Thomas Gleixner | 2874c5f | 2019-05-27 08:55:01 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/signal.h> |
Randy Dunlap | 4fc268d | 2006-01-11 12:17:47 -0800 | [diff] [blame] | 10 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/errno.h> |
| 12 | #include <linux/sched.h> |
Ingo Molnar | 8703e8a | 2017-02-08 18:51:30 +0100 | [diff] [blame] | 13 | #include <linux/sched/user.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/mm.h> |
| 15 | #include <linux/kernel.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Eric W. Biederman | 92f28d9 | 2013-03-15 01:03:33 -0700 | [diff] [blame] | 24 | #include <linux/pid_namespace.h> |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 25 | #include <linux/pid.h> |
| 26 | #include <linux/nsproxy.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 27 | #include <linux/slab.h> |
Deepa Dinamani | 9718475 | 2019-02-02 07:34:51 -0800 | [diff] [blame] | 28 | #include <linux/errqueue.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 30 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Daniel Wagner | d842950 | 2013-01-21 21:09:00 +0000 | [diff] [blame] | 37 | #include <net/cls_cgroup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
| 39 | |
| 40 | /* |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 41 | * Only allow a user to send credentials, that they could set with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | * setu(g)id. |
| 43 | */ |
| 44 | |
| 45 | static __inline__ int scm_check_creds(struct ucred *creds) |
| 46 | { |
David Howells | 86a264a | 2008-11-14 10:39:18 +1100 | [diff] [blame] | 47 | const struct cred *cred = current_cred(); |
Eric W. Biederman | b2e4f54 | 2012-05-23 16:39:45 -0600 | [diff] [blame] | 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; |
David Howells | b6dff3e | 2008-11-14 10:39:16 +1100 | [diff] [blame] | 53 | |
Eric W. Biederman | 92f28d9 | 2013-03-15 01:03:33 -0700 | [diff] [blame] | 54 | if ((creds->pid == task_tgid_vnr(current) || |
Andy Lutomirski | d661684 | 2013-08-22 11:39:15 -0700 | [diff] [blame] | 55 | ns_capable(task_active_pid_ns(current)->user_ns, CAP_SYS_ADMIN)) && |
Eric W. Biederman | b2e4f54 | 2012-05-23 16:39:45 -0600 | [diff] [blame] | 56 | ((uid_eq(uid, cred->uid) || uid_eq(uid, cred->euid) || |
Eric W. Biederman | c7b96ac | 2013-03-20 12:49:49 -0700 | [diff] [blame] | 57 | uid_eq(uid, cred->suid)) || ns_capable(cred->user_ns, CAP_SETUID)) && |
Eric W. Biederman | b2e4f54 | 2012-05-23 16:39:45 -0600 | [diff] [blame] | 58 | ((gid_eq(gid, cred->gid) || gid_eq(gid, cred->egid) || |
Eric W. Biederman | c7b96ac | 2013-03-20 12:49:49 -0700 | [diff] [blame] | 59 | gid_eq(gid, cred->sgid)) || ns_capable(cred->user_ns, CAP_SETGID))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
yuan linyu | 1ff8ceb | 2017-01-03 20:42:17 +0800 | [diff] [blame] | 72 | num = (cmsg->cmsg_len - sizeof(struct cmsghdr))/sizeof(int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Eric Dumazet | bba14de | 2010-11-23 14:09:15 +0000 | [diff] [blame] | 87 | fpl->max = SCM_MAX_FD; |
Hannes Frederic Sowa | 415e3d3 | 2016-02-03 02:11:03 +0100 | [diff] [blame] | 88 | fpl->user = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | } |
| 90 | fpp = &fpl->fp[fpl->count]; |
| 91 | |
Eric Dumazet | bba14de | 2010-11-23 14:09:15 +0000 | [diff] [blame] | 92 | if (fpl->count + num > fpl->max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | return -EINVAL; |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 94 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | /* |
| 96 | * Verify the descriptors and increment the usage count. |
| 97 | */ |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 98 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | for (i=0; i< num; i++) |
| 100 | { |
| 101 | int fd = fdp[i]; |
| 102 | struct file *file; |
| 103 | |
Al Viro | 326be7b | 2011-03-13 17:08:22 -0400 | [diff] [blame] | 104 | if (fd < 0 || !(file = fget_raw(fd))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | return -EBADF; |
| 106 | *fpp++ = file; |
| 107 | fpl->count++; |
| 108 | } |
Hannes Frederic Sowa | 415e3d3 | 2016-02-03 02:11:03 +0100 | [diff] [blame] | 109 | |
| 110 | if (!fpl->user) |
| 111 | fpl->user = get_uid(current_user()); |
| 112 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Al Viro | 6120d3d | 2012-06-24 10:03:05 +0400 | [diff] [blame] | 123 | for (i=fpl->count-1; i>=0; i--) |
| 124 | fput(fpl->fp[i]); |
Hannes Frederic Sowa | 415e3d3 | 2016-02-03 02:11:03 +0100 | [diff] [blame] | 125 | free_uid(fpl->user); |
Al Viro | 6120d3d | 2012-06-24 10:03:05 +0400 | [diff] [blame] | 126 | kfree(fpl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | } |
| 128 | } |
Eric Dumazet | 9e34a5b | 2010-07-09 21:22:04 +0000 | [diff] [blame] | 129 | EXPORT_SYMBOL(__scm_destroy); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
| 131 | int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p) |
| 132 | { |
| 133 | struct cmsghdr *cmsg; |
| 134 | int err; |
| 135 | |
Gu Zheng | f95b414 | 2014-12-11 11:22:04 +0800 | [diff] [blame] | 136 | for_each_cmsghdr(cmsg, msg) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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. |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 143 | But if cmsg_level is not SOL_SOCKET, we do not check |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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: |
Eric W. Biederman | 76dadd76 | 2010-02-28 01:20:36 +0000 | [diff] [blame] | 156 | if (!sock->ops || sock->ops->family != PF_UNIX) |
| 157 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | err=scm_fp_copy(cmsg, &p->fp); |
| 159 | if (err<0) |
| 160 | goto error; |
| 161 | break; |
| 162 | case SCM_CREDENTIALS: |
Eric W. Biederman | b2e4f54 | 2012-05-23 16:39:45 -0600 | [diff] [blame] | 163 | { |
Eric W. Biederman | dbe9a41 | 2012-09-06 18:20:01 +0000 | [diff] [blame] | 164 | struct ucred creds; |
Eric W. Biederman | b2e4f54 | 2012-05-23 16:39:45 -0600 | [diff] [blame] | 165 | kuid_t uid; |
| 166 | kgid_t gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred))) |
| 168 | goto error; |
Eric W. Biederman | dbe9a41 | 2012-09-06 18:20:01 +0000 | [diff] [blame] | 169 | memcpy(&creds, CMSG_DATA(cmsg), sizeof(struct ucred)); |
| 170 | err = scm_check_creds(&creds); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | if (err) |
| 172 | goto error; |
Eric W. Biederman | 257b535 | 2010-06-13 03:32:34 +0000 | [diff] [blame] | 173 | |
Eric W. Biederman | dbe9a41 | 2012-09-06 18:20:01 +0000 | [diff] [blame] | 174 | p->creds.pid = creds.pid; |
| 175 | if (!p->pid || pid_vnr(p->pid) != creds.pid) { |
Eric W. Biederman | 257b535 | 2010-06-13 03:32:34 +0000 | [diff] [blame] | 176 | struct pid *pid; |
| 177 | err = -ESRCH; |
Eric W. Biederman | dbe9a41 | 2012-09-06 18:20:01 +0000 | [diff] [blame] | 178 | pid = find_get_pid(creds.pid); |
Eric W. Biederman | 257b535 | 2010-06-13 03:32:34 +0000 | [diff] [blame] | 179 | if (!pid) |
| 180 | goto error; |
| 181 | put_pid(p->pid); |
| 182 | p->pid = pid; |
| 183 | } |
| 184 | |
Eric W. Biederman | b2e4f54 | 2012-05-23 16:39:45 -0600 | [diff] [blame] | 185 | err = -EINVAL; |
Eric W. Biederman | dbe9a41 | 2012-09-06 18:20:01 +0000 | [diff] [blame] | 186 | uid = make_kuid(current_user_ns(), creds.uid); |
| 187 | gid = make_kgid(current_user_ns(), creds.gid); |
Eric W. Biederman | b2e4f54 | 2012-05-23 16:39:45 -0600 | [diff] [blame] | 188 | if (!uid_valid(uid) || !gid_valid(gid)) |
| 189 | goto error; |
| 190 | |
Eric W. Biederman | dbe9a41 | 2012-09-06 18:20:01 +0000 | [diff] [blame] | 191 | p->creds.uid = uid; |
| 192 | p->creds.gid = gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | break; |
Eric W. Biederman | b2e4f54 | 2012-05-23 16:39:45 -0600 | [diff] [blame] | 194 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 206 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | error: |
| 208 | scm_destroy(p); |
| 209 | return err; |
| 210 | } |
Eric Dumazet | 9e34a5b | 2010-07-09 21:22:04 +0000 | [diff] [blame] | 211 | EXPORT_SYMBOL(__scm_send); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | |
| 213 | int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data) |
| 214 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | int cmlen = CMSG_LEN(len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | |
Christoph Hellwig | 1f466e1 | 2020-05-11 13:59:13 +0200 | [diff] [blame] | 217 | if (msg->msg_flags & MSG_CMSG_COMPAT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | return put_cmsg_compat(msg, level, type, len, data); |
| 219 | |
Christoph Hellwig | 1f466e1 | 2020-05-11 13:59:13 +0200 | [diff] [blame] | 220 | if (!msg->msg_control || msg->msg_controllen < sizeof(struct cmsghdr)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | msg->msg_flags |= MSG_CTRUNC; |
| 222 | return 0; /* XXX: return error? check spec. */ |
| 223 | } |
| 224 | if (msg->msg_controllen < cmlen) { |
| 225 | msg->msg_flags |= MSG_CTRUNC; |
| 226 | cmlen = msg->msg_controllen; |
| 227 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | |
Christoph Hellwig | 1f466e1 | 2020-05-11 13:59:13 +0200 | [diff] [blame] | 229 | if (msg->msg_control_is_user) { |
| 230 | struct cmsghdr __user *cm = msg->msg_control_user; |
| 231 | struct cmsghdr cmhdr; |
| 232 | |
| 233 | cmhdr.cmsg_level = level; |
| 234 | cmhdr.cmsg_type = type; |
| 235 | cmhdr.cmsg_len = cmlen; |
| 236 | if (copy_to_user(cm, &cmhdr, sizeof cmhdr) || |
| 237 | copy_to_user(CMSG_USER_DATA(cm), data, cmlen - sizeof(*cm))) |
| 238 | return -EFAULT; |
| 239 | } else { |
| 240 | struct cmsghdr *cm = msg->msg_control; |
| 241 | |
| 242 | cm->cmsg_level = level; |
| 243 | cm->cmsg_type = type; |
| 244 | cm->cmsg_len = cmlen; |
| 245 | memcpy(CMSG_DATA(cm), data, cmlen - sizeof(*cm)); |
| 246 | } |
| 247 | |
| 248 | cmlen = min(CMSG_SPACE(len), msg->msg_controllen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | msg->msg_control += cmlen; |
| 250 | msg->msg_controllen -= cmlen; |
Christoph Hellwig | 1f466e1 | 2020-05-11 13:59:13 +0200 | [diff] [blame] | 251 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | } |
Eric Dumazet | 9e34a5b | 2010-07-09 21:22:04 +0000 | [diff] [blame] | 253 | EXPORT_SYMBOL(put_cmsg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | |
Deepa Dinamani | 9718475 | 2019-02-02 07:34:51 -0800 | [diff] [blame] | 255 | void put_cmsg_scm_timestamping64(struct msghdr *msg, struct scm_timestamping_internal *tss_internal) |
| 256 | { |
| 257 | struct scm_timestamping64 tss; |
| 258 | int i; |
| 259 | |
| 260 | for (i = 0; i < ARRAY_SIZE(tss.ts); i++) { |
| 261 | tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec; |
| 262 | tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec; |
| 263 | } |
| 264 | |
| 265 | put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_NEW, sizeof(tss), &tss); |
| 266 | } |
| 267 | EXPORT_SYMBOL(put_cmsg_scm_timestamping64); |
| 268 | |
| 269 | void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_internal *tss_internal) |
| 270 | { |
| 271 | struct scm_timestamping tss; |
| 272 | int i; |
| 273 | |
Arnd Bergmann | 0309f98 | 2019-10-27 18:09:32 +0100 | [diff] [blame] | 274 | for (i = 0; i < ARRAY_SIZE(tss.ts); i++) { |
| 275 | tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec; |
| 276 | tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec; |
| 277 | } |
Deepa Dinamani | 9718475 | 2019-02-02 07:34:51 -0800 | [diff] [blame] | 278 | |
| 279 | put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_OLD, sizeof(tss), &tss); |
| 280 | } |
| 281 | EXPORT_SYMBOL(put_cmsg_scm_timestamping); |
| 282 | |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 283 | static int __scm_install_fd(struct file *file, int __user *ufd, int o_flags) |
| 284 | { |
| 285 | struct socket *sock; |
| 286 | int new_fd; |
| 287 | int error; |
| 288 | |
| 289 | error = security_file_receive(file); |
| 290 | if (error) |
| 291 | return error; |
| 292 | |
| 293 | new_fd = get_unused_fd_flags(o_flags); |
| 294 | if (new_fd < 0) |
| 295 | return new_fd; |
| 296 | |
| 297 | error = put_user(new_fd, ufd); |
| 298 | if (error) { |
| 299 | put_unused_fd(new_fd); |
| 300 | return error; |
| 301 | } |
| 302 | |
| 303 | /* Bump the usage count and install the file. */ |
| 304 | sock = sock_from_file(file, &error); |
| 305 | if (sock) { |
| 306 | sock_update_netprioidx(&sock->sk->sk_cgrp_data); |
| 307 | sock_update_classid(&sock->sk->sk_cgrp_data); |
| 308 | } |
| 309 | fd_install(new_fd, get_file(file)); |
Christoph Hellwig | 6e8a4f9 | 2020-05-13 13:07:59 +0200 | [diff] [blame] | 310 | return 0; |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 311 | } |
| 312 | |
| 313 | static int scm_max_fds(struct msghdr *msg) |
| 314 | { |
| 315 | if (msg->msg_controllen <= sizeof(struct cmsghdr)) |
| 316 | return 0; |
| 317 | return (msg->msg_controllen - sizeof(struct cmsghdr)) / sizeof(int); |
| 318 | } |
| 319 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) |
| 321 | { |
Stephen Hemminger | cfcabdc | 2007-10-09 01:59:42 -0700 | [diff] [blame] | 322 | struct cmsghdr __user *cm |
| 323 | = (__force struct cmsghdr __user*)msg->msg_control; |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 324 | int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; |
| 325 | int fdmax = min_t(int, scm_max_fds(msg), scm->fp->count); |
| 326 | int __user *cmsg_data = CMSG_USER_DATA(cm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | int err = 0, i; |
| 328 | |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 329 | if (msg->msg_flags & MSG_CMSG_COMPAT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | scm_detach_fds_compat(msg, scm); |
| 331 | return; |
| 332 | } |
| 333 | |
Christoph Hellwig | 1f466e1 | 2020-05-11 13:59:13 +0200 | [diff] [blame] | 334 | /* no use for FD passing from kernel space callers */ |
| 335 | if (WARN_ON_ONCE(!msg->msg_control_is_user)) |
| 336 | return; |
| 337 | |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 338 | for (i = 0; i < fdmax; i++) { |
| 339 | err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | if (err) |
| 341 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | } |
| 343 | |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 344 | if (i > 0) { |
| 345 | int cmlen = CMSG_LEN(i * sizeof(int)); |
| 346 | |
Miklos Szeredi | effee6a | 2006-10-09 21:42:14 -0700 | [diff] [blame] | 347 | err = put_user(SOL_SOCKET, &cm->cmsg_level); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | if (!err) |
| 349 | err = put_user(SCM_RIGHTS, &cm->cmsg_type); |
| 350 | if (!err) |
| 351 | err = put_user(cmlen, &cm->cmsg_len); |
| 352 | if (!err) { |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 353 | cmlen = CMSG_SPACE(i * sizeof(int)); |
Daniel Borkmann | 6900317 | 2015-11-20 00:11:56 +0100 | [diff] [blame] | 354 | if (msg->msg_controllen < cmlen) |
| 355 | cmlen = msg->msg_controllen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | msg->msg_control += cmlen; |
| 357 | msg->msg_controllen -= cmlen; |
| 358 | } |
| 359 | } |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 360 | |
| 361 | if (i < scm->fp->count || (scm->fp->count && fdmax <= 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | msg->msg_flags |= MSG_CTRUNC; |
| 363 | |
| 364 | /* |
Christoph Hellwig | 2618d53 | 2020-05-11 13:59:12 +0200 | [diff] [blame] | 365 | * All of the files that fit in the message have had their usage counts |
| 366 | * incremented, so we just free the list. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | */ |
| 368 | __scm_destroy(scm); |
| 369 | } |
Eric Dumazet | 9e34a5b | 2010-07-09 21:22:04 +0000 | [diff] [blame] | 370 | EXPORT_SYMBOL(scm_detach_fds); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | |
| 372 | struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl) |
| 373 | { |
| 374 | struct scm_fp_list *new_fpl; |
| 375 | int i; |
| 376 | |
| 377 | if (!fpl) |
| 378 | return NULL; |
| 379 | |
Eric Dumazet | bba14de | 2010-11-23 14:09:15 +0000 | [diff] [blame] | 380 | new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]), |
| 381 | GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | if (new_fpl) { |
Eric Dumazet | bba14de | 2010-11-23 14:09:15 +0000 | [diff] [blame] | 383 | for (i = 0; i < fpl->count; i++) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | get_file(fpl->fp[i]); |
Eric Dumazet | bba14de | 2010-11-23 14:09:15 +0000 | [diff] [blame] | 385 | new_fpl->max = new_fpl->count; |
Hannes Frederic Sowa | 415e3d3 | 2016-02-03 02:11:03 +0100 | [diff] [blame] | 386 | new_fpl->user = get_uid(fpl->user); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | } |
| 388 | return new_fpl; |
| 389 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | EXPORT_SYMBOL(scm_fp_dup); |