| From 3f6f1480d86bf9fc16c160d803ab1d006e3058d5 Mon Sep 17 00:00:00 2001 |
| From: Nadav Amit <namit@cs.technion.ac.il> |
| Date: Mon, 13 Oct 2014 13:04:14 +0300 |
| Subject: KVM: x86: PREFETCH and HINT_NOP should have SrcMem flag |
| |
| From: Nadav Amit <namit@cs.technion.ac.il> |
| |
| commit 3f6f1480d86bf9fc16c160d803ab1d006e3058d5 upstream. |
| |
| The decode phase of the x86 emulator assumes that every instruction with the |
| ModRM flag, and which can be used with RIP-relative addressing, has either |
| SrcMem or DstMem. This is not the case for several instructions - prefetch, |
| hint-nop and clflush. |
| |
| Adding SrcMem|NoAccess for prefetch and hint-nop and SrcMem for clflush. |
| |
| This fixes CVE-2014-8480. |
| |
| Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5 |
| Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> |
| Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/x86/kvm/emulate.c | 7 ++++--- |
| 1 file changed, 4 insertions(+), 3 deletions(-) |
| |
| --- a/arch/x86/kvm/emulate.c |
| +++ b/arch/x86/kvm/emulate.c |
| @@ -3715,7 +3715,7 @@ static const struct opcode group11[] = { |
| }; |
| |
| static const struct gprefix pfx_0f_ae_7 = { |
| - I(0, em_clflush), N, N, N, |
| + I(SrcMem | ByteOp, em_clflush), N, N, N, |
| }; |
| |
| static const struct group_dual group15 = { { |
| @@ -3928,10 +3928,11 @@ static const struct opcode twobyte_table |
| N, I(ImplicitOps | EmulateOnUD, em_syscall), |
| II(ImplicitOps | Priv, em_clts, clts), N, |
| DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N, |
| - N, D(ImplicitOps | ModRM), N, N, |
| + N, D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N, |
| /* 0x10 - 0x1F */ |
| N, N, N, N, N, N, N, N, |
| - D(ImplicitOps | ModRM), N, N, N, N, N, N, D(ImplicitOps | ModRM), |
| + D(ImplicitOps | ModRM | SrcMem | NoAccess), |
| + N, N, N, N, N, N, D(ImplicitOps | ModRM | SrcMem | NoAccess), |
| /* 0x20 - 0x2F */ |
| DIP(ModRM | DstMem | Priv | Op3264 | NoMod, cr_read, check_cr_read), |
| DIP(ModRM | DstMem | Priv | Op3264 | NoMod, dr_read, check_dr_read), |
