Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszer...
[platform/kernel/linux-starfive.git] / kernel / uid16.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *      Wrapper functions for 16bit uid back compatibility. All nicely tied
4  *      together in the faint hope we can take the out in five years time.
5  */
6
7 #include <linux/mm.h>
8 #include <linux/mman.h>
9 #include <linux/notifier.h>
10 #include <linux/reboot.h>
11 #include <linux/prctl.h>
12 #include <linux/capability.h>
13 #include <linux/init.h>
14 #include <linux/highuid.h>
15 #include <linux/security.h>
16 #include <linux/cred.h>
17 #include <linux/syscalls.h>
18
19 #include <linux/uaccess.h>
20
21 #include "uid16.h"
22
23 SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
24 {
25         return ksys_chown(filename, low2highuid(user), low2highgid(group));
26 }
27
28 SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
29 {
30         return ksys_lchown(filename, low2highuid(user), low2highgid(group));
31 }
32
33 SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
34 {
35         return ksys_fchown(fd, low2highuid(user), low2highgid(group));
36 }
37
38 SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)
39 {
40         return __sys_setregid(low2highgid(rgid), low2highgid(egid));
41 }
42
43 SYSCALL_DEFINE1(setgid16, old_gid_t, gid)
44 {
45         return __sys_setgid(low2highgid(gid));
46 }
47
48 SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)
49 {
50         return __sys_setreuid(low2highuid(ruid), low2highuid(euid));
51 }
52
53 SYSCALL_DEFINE1(setuid16, old_uid_t, uid)
54 {
55         return __sys_setuid(low2highuid(uid));
56 }
57
58 SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)
59 {
60         return __sys_setresuid(low2highuid(ruid), low2highuid(euid),
61                                  low2highuid(suid));
62 }
63
64 SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruidp, old_uid_t __user *, euidp, old_uid_t __user *, suidp)
65 {
66         const struct cred *cred = current_cred();
67         int retval;
68         old_uid_t ruid, euid, suid;
69
70         ruid = high2lowuid(from_kuid_munged(cred->user_ns, cred->uid));
71         euid = high2lowuid(from_kuid_munged(cred->user_ns, cred->euid));
72         suid = high2lowuid(from_kuid_munged(cred->user_ns, cred->suid));
73
74         if (!(retval   = put_user(ruid, ruidp)) &&
75             !(retval   = put_user(euid, euidp)))
76                 retval = put_user(suid, suidp);
77
78         return retval;
79 }
80
81 SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid)
82 {
83         return __sys_setresgid(low2highgid(rgid), low2highgid(egid),
84                                  low2highgid(sgid));
85 }
86
87 SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgidp, old_gid_t __user *, egidp, old_gid_t __user *, sgidp)
88 {
89         const struct cred *cred = current_cred();
90         int retval;
91         old_gid_t rgid, egid, sgid;
92
93         rgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->gid));
94         egid = high2lowgid(from_kgid_munged(cred->user_ns, cred->egid));
95         sgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->sgid));
96
97         if (!(retval   = put_user(rgid, rgidp)) &&
98             !(retval   = put_user(egid, egidp)))
99                 retval = put_user(sgid, sgidp);
100
101         return retval;
102 }
103
104 SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)
105 {
106         return __sys_setfsuid(low2highuid(uid));
107 }
108
109 SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
110 {
111         return __sys_setfsgid(low2highgid(gid));
112 }
113
114 static int groups16_to_user(old_gid_t __user *grouplist,
115     struct group_info *group_info)
116 {
117         struct user_namespace *user_ns = current_user_ns();
118         int i;
119         old_gid_t group;
120         kgid_t kgid;
121
122         for (i = 0; i < group_info->ngroups; i++) {
123                 kgid = group_info->gid[i];
124                 group = high2lowgid(from_kgid_munged(user_ns, kgid));
125                 if (put_user(group, grouplist+i))
126                         return -EFAULT;
127         }
128
129         return 0;
130 }
131
132 static int groups16_from_user(struct group_info *group_info,
133     old_gid_t __user *grouplist)
134 {
135         struct user_namespace *user_ns = current_user_ns();
136         int i;
137         old_gid_t group;
138         kgid_t kgid;
139
140         for (i = 0; i < group_info->ngroups; i++) {
141                 if (get_user(group, grouplist+i))
142                         return  -EFAULT;
143
144                 kgid = make_kgid(user_ns, low2highgid(group));
145                 if (!gid_valid(kgid))
146                         return -EINVAL;
147
148                 group_info->gid[i] = kgid;
149         }
150
151         return 0;
152 }
153
154 SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
155 {
156         const struct cred *cred = current_cred();
157         int i;
158
159         if (gidsetsize < 0)
160                 return -EINVAL;
161
162         i = cred->group_info->ngroups;
163         if (gidsetsize) {
164                 if (i > gidsetsize) {
165                         i = -EINVAL;
166                         goto out;
167                 }
168                 if (groups16_to_user(grouplist, cred->group_info)) {
169                         i = -EFAULT;
170                         goto out;
171                 }
172         }
173 out:
174         return i;
175 }
176
177 SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
178 {
179         struct group_info *group_info;
180         int retval;
181
182         if (!may_setgroups())
183                 return -EPERM;
184         if ((unsigned)gidsetsize > NGROUPS_MAX)
185                 return -EINVAL;
186
187         group_info = groups_alloc(gidsetsize);
188         if (!group_info)
189                 return -ENOMEM;
190         retval = groups16_from_user(group_info, grouplist);
191         if (retval) {
192                 put_group_info(group_info);
193                 return retval;
194         }
195
196         groups_sort(group_info);
197         retval = set_current_groups(group_info);
198         put_group_info(group_info);
199
200         return retval;
201 }
202
203 SYSCALL_DEFINE0(getuid16)
204 {
205         return high2lowuid(from_kuid_munged(current_user_ns(), current_uid()));
206 }
207
208 SYSCALL_DEFINE0(geteuid16)
209 {
210         return high2lowuid(from_kuid_munged(current_user_ns(), current_euid()));
211 }
212
213 SYSCALL_DEFINE0(getgid16)
214 {
215         return high2lowgid(from_kgid_munged(current_user_ns(), current_gid()));
216 }
217
218 SYSCALL_DEFINE0(getegid16)
219 {
220         return high2lowgid(from_kgid_munged(current_user_ns(), current_egid()));
221 }