}
/*
+ * called with RCU read lock from check_kill_permission()
+ */
+static int kill_ok_by_cred(struct task_struct *t)
+{
+ const struct cred *cred = current_cred();
+ const struct cred *tcred = __task_cred(t);
+
+ if (cred->user->user_ns == tcred->user->user_ns &&
+ (cred->euid == tcred->suid ||
+ cred->euid == tcred->uid ||
+ cred->uid == tcred->suid ||
+ cred->uid == tcred->uid))
+ return 1;
+
+ if (ns_capable(tcred->user->user_ns, CAP_KILL))
+ return 1;
+
+ return 0;
+}
+
+/*
* Bad permissions for sending the signal
* - the caller must hold the RCU read lock
*/
static int check_kill_permission(int sig, struct siginfo *info,
struct task_struct *t)
{
- const struct cred *cred, *tcred;
struct pid *sid;
int error;
if (error)
return error;
- cred = current_cred();
- tcred = __task_cred(t);
if (!same_thread_group(current, t) &&
- (cred->euid ^ tcred->suid) &&
- (cred->euid ^ tcred->uid) &&
- (cred->uid ^ tcred->suid) &&
- (cred->uid ^ tcred->uid) &&
- !capable(CAP_KILL)) {
+ !kill_ok_by_cred(t)) {
switch (sig) {
case SIGCONT:
sid = task_session(t);