[CVE-2009-0029] System call wrappers part 17
[linux-3.10.git] / 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/utsname.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/syscalls.h>
17
18 #include <asm/uaccess.h>
19
20 SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
21 {
22         long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
23         /* avoid REGPARM breakage on x86: */
24         asmlinkage_protect(3, ret, filename, user, group);
25         return ret;
26 }
27
28 SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
29 {
30         long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
31         /* avoid REGPARM breakage on x86: */
32         asmlinkage_protect(3, ret, filename, user, group);
33         return ret;
34 }
35
36 SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
37 {
38         long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
39         /* avoid REGPARM breakage on x86: */
40         asmlinkage_protect(3, ret, fd, user, group);
41         return ret;
42 }
43
44 asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
45 {
46         long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
47         /* avoid REGPARM breakage on x86: */
48         asmlinkage_protect(2, ret, rgid, egid);
49         return ret;
50 }
51
52 asmlinkage long sys_setgid16(old_gid_t gid)
53 {
54         long ret = sys_setgid(low2highgid(gid));
55         /* avoid REGPARM breakage on x86: */
56         asmlinkage_protect(1, ret, gid);
57         return ret;
58 }
59
60 asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
61 {
62         long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
63         /* avoid REGPARM breakage on x86: */
64         asmlinkage_protect(2, ret, ruid, euid);
65         return ret;
66 }
67
68 asmlinkage long sys_setuid16(old_uid_t uid)
69 {
70         long ret = sys_setuid(low2highuid(uid));
71         /* avoid REGPARM breakage on x86: */
72         asmlinkage_protect(1, ret, uid);
73         return ret;
74 }
75
76 asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
77 {
78         long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
79                                  low2highuid(suid));
80         /* avoid REGPARM breakage on x86: */
81         asmlinkage_protect(3, ret, ruid, euid, suid);
82         return ret;
83 }
84
85 asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
86 {
87         const struct cred *cred = current_cred();
88         int retval;
89
90         if (!(retval   = put_user(high2lowuid(cred->uid),  ruid)) &&
91             !(retval   = put_user(high2lowuid(cred->euid), euid)))
92                 retval = put_user(high2lowuid(cred->suid), suid);
93
94         return retval;
95 }
96
97 asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
98 {
99         long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
100                                  low2highgid(sgid));
101         /* avoid REGPARM breakage on x86: */
102         asmlinkage_protect(3, ret, rgid, egid, sgid);
103         return ret;
104 }
105
106 asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
107 {
108         const struct cred *cred = current_cred();
109         int retval;
110
111         if (!(retval   = put_user(high2lowgid(cred->gid),  rgid)) &&
112             !(retval   = put_user(high2lowgid(cred->egid), egid)))
113                 retval = put_user(high2lowgid(cred->sgid), sgid);
114
115         return retval;
116 }
117
118 asmlinkage long sys_setfsuid16(old_uid_t uid)
119 {
120         long ret = sys_setfsuid(low2highuid(uid));
121         /* avoid REGPARM breakage on x86: */
122         asmlinkage_protect(1, ret, uid);
123         return ret;
124 }
125
126 asmlinkage long sys_setfsgid16(old_gid_t gid)
127 {
128         long ret = sys_setfsgid(low2highgid(gid));
129         /* avoid REGPARM breakage on x86: */
130         asmlinkage_protect(1, ret, gid);
131         return ret;
132 }
133
134 static int groups16_to_user(old_gid_t __user *grouplist,
135     struct group_info *group_info)
136 {
137         int i;
138         old_gid_t group;
139
140         for (i = 0; i < group_info->ngroups; i++) {
141                 group = high2lowgid(GROUP_AT(group_info, i));
142                 if (put_user(group, grouplist+i))
143                         return -EFAULT;
144         }
145
146         return 0;
147 }
148
149 static int groups16_from_user(struct group_info *group_info,
150     old_gid_t __user *grouplist)
151 {
152         int i;
153         old_gid_t group;
154
155         for (i = 0; i < group_info->ngroups; i++) {
156                 if (get_user(group, grouplist+i))
157                         return  -EFAULT;
158                 GROUP_AT(group_info, i) = low2highgid(group);
159         }
160
161         return 0;
162 }
163
164 asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
165 {
166         const struct cred *cred = current_cred();
167         int i;
168
169         if (gidsetsize < 0)
170                 return -EINVAL;
171
172         i = cred->group_info->ngroups;
173         if (gidsetsize) {
174                 if (i > gidsetsize) {
175                         i = -EINVAL;
176                         goto out;
177                 }
178                 if (groups16_to_user(grouplist, cred->group_info)) {
179                         i = -EFAULT;
180                         goto out;
181                 }
182         }
183 out:
184         return i;
185 }
186
187 asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
188 {
189         struct group_info *group_info;
190         int retval;
191
192         if (!capable(CAP_SETGID))
193                 return -EPERM;
194         if ((unsigned)gidsetsize > NGROUPS_MAX)
195                 return -EINVAL;
196
197         group_info = groups_alloc(gidsetsize);
198         if (!group_info)
199                 return -ENOMEM;
200         retval = groups16_from_user(group_info, grouplist);
201         if (retval) {
202                 put_group_info(group_info);
203                 return retval;
204         }
205
206         retval = set_current_groups(group_info);
207         put_group_info(group_info);
208
209         return retval;
210 }
211
212 asmlinkage long sys_getuid16(void)
213 {
214         return high2lowuid(current_uid());
215 }
216
217 asmlinkage long sys_geteuid16(void)
218 {
219         return high2lowuid(current_euid());
220 }
221
222 asmlinkage long sys_getgid16(void)
223 {
224         return high2lowgid(current_gid());
225 }
226
227 asmlinkage long sys_getegid16(void)
228 {
229         return high2lowgid(current_egid());
230 }