xref: /linux/kernel/uid16.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98)
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/utsname.h>
8 #include <linux/mman.h>
9 #include <linux/smp_lock.h>
10 #include <linux/notifier.h>
11 #include <linux/reboot.h>
12 #include <linux/prctl.h>
13 #include <linux/capability.h>
14 #include <linux/init.h>
15 #include <linux/highuid.h>
16 #include <linux/security.h>
17 #include <linux/syscalls.h>
18 
19 #include <asm/uaccess.h>
20 
21 asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gid_t group)
22 {
23 	return sys_chown(filename, low2highuid(user), low2highgid(group));
24 }
25 
26 asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_gid_t group)
27 {
28 	return sys_lchown(filename, low2highuid(user), low2highgid(group));
29 }
30 
31 asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
32 {
33 	return sys_fchown(fd, low2highuid(user), low2highgid(group));
34 }
35 
36 asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
37 {
38 	return sys_setregid(low2highgid(rgid), low2highgid(egid));
39 }
40 
41 asmlinkage long sys_setgid16(old_gid_t gid)
42 {
43 	return sys_setgid(low2highgid(gid));
44 }
45 
46 asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
47 {
48 	return sys_setreuid(low2highuid(ruid), low2highuid(euid));
49 }
50 
51 asmlinkage long sys_setuid16(old_uid_t uid)
52 {
53 	return sys_setuid(low2highuid(uid));
54 }
55 
56 asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
57 {
58 	return sys_setresuid(low2highuid(ruid), low2highuid(euid),
59 		low2highuid(suid));
60 }
61 
62 asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
63 {
64 	int retval;
65 
66 	if (!(retval = put_user(high2lowuid(current->uid), ruid)) &&
67 	    !(retval = put_user(high2lowuid(current->euid), euid)))
68 		retval = put_user(high2lowuid(current->suid), suid);
69 
70 	return retval;
71 }
72 
73 asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
74 {
75 	return sys_setresgid(low2highgid(rgid), low2highgid(egid),
76 		low2highgid(sgid));
77 }
78 
79 asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
80 {
81 	int retval;
82 
83 	if (!(retval = put_user(high2lowgid(current->gid), rgid)) &&
84 	    !(retval = put_user(high2lowgid(current->egid), egid)))
85 		retval = put_user(high2lowgid(current->sgid), sgid);
86 
87 	return retval;
88 }
89 
90 asmlinkage long sys_setfsuid16(old_uid_t uid)
91 {
92 	return sys_setfsuid(low2highuid(uid));
93 }
94 
95 asmlinkage long sys_setfsgid16(old_gid_t gid)
96 {
97 	return sys_setfsgid(low2highgid(gid));
98 }
99 
100 static int groups16_to_user(old_gid_t __user *grouplist,
101     struct group_info *group_info)
102 {
103 	int i;
104 	old_gid_t group;
105 
106 	for (i = 0; i < group_info->ngroups; i++) {
107 		group = high2lowgid(GROUP_AT(group_info, i));
108 		if (put_user(group, grouplist+i))
109 			return -EFAULT;
110 	}
111 
112 	return 0;
113 }
114 
115 static int groups16_from_user(struct group_info *group_info,
116     old_gid_t __user *grouplist)
117 {
118 	int i;
119 	old_gid_t group;
120 
121 	for (i = 0; i < group_info->ngroups; i++) {
122 		if (get_user(group, grouplist+i))
123 			return  -EFAULT;
124 		GROUP_AT(group_info, i) = low2highgid(group);
125 	}
126 
127 	return 0;
128 }
129 
130 asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
131 {
132 	int i = 0;
133 
134 	if (gidsetsize < 0)
135 		return -EINVAL;
136 
137 	get_group_info(current->group_info);
138 	i = current->group_info->ngroups;
139 	if (gidsetsize) {
140 		if (i > gidsetsize) {
141 			i = -EINVAL;
142 			goto out;
143 		}
144 		if (groups16_to_user(grouplist, current->group_info)) {
145 			i = -EFAULT;
146 			goto out;
147 		}
148 	}
149 out:
150 	put_group_info(current->group_info);
151 	return i;
152 }
153 
154 asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
155 {
156 	struct group_info *group_info;
157 	int retval;
158 
159 	if (!capable(CAP_SETGID))
160 		return -EPERM;
161 	if ((unsigned)gidsetsize > NGROUPS_MAX)
162 		return -EINVAL;
163 
164 	group_info = groups_alloc(gidsetsize);
165 	if (!group_info)
166 		return -ENOMEM;
167 	retval = groups16_from_user(group_info, grouplist);
168 	if (retval) {
169 		put_group_info(group_info);
170 		return retval;
171 	}
172 
173 	retval = set_current_groups(group_info);
174 	put_group_info(group_info);
175 
176 	return retval;
177 }
178 
179 asmlinkage long sys_getuid16(void)
180 {
181 	return high2lowuid(current->uid);
182 }
183 
184 asmlinkage long sys_geteuid16(void)
185 {
186 	return high2lowuid(current->euid);
187 }
188 
189 asmlinkage long sys_getgid16(void)
190 {
191 	return high2lowgid(current->gid);
192 }
193 
194 asmlinkage long sys_getegid16(void)
195 {
196 	return high2lowgid(current->egid);
197 }
198