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         int retval;
  88
  89         if (!(retval = put_user(high2lowuid(current->uid), ruid)) &&
  90             !(retval = put_user(high2lowuid(current->euid), euid)))
  91                 retval = put_user(high2lowuid(current->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         int retval;
 109
 110         if (!(retval = put_user(high2lowgid(current->gid), rgid)) &&
 111             !(retval = put_user(high2lowgid(current->egid), egid)))
 112                 retval = put_user(high2lowgid(current->sgid), sgid);
 113
 114         return retval;
 115 }
 116
 117 SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)
 118 {
 119         long ret = sys_setfsuid(low2highuid(uid));
 120         /* avoid REGPARM breakage on x86: */
 121         asmlinkage_protect(1, ret, uid);
 122         return ret;
 123 }
 124
 125 SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
 126 {
 127         long ret = sys_setfsgid(low2highgid(gid));
 128         /* avoid REGPARM breakage on x86: */
 129         asmlinkage_protect(1, ret, gid);
 130         return ret;
 131 }
 132
 133 static int groups16_to_user(old_gid_t __user *grouplist,
 134     struct group_info *group_info)
 135 {
 136         int i;
 137         old_gid_t group;
 138
 139         for (i = 0; i < group_info->ngroups; i++) {
 140                 group = high2lowgid(GROUP_AT(group_info, i));
 141                 if (put_user(group, grouplist+i))
 142                         return -EFAULT;
 143         }
 144
 145         return 0;
 146 }
 147
 148 static int groups16_from_user(struct group_info *group_info,
 149     old_gid_t __user *grouplist)
 150 {
 151         int i;
 152         old_gid_t group;
 153
 154         for (i = 0; i < group_info->ngroups; i++) {
 155                 if (get_user(group, grouplist+i))
 156                         return  -EFAULT;
 157                 GROUP_AT(group_info, i) = low2highgid(group);
 158         }
 159
 160         return 0;
 161 }
 162
 163 SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
 164 {
 165         int i = 0;
 166
 167         if (gidsetsize < 0)
 168                 return -EINVAL;
 169
 170         get_group_info(current->group_info);
 171         i = current->group_info->ngroups;
 172         if (gidsetsize) {
 173                 if (i > gidsetsize) {
 174                         i = -EINVAL;
 175                         goto out;
 176                 }
 177                 if (groups16_to_user(grouplist, current->group_info)) {
 178                         i = -EFAULT;
 179                         goto out;
 180                 }
 181         }
 182 out:
 183         put_group_info(current->group_info);
 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 }