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/mman.h>
   8 #include <linux/notifier.h>
   9 #include <linux/reboot.h>
  10 #include <linux/prctl.h>
  11 #include <linux/capability.h>
  12 #include <linux/init.h>
  13 #include <linux/highuid.h>
  14 #include <linux/security.h>
  15 #include <linux/syscalls.h>
  16
  17 #include <asm/uaccess.h>
  18
  19 SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
  20 {
  21         long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
  22         /* avoid REGPARM breakage on x86: */
  23         asmlinkage_protect(3, ret, filename, user, group);
  24         return ret;
  25 }
  26
  27 SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
  28 {
  29         long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
  30         /* avoid REGPARM breakage on x86: */
  31         asmlinkage_protect(3, ret, filename, user, group);
  32         return ret;
  33 }
  34
  35 SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
  36 {
  37         long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
  38         /* avoid REGPARM breakage on x86: */
  39         asmlinkage_protect(3, ret, fd, user, group);
  40         return ret;
  41 }
  42
  43 SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)
  44 {
  45         long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
  46         /* avoid REGPARM breakage on x86: */
  47         asmlinkage_protect(2, ret, rgid, egid);
  48         return ret;
  49 }
  50
  51 SYSCALL_DEFINE1(setgid16, old_gid_t, gid)
  52 {
  53         long ret = sys_setgid(low2highgid(gid));
  54         /* avoid REGPARM breakage on x86: */
  55         asmlinkage_protect(1, ret, gid);
  56         return ret;
  57 }
  58
  59 SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)
  60 {
  61         long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
  62         /* avoid REGPARM breakage on x86: */
  63         asmlinkage_protect(2, ret, ruid, euid);
  64         return ret;
  65 }
  66
  67 SYSCALL_DEFINE1(setuid16, old_uid_t, uid)
  68 {
  69         long ret = sys_setuid(low2highuid(uid));
  70         /* avoid REGPARM breakage on x86: */
  71         asmlinkage_protect(1, ret, uid);
  72         return ret;
  73 }
  74
  75 SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)
  76 {
  77         long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
  78                                  low2highuid(suid));
  79         /* avoid REGPARM breakage on x86: */
  80         asmlinkage_protect(3, ret, ruid, euid, suid);
  81         return ret;
  82 }
  83
  84 SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruid, old_uid_t __user *, euid, old_uid_t __user *, suid)
  85 {
  86         const struct cred *cred = current_cred();
  87         int retval;
  88
  89         if (!(retval   = put_user(high2lowuid(cred->uid),  ruid)) &&
  90             !(retval   = put_user(high2lowuid(cred->euid), euid)))
  91                 retval = put_user(high2lowuid(cred->suid), suid);
  92
  93         return retval;
  94 }
  95
  96 SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid)
  97 {
  98         long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
  99                                  low2highgid(sgid));
 100         /* avoid REGPARM breakage on x86: */
 101         asmlinkage_protect(3, ret, rgid, egid, sgid);
 102         return ret;
 103 }
 104
 105
 106 SYSCALL_DEFINE3(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 SYSCALL_DEFINE1(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 SYSCALL_DEFINE1(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 SYSCALL_DEFINE2(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 SYSCALL_DEFINE2(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 SYSCALL_DEFINE0(getuid16)
 213 {
 214         return high2lowuid(current_uid());
 215 }
 216
 217 SYSCALL_DEFINE0(geteuid16)
 218 {
 219         return high2lowuid(current_euid());
 220 }
 221
 222 SYSCALL_DEFINE0(getgid16)
 223 {
 224         return high2lowgid(current_gid());
 225 }
 226
 227 SYSCALL_DEFINE0(getegid16)
 228 {
 229         return high2lowgid(current_egid());
 230 }