[CVE-2009-0029] System call wrappers part 18
[linux-2.6.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 SYSCALL_DEFINE2(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 SYSCALL_DEFINE1(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 SYSCALL_DEFINE2(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 SYSCALL_DEFINE1(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 SYSCALL_DEFINE3(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 SYSCALL_DEFINE3(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 SYSCALL_DEFINE3(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
107 SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgid, old_gid_t __user *, egid, old_gid_t __user *, sgid)
108 {
109         const struct cred *cred = current_cred();
110         int retval;
111
112         if (!(retval   = put_user(high2lowgid(cred->gid),  rgid)) &&
113             !(retval   = put_user(high2lowgid(cred->egid), egid)))
114                 retval = put_user(high2lowgid(cred->sgid), sgid);
115
116         return retval;
117 }
118
119 SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)
120 {
121         long ret = sys_setfsuid(low2highuid(uid));
122         /* avoid REGPARM breakage on x86: */
123         asmlinkage_protect(1, ret, uid);
124         return ret;
125 }
126
127 SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
128 {
129         long ret = sys_setfsgid(low2highgid(gid));
130         /* avoid REGPARM breakage on x86: */
131         asmlinkage_protect(1, ret, gid);
132         return ret;
133 }
134
135 static int groups16_to_user(old_gid_t __user *grouplist,
136     struct group_info *group_info)
137 {
138         int i;
139         old_gid_t group;
140
141         for (i = 0; i < group_info->ngroups; i++) {
142                 group = high2lowgid(GROUP_AT(group_info, i));
143                 if (put_user(group, grouplist+i))
144                         return -EFAULT;
145         }
146
147         return 0;
148 }
149
150 static int groups16_from_user(struct group_info *group_info,
151     old_gid_t __user *grouplist)
152 {
153         int i;
154         old_gid_t group;
155
156         for (i = 0; i < group_info->ngroups; i++) {
157                 if (get_user(group, grouplist+i))
158                         return  -EFAULT;
159                 GROUP_AT(group_info, i) = low2highgid(group);
160         }
161
162         return 0;
163 }
164
165 asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
166 {
167         const struct cred *cred = current_cred();
168         int i;
169
170         if (gidsetsize < 0)
171                 return -EINVAL;
172
173         i = cred->group_info->ngroups;
174         if (gidsetsize) {
175                 if (i > gidsetsize) {
176                         i = -EINVAL;
177                         goto out;
178                 }
179                 if (groups16_to_user(grouplist, cred->group_info)) {
180                         i = -EFAULT;
181                         goto out;
182                 }
183         }
184 out:
185         return i;
186 }
187
188 asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
189 {
190         struct group_info *group_info;
191         int retval;
192
193         if (!capable(CAP_SETGID))
194                 return -EPERM;
195         if ((unsigned)gidsetsize > NGROUPS_MAX)
196                 return -EINVAL;
197
198         group_info = groups_alloc(gidsetsize);
199         if (!group_info)
200                 return -ENOMEM;
201         retval = groups16_from_user(group_info, grouplist);
202         if (retval) {
203                 put_group_info(group_info);
204                 return retval;
205         }
206
207         retval = set_current_groups(group_info);
208         put_group_info(group_info);
209
210         return retval;
211 }
212
213 asmlinkage long sys_getuid16(void)
214 {
215         return high2lowuid(current_uid());
216 }
217
218 asmlinkage long sys_geteuid16(void)
219 {
220         return high2lowuid(current_euid());
221 }
222
223 asmlinkage long sys_getgid16(void)
224 {
225         return high2lowgid(current_gid());
226 }
227
228 asmlinkage long sys_getegid16(void)
229 {
230         return high2lowgid(current_egid());
231 }