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 SYSCALL_DEFINE2(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 SYSCALL_DEFINE2(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 SYSCALL_DEFINE0(getuid16)
 214 {
 215         return high2lowuid(current_uid());
 216 }
 217
 218 SYSCALL_DEFINE0(geteuid16)
 219 {
 220         return high2lowuid(current_euid());
 221 }
 222
 223 SYSCALL_DEFINE0(getgid16)
 224 {
 225         return high2lowgid(current_gid());
 226 }
 227
 228 SYSCALL_DEFINE0(getegid16)
 229 {
 230         return high2lowgid(current_egid());
 231 }