Revision 0620fddb56dfaf0e1034eeb69d79c73b361debbf authored by Eric Biggers on 08 June 2017, 13:49:26 UTC, committed by James Morris on 09 June 2017, 03:29:48 UTC
While a 'struct key' itself normally does not contain sensitive information, Documentation/security/keys.txt actually encourages this: "Having a payload is not required; and the payload can, in fact, just be a value stored in the struct key itself." In case someone has taken this advice, or will take this advice in the future, zero the key structure before freeing it. We might as well, and as a bonus this could make it a bit more difficult for an adversary to determine which keys have recently been in use. This is safe because the key_jar cache does not use a constructor. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
1 parent ee618b4
uid16.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/cred.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
{
return sys_chown(filename, low2highuid(user), low2highgid(group));
}
SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
{
return sys_lchown(filename, low2highuid(user), low2highgid(group));
}
SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
{
return sys_fchown(fd, low2highuid(user), low2highgid(group));
}
SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)
{
return sys_setregid(low2highgid(rgid), low2highgid(egid));
}
SYSCALL_DEFINE1(setgid16, old_gid_t, gid)
{
return sys_setgid(low2highgid(gid));
}
SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)
{
return sys_setreuid(low2highuid(ruid), low2highuid(euid));
}
SYSCALL_DEFINE1(setuid16, old_uid_t, uid)
{
return sys_setuid(low2highuid(uid));
}
SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)
{
return sys_setresuid(low2highuid(ruid), low2highuid(euid),
low2highuid(suid));
}
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)
{
return sys_setresgid(low2highgid(rgid), low2highgid(egid),
low2highgid(sgid));
}
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)
{
return sys_setfsuid(low2highuid(uid));
}
SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
{
return sys_setfsgid(low2highgid(gid));
}
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_info->gid[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_info->gid[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 (!may_setgroups())
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()));
}
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