#include <linux/hw_breakpoint.h>
#include <linux/cn_proc.h>
#include <linux/compat.h>
+#include <linux/sched/signal.h>
/*
* Access another process' address space via ptrace.
*/
static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
{
- rcu_read_lock();
- __ptrace_link(child, new_parent, __task_cred(new_parent));
- rcu_read_unlock();
+ __ptrace_link(child, new_parent, current_cred());
}
/**
return -EPERM;
ok:
rcu_read_unlock();
+ /*
+ * If a task drops privileges and becomes nondumpable (through a syscall
+ * like setresuid()) while we are trying to access it, we must ensure
+ * that the dumpability is read after the credentials; otherwise,
+ * we may be able to attach to a task that we shouldn't be able to
+ * attach to (as if the task had dropped privileges without becoming
+ * nondumpable).
+ * Pairs with a write barrier in commit_creds().
+ */
+ smp_rmb();
mm = task->mm;
if (mm &&
((get_dumpable(mm) != SUID_DUMP_USER) &&
if (arg.nr < 0)
return -EINVAL;
+ /* Ensure arg.off fits in an unsigned long */
+ if (arg.off > ULONG_MAX)
+ return 0;
+
if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
pending = &child->signal->shared_pending;
else
for (i = 0; i < arg.nr; ) {
siginfo_t info;
- s32 off = arg.off + i;
+ unsigned long off = arg.off + i;
+ bool found = false;
spin_lock_irq(&child->sighand->siglock);
list_for_each_entry(q, &pending->list, list) {
if (!off--) {
+ found = true;
copy_siginfo(&info, &q->info);
break;
}
}
spin_unlock_irq(&child->sighand->siglock);
- if (off >= 0) /* beyond the end of the list */
+ if (!found) /* beyond the end of the list */
break;
#ifdef CONFIG_COMPAT
ret = ptrace_setsiginfo(child, &siginfo);
break;
- case PTRACE_GETSIGMASK:
+ case PTRACE_GETSIGMASK: {
+ sigset_t *mask;
+
if (addr != sizeof(sigset_t)) {
ret = -EINVAL;
break;
}
- if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
+ if (test_tsk_restore_sigmask(child))
+ mask = &child->saved_sigmask;
+ else
+ mask = &child->blocked;
+
+ if (copy_to_user(datavp, mask, sizeof(sigset_t)))
ret = -EFAULT;
else
ret = 0;
break;
+ }
case PTRACE_SETSIGMASK: {
sigset_t new_set;
child->blocked = new_set;
spin_unlock_irq(&child->sighand->siglock);
+ clear_tsk_restore_sigmask(child);
+
ret = 0;
break;
}