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/cred.h>
  16 #include <linux/syscalls.h>
  17
  18 #include <linux/uaccess.h>
  19
  20 SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
  21 {
  22         return sys_chown(filename, low2highuid(user), low2highgid(group));
  23 }
  24
  25 SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
  26 {
  27         return sys_lchown(filename, low2highuid(user), low2highgid(group));
  28 }
  29
  30 SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
  31 {
  32         return sys_fchown(fd, low2highuid(user), low2highgid(group));
  33 }
  34
  35 SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)
  36 {
  37         return sys_setregid(low2highgid(rgid), low2highgid(egid));
  38 }
  39
  40 SYSCALL_DEFINE1(setgid16, old_gid_t, gid)
  41 {
  42         return sys_setgid(low2highgid(gid));
  43 }
  44
  45 SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)
  46 {
  47         return sys_setreuid(low2highuid(ruid), low2highuid(euid));
  48 }
  49
  50 SYSCALL_DEFINE1(setuid16, old_uid_t, uid)
  51 {
  52         return sys_setuid(low2highuid(uid));
  53 }
  54
  55 SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)
  56 {
  57         return sys_setresuid(low2highuid(ruid), low2highuid(euid),
  58                                  low2highuid(suid));
  59 }
  60
  61 SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruidp, old_uid_t __user *, euidp, old_uid_t __user *, suidp)
  62 {
  63         const struct cred *cred = current_cred();
  64         int retval;
  65         old_uid_t ruid, euid, suid;
  66
  67         ruid = high2lowuid(from_kuid_munged(cred->user_ns, cred->uid));
  68         euid = high2lowuid(from_kuid_munged(cred->user_ns, cred->euid));
  69         suid = high2lowuid(from_kuid_munged(cred->user_ns, cred->suid));
  70
  71         if (!(retval   = put_user(ruid, ruidp)) &&
  72             !(retval   = put_user(euid, euidp)))
  73                 retval = put_user(suid, suidp);
  74
  75         return retval;
  76 }
  77
  78 SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid)
  79 {
  80         return sys_setresgid(low2highgid(rgid), low2highgid(egid),
  81                                  low2highgid(sgid));
  82 }
  83
  84
  85 SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgidp, old_gid_t __user *, egidp, old_gid_t __user *, sgidp)
  86 {
  87         const struct cred *cred = current_cred();
  88         int retval;
  89         old_gid_t rgid, egid, sgid;
  90
  91         rgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->gid));
  92         egid = high2lowgid(from_kgid_munged(cred->user_ns, cred->egid));
  93         sgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->sgid));
  94
  95         if (!(retval   = put_user(rgid, rgidp)) &&
  96             !(retval   = put_user(egid, egidp)))
  97                 retval = put_user(sgid, sgidp);
  98
  99         return retval;
 100 }
 101
 102 SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)
 103 {
 104         return sys_setfsuid(low2highuid(uid));
 105 }
 106
 107 SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
 108 {
 109         return sys_setfsgid(low2highgid(gid));
 110 }
 111
 112 static int groups16_to_user(old_gid_t __user *grouplist,
 113     struct group_info *group_info)
 114 {
 115         struct user_namespace *user_ns = current_user_ns();
 116         int i;
 117         old_gid_t group;
 118         kgid_t kgid;
 119
 120         for (i = 0; i < group_info->ngroups; i++) {
 121                 kgid = group_info->gid[i];
 122                 group = high2lowgid(from_kgid_munged(user_ns, kgid));
 123                 if (put_user(group, grouplist+i))
 124                         return -EFAULT;
 125         }
 126
 127         return 0;
 128 }
 129
 130 static int groups16_from_user(struct group_info *group_info,
 131     old_gid_t __user *grouplist)
 132 {
 133         struct user_namespace *user_ns = current_user_ns();
 134         int i;
 135         old_gid_t group;
 136         kgid_t kgid;
 137
 138         for (i = 0; i < group_info->ngroups; i++) {
 139                 if (get_user(group, grouplist+i))
 140                         return  -EFAULT;
 141
 142                 kgid = make_kgid(user_ns, low2highgid(group));
 143                 if (!gid_valid(kgid))
 144                         return -EINVAL;
 145
 146                 group_info->gid[i] = kgid;
 147         }
 148
 149         return 0;
 150 }
 151
 152 SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
 153 {
 154         const struct cred *cred = current_cred();
 155         int i;
 156
 157         if (gidsetsize < 0)
 158                 return -EINVAL;
 159
 160         i = cred->group_info->ngroups;
 161         if (gidsetsize) {
 162                 if (i > gidsetsize) {
 163                         i = -EINVAL;
 164                         goto out;
 165                 }
 166                 if (groups16_to_user(grouplist, cred->group_info)) {
 167                         i = -EFAULT;
 168                         goto out;
 169                 }
 170         }
 171 out:
 172         return i;
 173 }
 174
 175 SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
 176 {
 177         struct group_info *group_info;
 178         int retval;
 179
 180         if (!may_setgroups())
 181                 return -EPERM;
 182         if ((unsigned)gidsetsize > NGROUPS_MAX)
 183                 return -EINVAL;
 184
 185         group_info = groups_alloc(gidsetsize);
 186         if (!group_info)
 187                 return -ENOMEM;
 188         retval = groups16_from_user(group_info, grouplist);
 189         if (retval) {
 190                 put_group_info(group_info);
 191                 return retval;
 192         }
 193
 194         retval = set_current_groups(group_info);
 195         put_group_info(group_info);
 196
 197         return retval;
 198 }
 199
 200 SYSCALL_DEFINE0(getuid16)
 201 {
 202         return high2lowuid(from_kuid_munged(current_user_ns(), current_uid()));
 203 }
 204
 205 SYSCALL_DEFINE0(geteuid16)
 206 {
 207         return high2lowuid(from_kuid_munged(current_user_ns(), current_euid()));
 208 }
 209
 210 SYSCALL_DEFINE0(getgid16)
 211 {
 212         return high2lowgid(from_kgid_munged(current_user_ns(), current_gid()));
 213 }
 214
 215 SYSCALL_DEFINE0(getegid16)
 216 {
 217         return high2lowgid(from_kgid_munged(current_user_ns(), current_egid()));
 218 }