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 asmlinkage long sys_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 asmlinkage long sys_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 asmlinkage long sys_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 }