsigned int, flags)
  330. {
  331. return __compat_sys_recvmsg(fd, msg, flags);
  332. }
  333. static inline long __compat_sys_recvfrom(int fd, void __user *buf,
  334. compat_size_t len, unsigned int flags,
  335. struct sockaddr __user *addr,
  336. int __user *addrlen)
  337. {
  338. return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr,
  339. addrlen);
  340. }
  341. COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)
  342. {
  343. return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL);
  344. }
  345. COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len,
  346. unsigned int, flags, struct sockaddr __user *, addr,
  347. int __user *, addrlen)
  348. {
  349. return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
  350. }
  351. COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg,
  352. unsigned int, vlen, unsigned int, flags,
  353. struct __kernel_timespec __user *, timeout)
  354. {
  355. return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
  356. flags | MSG_CMSG_COMPAT, timeout, NULL);
  357. }
  358. #ifdef CONFIG_COMPAT_32BIT_TIME
  359. COMPAT_SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct compat_mmsghdr __user *, mmsg,
  360. unsigned int, vlen, unsigned int, flags,
  361. struct old_timespec32 __user *, timeout)
  362. {
  363. return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
  364. flags | MSG_CMSG_COMPAT, NULL, timeout);
  365. }
  366. #endif
  367. COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
  368. {
  369. u32 a[AUDITSC_ARGS];
  370. unsigned int len;
  371. u32 a0, a1;
  372. int ret;
  373. if (call < SYS_SOCKET || call > SYS_SENDMMSG)
  374. return -EINVAL;
  375. len = nas[call];
  376. if (len > sizeof(a))
  377. return -EINVAL;
  378. if (copy_from_user(a, args, len))
  379. return -EFAULT;
  380. ret = audit_socketcall_compat(len / sizeof(a[0]), a);
  381. if (ret)
  382. return ret;
  383. a0 = a[0];
  384. a1 = a[1];
  385. switch (call) {
  386. case SYS_SOCKET:
  387. ret = __sys_socket(a0, a1, a[2]);
  388. break;
  389. case SYS_BIND:
  390. ret = __sys_bind(a0, compat_ptr(a1), a[2]);
  391. break;
  392. case SYS_CONNECT:
  393. ret = __sys_connect(a0, compat_ptr(a1), a[2]);
  394. break;
  395. case SYS_LISTEN:
  396. ret = __sys_listen(a0, a1);
  397. break;
  398. case SYS_ACCEPT:
  399. ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
  400. break;
  401. case SYS_GETSOCKNAME:
  402. ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
  403. break;
  404. case SYS_GETPEERNAME:
  405. ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
  406. break;
  407. case SYS_SOCKETPAIR:
  408. ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
  409. break;
  410. case SYS_SEND:
  411. ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3], NULL, 0);
  412. break;
  413. case SYS_SENDTO:
  414. ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3],
  415. compat_ptr(a[4]), a[5]);
  416. break;
  417. case SYS_RECV:
  418. ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
  419. NULL, NULL);
  420. break;
  421. case SYS_RECVFROM:
  422. ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
  423. compat_ptr(a[4]),
  424. compat_ptr(a[5]));
  425. break;
  426. case SYS_SHUTDOWN:
  427. ret = __sys_shutdown(a0, a1);
  428. break;
  429. case SYS_SETSOCKOPT:
  430. ret = __sys_setsockopt(a0, a1, a[2], compat_ptr(a[3]), a[4]);
  431. break;
  432. case SYS_GETSOCKOPT:
  433. ret = __sys_getsockopt(a0, a1, a[2], compat_ptr(a[3]),
  434. compat_ptr(a[4]));
  435. break;
  436. case SYS_SENDMSG:
  437. ret = __compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
  438. break;
  439. case SYS_SENDMMSG:
  440. ret = __compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
  441. break;
  442. case SYS_RECVMSG:
  443. ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
  444. break;
  445. case SYS_RECVMMSG:
  446. ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2],
  447. a[3] | MSG_CMSG_COMPAT, NULL,
  448. compat_ptr(a[4]));
  449. break;
  450. case SYS_ACCEPT4:
  451. ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
  452. break;
  453. default:
  454. ret = -EINVAL;
  455. break;
  456. }
  457. return ret;
  458. }