Source
x
usermodehelper_inheritable = cap_intersect(usermodehelper_inheritable, new_cap);
// SPDX-License-Identifier: GPL-2.0-only
/*
* umh - the kernel usermode helper
*/
static kernel_cap_t usermodehelper_bset = CAP_FULL_SET;
static kernel_cap_t usermodehelper_inheritable = CAP_FULL_SET;
static DEFINE_SPINLOCK(umh_sysctl_lock);
static DECLARE_RWSEM(umhelper_sem);
static LIST_HEAD(umh_list);
static DEFINE_MUTEX(umh_list_lock);
static void call_usermodehelper_freeinfo(struct subprocess_info *info)
{
if (info->cleanup)
(*info->cleanup)(info);
kfree(info);
}
static void umh_complete(struct subprocess_info *sub_info)
{
struct completion *comp = xchg(&sub_info->complete, NULL);
/*
* See call_usermodehelper_exec(). If xchg() returns NULL
* we own sub_info, the UMH_KILLABLE caller has gone away
* or the caller used UMH_NO_WAIT.
*/
if (comp)
complete(comp);
else
call_usermodehelper_freeinfo(sub_info);
}
/*
* This is the task which runs the usermode application
*/
static int call_usermodehelper_exec_async(void *data)
{
struct subprocess_info *sub_info = data;
struct cred *new;
int retval;
spin_lock_irq(¤t->sighand->siglock);
flush_signal_handlers(current, 1);
spin_unlock_irq(¤t->sighand->siglock);
/*
* Our parent (unbound workqueue) runs with elevated scheduling
* priority. Avoid propagating that into the userspace child.
*/
set_user_nice(current, 0);
retval = -ENOMEM;
new = prepare_kernel_cred(current);
if (!new)
goto out;
spin_lock(&umh_sysctl_lock);
new->cap_bset = cap_intersect(usermodehelper_bset, new->cap_bset);
new->cap_inheritable = cap_intersect(usermodehelper_inheritable,
new->cap_inheritable);