diff mbox series

[1/2] KVM: arm64: Fix off-by-one in range_is_memory

Message ID 20210728153232.1018911-2-dbrazdil@google.com (mailing list archive)
State New, archived
Headers show
Series Fix off-by-one in range_is_memory | expand

Commit Message

David Brazdil July 28, 2021, 3:32 p.m. UTC
Hyp checks whether an address range only covers RAM by checking the
start/endpoints against a list of memblock_region structs. However,
the endpoint here is exclusive but internally is treated as inclusive.
Fix the off-by-one error that caused valid address ranges to be
rejected.

Cc: Quentin Perret <qperret@google.com>
Fixes: 90134ac9cabb6 ("KVM: arm64: Protect the .hyp sections from the host")
Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/kvm/hyp/nvhe/mem_protect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Quentin Perret July 29, 2021, 4:52 p.m. UTC | #1
On Wednesday 28 Jul 2021 at 15:32:31 (+0000), David Brazdil wrote:
> Hyp checks whether an address range only covers RAM by checking the
> start/endpoints against a list of memblock_region structs. However,
> the endpoint here is exclusive but internally is treated as inclusive.
> Fix the off-by-one error that caused valid address ranges to be
> rejected.
> 
> Cc: Quentin Perret <qperret@google.com>
> Fixes: 90134ac9cabb6 ("KVM: arm64: Protect the .hyp sections from the host")
> Signed-off-by: David Brazdil <dbrazdil@google.com>
> ---
>  arch/arm64/kvm/hyp/nvhe/mem_protect.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> index d938ce95d3bd..a6ce991b1467 100644
> --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
> @@ -193,7 +193,7 @@ static bool range_is_memory(u64 start, u64 end)
>  {
>  	struct kvm_mem_range r1, r2;
>  
> -	if (!find_mem_range(start, &r1) || !find_mem_range(end, &r2))
> +	if (!find_mem_range(start, &r1) || !find_mem_range(end - 1, &r2))
>  		return false;
>  	if (r1.start != r2.start)
>  		return false;

Looks good to me:

Reviewed-by: Quentin Perret <qperret@google.com>

Thanks,
Quentin
diff mbox series

Patch

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index d938ce95d3bd..a6ce991b1467 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -193,7 +193,7 @@  static bool range_is_memory(u64 start, u64 end)
 {
 	struct kvm_mem_range r1, r2;
 
-	if (!find_mem_range(start, &r1) || !find_mem_range(end, &r2))
+	if (!find_mem_range(start, &r1) || !find_mem_range(end - 1, &r2))
 		return false;
 	if (r1.start != r2.start)
 		return false;