iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: x86: Protect ioapic_write_indirect() from Spectre-v1/L1TF attacks

Browse Source 
commit 670564559c upstream.

This fixes a Spectre-v1/L1TF vulnerability in ioapic_write_indirect().
This function contains index computations based on the
(attacker-controlled) IOREGSEL register.

This patch depends on patch
"KVM: x86: Protect ioapic_read_indirect() from Spectre-v1/L1TF attacks".

Fixes: 70f93dae32 ("KVM: Use temporary variable to shorten lines.")

Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Marios Pomonis
2019-12-11 12:47:45 -08:00
committed by Greg Kroah-Hartman
parent 9bffdc7b11
commit 6367499bd6
1 changed files with 2 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/kvm/ioapic.c
View File

@ -36,6 +36,7 @@
#include <linux/io.h> #include <linux/io.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/export.h> #include <linux/export.h>
#include <linux/nospec.h>
#include <asm/processor.h> #include <asm/processor.h>
#include <asm/page.h> #include <asm/page.h>
#include <asm/current.h> #include <asm/current.h>
@ -299,6 +300,7 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
ioapic_debug("change redir index %x val %x\n", index, val); ioapic_debug("change redir index %x val %x\n", index, val);
if (index >= IOAPIC_NUM_PINS) if (index >= IOAPIC_NUM_PINS)
return; return;
index = array_index_nospec(index, IOAPIC_NUM_PINS);
e = &ioapic->redirtbl[index]; e = &ioapic->redirtbl[index];
mask_before = e->fields.mask; mask_before = e->fields.mask;
/* Preserve read-only fields */ /* Preserve read-only fields */