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vmx: add missing entries in the l1d_param array

PATCH Paolo Bonzini 1 participant 2 messages Aug 22, 2018 1 message not in the archive KVM

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Paolo Bonzini

author maintainer Applied
#1 lore raw
Quoted 33 lines · Bandan Das

This can cause a host crash if an access attempts
to reach the missing entry. Future-proof the get
function against any overflows as well.

Signed-off-by Bandan Das <[email protected]>
---
 arch/x86/kvm/vmx.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)
arch/x86/kvm/vmx.c +6 -1
index 46b428c0990e..42c27406b63e 100644
@@ -203,6 +203,8 @@ static const struct {
 	{"never",	VMENTER_L1D_FLUSH_NEVER},
 	{"cond",	VMENTER_L1D_FLUSH_COND},
 	{"always",	VMENTER_L1D_FLUSH_ALWAYS},
+	{"disabled",    VMENTER_L1D_FLUSH_EPT_DISABLED},
+	{"not required", VMENTER_L1D_FLUSH_NOT_REQUIRED},
 };
 
 #define L1D_CACHE_ORDER 4

@@ -323,7 +325,17 @@ static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp)
 
 static int vmentry_l1d_flush_get(char *s, const struct kernel_param *kp)
 {
-	return sprintf(s, "%s\n", vmentry_l1d_param[l1tf_vmx_mitigation].option);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(vmentry_l1d_param); i++) {
+		if (vmentry_l1d_param[i].cmd == l1tf_vmx_mitigation)

arch/x86/kvm/vmx.c static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp) · line 341

Quoted 10 lines
arch/x86/kvm/vmx.c +7 -0
+			break;
+	}
+
+	if (i == ARRAY_SIZE(vmentry_l1d_param))
+		return -EINVAL;
+
+	return sprintf(s, "%s\n", vmentry_l1d_param[i].option);
 }
 
 static const struct kernel_param_ops vmentry_l1d_flush_ops = {

Queued, thanks.

Paolo

author maintainer
#2 lore raw
In reply to a message not in the archive
Quoted 33 lines · Bandan Das

This can cause a host crash if an access attempts
to reach the missing entry. Future-proof the get
function against any overflows as well.

Signed-off-by Bandan Das <[email protected]>
---
 arch/x86/kvm/vmx.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)
arch/x86/kvm/vmx.c +6 -1
index 46b428c0990e..42c27406b63e 100644
@@ -203,6 +203,8 @@ static const struct {
 	{"never",	VMENTER_L1D_FLUSH_NEVER},
 	{"cond",	VMENTER_L1D_FLUSH_COND},
 	{"always",	VMENTER_L1D_FLUSH_ALWAYS},
+	{"disabled",    VMENTER_L1D_FLUSH_EPT_DISABLED},
+	{"not required", VMENTER_L1D_FLUSH_NOT_REQUIRED},
 };
 
 #define L1D_CACHE_ORDER 4

@@ -323,7 +325,17 @@ static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp)
 
 static int vmentry_l1d_flush_get(char *s, const struct kernel_param *kp)
 {
-	return sprintf(s, "%s\n", vmentry_l1d_param[l1tf_vmx_mitigation].option);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(vmentry_l1d_param); i++) {
+		if (vmentry_l1d_param[i].cmd == l1tf_vmx_mitigation)

arch/x86/kvm/vmx.c static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp) · line 341

Quoted 10 lines
arch/x86/kvm/vmx.c +7 -0
+			break;
+	}
+
+	if (i == ARRAY_SIZE(vmentry_l1d_param))
+		return -EINVAL;
+
+	return sprintf(s, "%s\n", vmentry_l1d_param[i].option);
 }
 
 static const struct kernel_param_ops vmentry_l1d_flush_ops = {

Hmm, actually the two missing entries must be rejected by vmentry_l1d_flush_parse. I've fixed up the patch since I'm going to send a pull request to Linus today.

Paolo