aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/uid16.c
blob: 37f48c049a2a6ea6853f4885bb36af1e25cc5a56 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
/*
 *	Wrapper functions for 16bit uid back compatibility. All nicely tied
 *	together in the faint hope we can take the out in five years time.
 */

#include <linux/mm.h>
#include <linux/utsname.h>
#include <linux/mman.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/prctl.h>
#include <linux/capability.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/security.h>
#include <linux/syscalls.h>

#include <asm/uaccess.h>

SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
{
	long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(3, ret, filename, user, group);
	return ret;
}

SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
{
	long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(3, ret, filename, user, group);
	return ret;
}

SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
{
	long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(3, ret, fd, user, group);
	return ret;
}

asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
{
	long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(2, ret, rgid, egid);
	return ret;
}

asmlinkage long sys_setgid16(old_gid_t gid)
{
	long ret = sys_setgid(low2highgid(gid));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(1, ret, gid);
	return ret;
}

asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
{
	long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(2, ret, ruid, euid);
	return ret;
}

asmlinkage long sys_setuid16(old_uid_t uid)
{
	long ret = sys_setuid(low2highuid(uid));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(1, ret, uid);
	return ret;
}

asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
{
	long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
				 low2highuid(suid));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(3, ret, ruid, euid, suid);
	return ret;
}

asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
{
	const struct cred *cred = current_cred();
	int retval;

	if (!(retval   = put_user(high2lowuid(cred->uid),  ruid)) &&
	    !(retval   = put_user(high2lowuid(cred->euid), euid)))
		retval = put_user(high2lowuid(cred->suid), suid);

	return retval;
}

asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
{
	long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
				 low2highgid(sgid));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(3, ret, rgid, egid, sgid);
	return ret;
}

asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
{
	const struct cred *cred = current_cred();
	int retval;

	if (!(retval   = put_user(high2lowgid(cred->gid),  rgid)) &&
	    !(retval   = put_user(high2lowgid(cred->egid), egid)))
		retval = put_user(high2lowgid(cred->sgid), sgid);

	return retval;
}

asmlinkage long sys_setfsuid16(old_uid_t uid)
{
	long ret = sys_setfsuid(low2highuid(uid));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(1, ret, uid);
	return ret;
}

asmlinkage long sys_setfsgid16(old_gid_t gid)
{
	long ret = sys_setfsgid(low2highgid(gid));
	/* avoid REGPARM breakage on x86: */
	asmlinkage_protect(1, ret, gid);
	return ret;
}

static int groups16_to_user(old_gid_t __user *grouplist,
    struct group_info *group_info)
{
	int i;
	old_gid_t group;

	for (i = 0; i < group_info->ngroups; i++) {
		group = high2lowgid(GROUP_AT(group_info, i));
		if (put_user(group, grouplist+i))
			return -EFAULT;
	}

	return 0;
}

static int groups16_from_user(struct group_info *group_info,
    old_gid_t __user *grouplist)
{
	int i;
	old_gid_t group;

	for (i = 0; i < group_info->ngroups; i++) {
		if (get_user(group, grouplist+i))
			return  -EFAULT;
		GROUP_AT(group_info, i) = low2highgid(group);
	}

	return 0;
}

asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
{
	const struct cred *cred = current_cred();
	int i;

	if (gidsetsize < 0)
		return -EINVAL;

	i = cred->group_info->ngroups;
	if (gidsetsize) {
		if (i > gidsetsize) {
			i = -EINVAL;
			goto out;
		}
		if (groups16_to_user(grouplist, cred->group_info)) {
			i = -EFAULT;
			goto out;
		}
	}
out:
	return i;
}

asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
{
	struct group_info *group_info;
	int retval;

	if (!capable(CAP_SETGID))
		return -EPERM;
	if ((unsigned)gidsetsize > NGROUPS_MAX)
		return -EINVAL;

	group_info = groups_alloc(gidsetsize);
	if (!group_info)
		return -ENOMEM;
	retval = groups16_from_user(group_info, grouplist);
	if (retval) {
		put_group_info(group_info);
		return retval;
	}

	retval = set_current_groups(group_info);
	put_group_info(group_info);

	return retval;
}

asmlinkage long sys_getuid16(void)
{
	return high2lowuid(current_uid());
}

asmlinkage long sys_geteuid16(void)
{
	return high2lowuid(current_euid());
}

asmlinkage long sys_getgid16(void)
{
	return high2lowgid(current_gid());
}

asmlinkage long sys_getegid16(void)
{
	return high2lowgid(current_egid());
}