2023-11-02 18:17:05

by Philipp Stanner

Subject: [PATCH 2/3] arch/s390/kvm: copy userspace-array safely

guestdbg.c utilizes memdup_user() to copy a userspace array. This,
currently, does not check for an overflow.

Use the new wrapper memdup_array_user() to copy the array more safely.

Suggested-by: Dave Airlie <[email protected]>
Signed-off-by: Philipp Stanner <[email protected]>
---
arch/s390/kvm/guestdbg.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/kvm/guestdbg.c b/arch/s390/kvm/guestdbg.c
index 3765c4223bf9..80879fc73c90 100644
--- a/arch/s390/kvm/guestdbg.c
+++ b/arch/s390/kvm/guestdbg.c
@@ -213,8 +213,8 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu,
else if (dbg->arch.nr_hw_bp > MAX_BP_COUNT)
return -EINVAL;

- bp_data = memdup_user(dbg->arch.hw_bp,
- sizeof(*bp_data) * dbg->arch.nr_hw_bp);
+ bp_data = memdup_array_user(dbg->arch.hw_bp, dbg->arch.nr_hw_bp,
+ sizeof(*bp_data));
if (IS_ERR(bp_data))
return PTR_ERR(bp_data);

--
2.41.0

2023-11-03 12:01:54

by Claudio Imbrenda

Subject: Re: [PATCH 2/3] arch/s390/kvm: copy userspace-array safely

On Thu, 2 Nov 2023 19:15:25 +0100
Philipp Stanner <[email protected]> wrote:

> guestdbg.c utilizes memdup_user() to copy a userspace array. This,
> currently, does not check for an overflow.
>
> Use the new wrapper memdup_array_user() to copy the array more safely.
>
> Suggested-by: Dave Airlie <[email protected]>
> Signed-off-by: Philipp Stanner <[email protected]>

Acked-by: Claudio Imbrenda <[email protected]>

> ---
> arch/s390/kvm/guestdbg.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/s390/kvm/guestdbg.c b/arch/s390/kvm/guestdbg.c
> index 3765c4223bf9..80879fc73c90 100644
> --- a/arch/s390/kvm/guestdbg.c
> +++ b/arch/s390/kvm/guestdbg.c
> @@ -213,8 +213,8 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu,
> else if (dbg->arch.nr_hw_bp > MAX_BP_COUNT)
> return -EINVAL;
>
> - bp_data = memdup_user(dbg->arch.hw_bp,
> - sizeof(*bp_data) * dbg->arch.nr_hw_bp);
> + bp_data = memdup_array_user(dbg->arch.hw_bp, dbg->arch.nr_hw_bp,
> + sizeof(*bp_data));
> if (IS_ERR(bp_data))
> return PTR_ERR(bp_data);
>