xref: /openbmc/linux/kernel/uid16.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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/init.h>
14 #include <linux/highuid.h>
15 #include <linux/security.h>
16 #include <linux/syscalls.h>
17 
18 #include <asm/uaccess.h>
19 
20 asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gid_t group)
21 {
22 	return sys_chown(filename, low2highuid(user), low2highgid(group));
23 }
24 
25 asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_gid_t group)
26 {
27 	return sys_lchown(filename, low2highuid(user), low2highgid(group));
28 }
29 
30 asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
31 {
32 	return sys_fchown(fd, low2highuid(user), low2highgid(group));
33 }
34 
35 asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
36 {
37 	return sys_setregid(low2highgid(rgid), low2highgid(egid));
38 }
39 
40 asmlinkage long sys_setgid16(old_gid_t gid)
41 {
42 	return sys_setgid(low2highgid(gid));
43 }
44 
45 asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
46 {
47 	return sys_setreuid(low2highuid(ruid), low2highuid(euid));
48 }
49 
50 asmlinkage long sys_setuid16(old_uid_t uid)
51 {
52 	return sys_setuid(low2highuid(uid));
53 }
54 
55 asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
56 {
57 	return sys_setresuid(low2highuid(ruid), low2highuid(euid),
58 		low2highuid(suid));
59 }
60 
61 asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
62 {
63 	int retval;
64 
65 	if (!(retval = put_user(high2lowuid(current->uid), ruid)) &&
66 	    !(retval = put_user(high2lowuid(current->euid), euid)))
67 		retval = put_user(high2lowuid(current->suid), suid);
68 
69 	return retval;
70 }
71 
72 asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
73 {
74 	return sys_setresgid(low2highgid(rgid), low2highgid(egid),
75 		low2highgid(sgid));
76 }
77 
78 asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
79 {
80 	int retval;
81 
82 	if (!(retval = put_user(high2lowgid(current->gid), rgid)) &&
83 	    !(retval = put_user(high2lowgid(current->egid), egid)))
84 		retval = put_user(high2lowgid(current->sgid), sgid);
85 
86 	return retval;
87 }
88 
89 asmlinkage long sys_setfsuid16(old_uid_t uid)
90 {
91 	return sys_setfsuid(low2highuid(uid));
92 }
93 
94 asmlinkage long sys_setfsgid16(old_gid_t gid)
95 {
96 	return sys_setfsgid(low2highgid(gid));
97 }
98 
99 static int groups16_to_user(old_gid_t __user *grouplist,
100     struct group_info *group_info)
101 {
102 	int i;
103 	old_gid_t group;
104 
105 	for (i = 0; i < group_info->ngroups; i++) {
106 		group = high2lowgid(GROUP_AT(group_info, i));
107 		if (put_user(group, grouplist+i))
108 			return -EFAULT;
109 	}
110 
111 	return 0;
112 }
113 
114 static int groups16_from_user(struct group_info *group_info,
115     old_gid_t __user *grouplist)
116 {
117 	int i;
118 	old_gid_t group;
119 
120 	for (i = 0; i < group_info->ngroups; i++) {
121 		if (get_user(group, grouplist+i))
122 			return  -EFAULT;
123 		GROUP_AT(group_info, i) = low2highgid(group);
124 	}
125 
126 	return 0;
127 }
128 
129 asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
130 {
131 	int i = 0;
132 
133 	if (gidsetsize < 0)
134 		return -EINVAL;
135 
136 	get_group_info(current->group_info);
137 	i = current->group_info->ngroups;
138 	if (gidsetsize) {
139 		if (i > gidsetsize) {
140 			i = -EINVAL;
141 			goto out;
142 		}
143 		if (groups16_to_user(grouplist, current->group_info)) {
144 			i = -EFAULT;
145 			goto out;
146 		}
147 	}
148 out:
149 	put_group_info(current->group_info);
150 	return i;
151 }
152 
153 asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
154 {
155 	struct group_info *group_info;
156 	int retval;
157 
158 	if (!capable(CAP_SETGID))
159 		return -EPERM;
160 	if ((unsigned)gidsetsize > NGROUPS_MAX)
161 		return -EINVAL;
162 
163 	group_info = groups_alloc(gidsetsize);
164 	if (!group_info)
165 		return -ENOMEM;
166 	retval = groups16_from_user(group_info, grouplist);
167 	if (retval) {
168 		put_group_info(group_info);
169 		return retval;
170 	}
171 
172 	retval = set_current_groups(group_info);
173 	put_group_info(group_info);
174 
175 	return retval;
176 }
177 
178 asmlinkage long sys_getuid16(void)
179 {
180 	return high2lowuid(current->uid);
181 }
182 
183 asmlinkage long sys_geteuid16(void)
184 {
185 	return high2lowuid(current->euid);
186 }
187 
188 asmlinkage long sys_getgid16(void)
189 {
190 	return high2lowgid(current->gid);
191 }
192 
193 asmlinkage long sys_getegid16(void)
194 {
195 	return high2lowgid(current->egid);
196 }
197