x86/bugs: Flush IBP in ib_prctl_set()

commit a664ec9158 upstream.

We missed the window between the TIF flag update and the next reschedule.

Signed-off-by: Rodrigo Branco <bsdaemon@google.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Rodrigo Branco 2023-01-03 14:17:51 -06:00 committed by Greg Kroah-Hartman
parent ba780bff9f
commit 8cbd7f2643

View file

@ -1787,6 +1787,8 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl)
if (ctrl == PR_SPEC_FORCE_DISABLE)
task_set_spec_ib_force_disable(task);
task_update_spec_tif(task);
if (task == current)
indirect_branch_prediction_barrier();
break;
default:
return -ERANGE;