Merge tag 'x86_urgent_for_v6.1_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Do not hold fpregs lock when inheriting FPU permissions because the
   fpregs lock disables preemption on RT but fpu_inherit_perms() does
   spin_lock_irq(), which, on RT, uses rtmutexes and they need to be
   preemptible.

 - Check the page offset and the length of the data supplied by
   userspace for overflow when specifying a set of pages to add to an
   SGX enclave

* tag 'x86_urgent_for_v6.1_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Drop fpregs lock before inheriting FPU permissions
  x86/sgx: Add overflow check in sgx_validate_offset_length()

Author: torvalds

arch/x86/kernel/cpu/sgx/ioctl.c

@@ -356,6 +356,9 @@ static int sgx_validate_offset_length(struct sgx_encl *encl,
 	if (!length || !IS_ALIGNED(length, PAGE_SIZE))
 		return -EINVAL;
 
+	if (offset + length < offset)
+		return -EINVAL;
+
 	if (offset + length - PAGE_SIZE >= encl->size)
 		return -EINVAL;
 

arch/x86/kernel/fpu/core.c

@@ -605,9 +605,9 @@ int fpu_clone(struct task_struct *dst, unsigned long clone_flags, bool minimal)
 	if (test_thread_flag(TIF_NEED_FPU_LOAD))
 		fpregs_restore_userregs();
 	save_fpregs_to_fpstate(dst_fpu);
+	fpregs_unlock();
 	if (!(clone_flags & CLONE_THREAD))
 		fpu_inherit_perms(dst_fpu);
-	fpregs_unlock();
 
 	/*
 	 * Children never inherit PASID state.