* [PATCH][next] KVM: x86/mmu: Fix uninitialized boolean variable flush
@ 2021-06-22 15:09 Colin King
2021-06-22 16:38 ` Sean Christopherson
2021-06-22 16:43 ` Paolo Bonzini
0 siblings, 2 replies; 3+ messages in thread
From: Colin King @ 2021-06-22 15:09 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li,
Jim Mattson, Joerg Roedel, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, x86, H . Peter Anvin, Ben Gardon, kvm
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
In the case where kvm_memslots_have_rmaps(kvm) is false the boolean
variable flush is not set and is uninitialized. If is_tdp_mmu_enabled(kvm)
is true then the call to kvm_tdp_mmu_zap_collapsible_sptes passes the
uninitialized value of flush into the call. Fix this by initializing
flush to false.
Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: e2209710ccc5 ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
arch/x86/kvm/mmu/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index ed24e97c1549..b8d20f139729 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5689,7 +5689,7 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
{
/* FIXME: const-ify all uses of struct kvm_memory_slot. */
struct kvm_memory_slot *slot = (struct kvm_memory_slot *)memslot;
- bool flush;
+ bool flush = false;
if (kvm_memslots_have_rmaps(kvm)) {
write_lock(&kvm->mmu_lock);
--
2.31.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH][next] KVM: x86/mmu: Fix uninitialized boolean variable flush
2021-06-22 15:09 [PATCH][next] KVM: x86/mmu: Fix uninitialized boolean variable flush Colin King
@ 2021-06-22 16:38 ` Sean Christopherson
2021-06-22 16:43 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Sean Christopherson @ 2021-06-22 16:38 UTC (permalink / raw)
To: Colin King
Cc: Paolo Bonzini, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
H . Peter Anvin, Ben Gardon, kvm, kernel-janitors, linux-kernel
On Tue, Jun 22, 2021, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> In the case where kvm_memslots_have_rmaps(kvm) is false the boolean
> variable flush is not set and is uninitialized. If is_tdp_mmu_enabled(kvm)
> is true then the call to kvm_tdp_mmu_zap_collapsible_sptes passes the
> uninitialized value of flush into the call. Fix this by initializing
> flush to false.
>
> Addresses-Coverity: ("Uninitialized scalar variable")
> Fixes: e2209710ccc5 ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
Reviewed-by: Sean Christopherson <seanjc@google.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH][next] KVM: x86/mmu: Fix uninitialized boolean variable flush
2021-06-22 15:09 [PATCH][next] KVM: x86/mmu: Fix uninitialized boolean variable flush Colin King
2021-06-22 16:38 ` Sean Christopherson
@ 2021-06-22 16:43 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2021-06-22 16:43 UTC (permalink / raw)
To: Colin King, Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li,
Jim Mattson, Joerg Roedel, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, x86, H . Peter Anvin, Ben Gardon, kvm
Cc: kernel-janitors, linux-kernel
On 22/06/21 17:09, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> In the case where kvm_memslots_have_rmaps(kvm) is false the boolean
> variable flush is not set and is uninitialized. If is_tdp_mmu_enabled(kvm)
> is true then the call to kvm_tdp_mmu_zap_collapsible_sptes passes the
> uninitialized value of flush into the call. Fix this by initializing
> flush to false.
>
> Addresses-Coverity: ("Uninitialized scalar variable")
> Fixes: e2209710ccc5 ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> arch/x86/kvm/mmu/mmu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index ed24e97c1549..b8d20f139729 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -5689,7 +5689,7 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
> {
> /* FIXME: const-ify all uses of struct kvm_memory_slot. */
> struct kvm_memory_slot *slot = (struct kvm_memory_slot *)memslot;
> - bool flush;
> + bool flush = false;
>
> if (kvm_memslots_have_rmaps(kvm)) {
> write_lock(&kvm->mmu_lock);
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
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