Root/kernel/uid16.c

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

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