linux-hardened/kernel/uid16.c
Eric W. Biederman a29c33f4e5 userns: Convert setting and getting uid and gid system calls to use kuid and kgid
Convert setregid, setgid, setreuid, setuid,
setresuid, getresuid, setresgid, getresgid, setfsuid, setfsgid,
getuid, geteuid, getgid, getegid,
waitpid, waitid, wait4.

Convert userspace uids and gids into kuids and kgids before
being placed on struct cred.  Convert struct cred kuids and
kgids into userspace uids and gids when returning them.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-03 03:28:41 -07:00

250 lines
6 KiB
C

/*
* Wrapper functions for 16bit uid back compatibility. All nicely tied
* together in the faint hope we can take the out in five years time.
*/
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/prctl.h>
#include <linux/capability.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>
SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
{
long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(3, ret, filename, user, group);
return ret;
}
SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
{
long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(3, ret, filename, user, group);
return ret;
}
SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
{
long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(3, ret, fd, user, group);
return ret;
}
SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)
{
long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(2, ret, rgid, egid);
return ret;
}
SYSCALL_DEFINE1(setgid16, old_gid_t, gid)
{
long ret = sys_setgid(low2highgid(gid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(1, ret, gid);
return ret;
}
SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)
{
long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(2, ret, ruid, euid);
return ret;
}
SYSCALL_DEFINE1(setuid16, old_uid_t, uid)
{
long ret = sys_setuid(low2highuid(uid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(1, ret, uid);
return ret;
}
SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)
{
long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
low2highuid(suid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(3, ret, ruid, euid, suid);
return ret;
}
SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruidp, old_uid_t __user *, euidp, old_uid_t __user *, suidp)
{
const struct cred *cred = current_cred();
int retval;
old_uid_t ruid, euid, suid;
ruid = high2lowuid(from_kuid_munged(cred->user_ns, cred->uid));
euid = high2lowuid(from_kuid_munged(cred->user_ns, cred->euid));
suid = high2lowuid(from_kuid_munged(cred->user_ns, cred->suid));
if (!(retval = put_user(ruid, ruidp)) &&
!(retval = put_user(euid, euidp)))
retval = put_user(suid, suidp);
return retval;
}
SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid)
{
long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
low2highgid(sgid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(3, ret, rgid, egid, sgid);
return ret;
}
SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgidp, old_gid_t __user *, egidp, old_gid_t __user *, sgidp)
{
const struct cred *cred = current_cred();
int retval;
old_gid_t rgid, egid, sgid;
rgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->gid));
egid = high2lowgid(from_kgid_munged(cred->user_ns, cred->egid));
sgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->sgid));
if (!(retval = put_user(rgid, rgidp)) &&
!(retval = put_user(egid, egidp)))
retval = put_user(sgid, sgidp);
return retval;
}
SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)
{
long ret = sys_setfsuid(low2highuid(uid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(1, ret, uid);
return ret;
}
SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
{
long ret = sys_setfsgid(low2highgid(gid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(1, ret, gid);
return ret;
}
static int groups16_to_user(old_gid_t __user *grouplist,
struct group_info *group_info)
{
struct user_namespace *user_ns = current_user_ns();
int i;
old_gid_t group;
kgid_t kgid;
for (i = 0; i < group_info->ngroups; i++) {
kgid = GROUP_AT(group_info, i);
group = high2lowgid(from_kgid_munged(user_ns, kgid));
if (put_user(group, grouplist+i))
return -EFAULT;
}
return 0;
}
static int groups16_from_user(struct group_info *group_info,
old_gid_t __user *grouplist)
{
struct user_namespace *user_ns = current_user_ns();
int i;
old_gid_t group;
kgid_t kgid;
for (i = 0; i < group_info->ngroups; i++) {
if (get_user(group, grouplist+i))
return -EFAULT;
kgid = make_kgid(user_ns, low2highgid(group));
if (!gid_valid(kgid))
return -EINVAL;
GROUP_AT(group_info, i) = kgid;
}
return 0;
}
SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
{
const struct cred *cred = current_cred();
int i;
if (gidsetsize < 0)
return -EINVAL;
i = cred->group_info->ngroups;
if (gidsetsize) {
if (i > gidsetsize) {
i = -EINVAL;
goto out;
}
if (groups16_to_user(grouplist, cred->group_info)) {
i = -EFAULT;
goto out;
}
}
out:
return i;
}
SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
{
struct group_info *group_info;
int retval;
if (!nsown_capable(CAP_SETGID))
return -EPERM;
if ((unsigned)gidsetsize > NGROUPS_MAX)
return -EINVAL;
group_info = groups_alloc(gidsetsize);
if (!group_info)
return -ENOMEM;
retval = groups16_from_user(group_info, grouplist);
if (retval) {
put_group_info(group_info);
return retval;
}
retval = set_current_groups(group_info);
put_group_info(group_info);
return retval;
}
SYSCALL_DEFINE0(getuid16)
{
return high2lowuid(from_kuid_munged(current_user_ns(), current_uid()));
}
SYSCALL_DEFINE0(geteuid16)
{
return high2lowuid(from_kuid_munged(current_user_ns(), current_euid()));
}
SYSCALL_DEFINE0(getgid16)
{
return high2lowgid(from_kgid_munged(current_user_ns(), current_gid()));
}
SYSCALL_DEFINE0(getegid16)
{
return high2lowgid(from_kgid_munged(current_user_ns(), current_egid()));
}