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Subject[PATCH] x86/kvm/vmx: Fix GPF on reading vmentry_l1d_flush
Date

When EPT is not enabled, reading
/sys/module/kvm_intel/parameters/vmentry_l1d_flush causes
general protection fault in vmentry_l1d_flush_get() due to
access beyond the end of the array vmentry_l1d_param[].

Signed-off-by: Minoura Makoto <minoura@valinux.co.jp>
---
arch/x86/include/asm/vmx.h | 1 +
arch/x86/kvm/vmx.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 95f9107449bf..c4b834b05178 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -581,6 +581,7 @@ enum vmx_l1d_flush_state {
VMENTER_L1D_FLUSH_NEVER,
VMENTER_L1D_FLUSH_COND,
VMENTER_L1D_FLUSH_ALWAYS,
+ VMENTER_L1D_FLUSH_PARAM_MAX = VMENTER_L1D_FLUSH_ALWAYS,
VMENTER_L1D_FLUSH_EPT_DISABLED,
VMENTER_L1D_FLUSH_NOT_REQUIRED,
};
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1519f030fd73..155ba2a9139f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -204,6 +204,8 @@ static const struct {
{"never", VMENTER_L1D_FLUSH_NEVER},
{"cond", VMENTER_L1D_FLUSH_COND},
{"always", VMENTER_L1D_FLUSH_ALWAYS},
+ {"ept-disabled", VMENTER_L1D_FLUSH_EPT_DISABLED},
+ {"not-required", VMENTER_L1D_FLUSH_NOT_REQUIRED},
};

#define L1D_CACHE_ORDER 4
@@ -286,7 +288,7 @@ static int vmentry_l1d_flush_parse(const char *s)
unsigned int i;

if (s) {
- for (i = 0; i < ARRAY_SIZE(vmentry_l1d_param); i++) {
+ for (i = 0; i <= VMENTER_L1D_FLUSH_PARAM_MAX; i++) {
if (sysfs_streq(s, vmentry_l1d_param[i].option))
return vmentry_l1d_param[i].cmd;
}
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