asmlinkage long sys_setfsgid16(old_gid_t gid)
{
long ret = sys_setfsgid(low2highgid(gid));
/* avoid REGPARM breakage on x86: */
asmlinkage_protect(1, ret, gid);
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;
}
asmlinkage long sys_setfsgid16(old_gid_t gid)
{
return sys_setfsgid((gid_t)gid);
}
asmlinkage long sys32_setfsgid16(u16 gid)
{
return sys_setfsgid((gid_t)gid);
}
static int restore_creds(CredsEntry *ce)
{
int b, i, ret;
struct cap_header hdr;
struct cap_data data[_LINUX_CAPABILITY_U32S_3];
/*
* We're still root here and thus can do it without failures.
*/
/*
* First -- set the SECURE_NO_SETUID_FIXUP bit not to
* lose caps bits when changing xids.
*/
ret = sys_prctl(PR_SET_SECUREBITS, 1 << SECURE_NO_SETUID_FIXUP, 0, 0, 0);
if (ret) {
pr_err("Unable to set SECURE_NO_SETUID_FIXUP: %d\n", ret);
return -1;
}
/*
* Second -- restore xids. Since we still have the CAP_SETUID
* capability nothing should fail. But call the setfsXid last
* to override the setresXid settings.
*/
ret = sys_setresuid(ce->uid, ce->euid, ce->suid);
if (ret) {
pr_err("Unable to set real, effective and saved user ID: %d\n", ret);
return -1;
}
sys_setfsuid(ce->fsuid);
if (sys_setfsuid(-1) != ce->fsuid) {
pr_err("Unable to set fsuid\n");
return -1;
}
ret = sys_setresgid(ce->gid, ce->egid, ce->sgid);
if (ret) {
pr_err("Unable to set real, effective and saved group ID: %d\n", ret);
return -1;
}
sys_setfsgid(ce->fsgid);
if (sys_setfsgid(-1) != ce->fsgid) {
pr_err("Unable to set fsgid\n");
return -1;
}
/*
* Third -- restore securebits. We don't need them in any
* special state any longer.
*/
ret = sys_prctl(PR_SET_SECUREBITS, ce->secbits, 0, 0, 0);
if (ret) {
pr_err("Unable to set PR_SET_SECUREBITS: %d\n", ret);
return -1;
}
/*
* Fourth -- trim bset. This can only be done while
* having the CAP_SETPCAP capablity.
*/
for (b = 0; b < CR_CAP_SIZE; b++) {
for (i = 0; i < 32; i++) {
if (b * 32 + i > cap_last_cap)
break;
if (ce->cap_bnd[b] & (1 << i))
/* already set */
continue;
ret = sys_prctl(PR_CAPBSET_DROP, i + b * 32, 0, 0, 0);
if (ret) {
pr_err("Unable to drop capability %d: %d\n",
i + b * 32, ret);
return -1;
}
}
}
/*
* Fifth -- restore caps. Nothing but cap bits are changed
* at this stage, so just do it.
*/
hdr.version = _LINUX_CAPABILITY_VERSION_3;
hdr.pid = 0;
BUILD_BUG_ON(_LINUX_CAPABILITY_U32S_3 != CR_CAP_SIZE);
for (i = 0; i < CR_CAP_SIZE; i++) {
data[i].eff = ce->cap_eff[i];
data[i].prm = ce->cap_prm[i];
data[i].inh = ce->cap_inh[i];
}
ret = sys_capset(&hdr, data);
if (ret) {
pr_err("Unable to restore capabilities: %d\n", ret);
return -1;
}
return 0;
}
