From c801c4e1ba695ba230e97f626abaeb0c16393b09 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 2 Nov 2017 00:59:05 -0700 Subject: [PATCH 093/241] x86/entry/64: Use POP instead of MOV to restore regs on NMI return MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CVE-2017-5754 This gets rid of the last user of the old RESTORE_..._REGS infrastructure. Signed-off-by: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/652a260f17a160789bc6a41d997f98249b73e2ab.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar (cherry picked from commit 471ee4832209e986029b9fabdaad57b1eecb856b) Signed-off-by: Andy Whitcroft Signed-off-by: Kleber Sacilotto de Souza (cherry picked from commit 3c5771a43d8f00e53081871027fea891a091ff5e) Signed-off-by: Fabian Grünbichler --- arch/x86/entry/entry_64.S | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 87be1cd1fa88..4eff3aca54ed 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1572,11 +1572,14 @@ end_repeat_nmi: nmi_swapgs: SWAPGS_UNSAFE_STACK nmi_restore: - RESTORE_EXTRA_REGS - RESTORE_C_REGS + POP_EXTRA_REGS + POP_C_REGS - /* Point RSP at the "iret" frame. */ - REMOVE_PT_GPREGS_FROM_STACK 6*8 + /* + * Skip orig_ax and the "outermost" frame to point RSP at the "iret" + * at the "iret" frame. + */ + addq $6*8, %rsp /* * Clear "NMI executing". Set DF first so that we can easily -- 2.14.2