On Sat, 30 Sep, at 11:17:32AM, Dan Carpenter wrote:
> If "qcaps.capsule_count" is ULONG_MAX then "qcaps.capsule_count + 1"
> will overflow to zero and kcalloc() will return the ZERO_SIZE_PTR.  We
> try to dereference it inside the loop and crash.
> 
> Fixes: ff6301dabc3c ("efi: Add efi_test driver for exporting UEFI runtime 
> service interfaces")
> Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
> 
> diff --git a/drivers/firmware/efi/test/efi_test.c 
> b/drivers/firmware/efi/test/efi_test.c
> index 08129b7b80ab..41c48a1e8baa 100644
> --- a/drivers/firmware/efi/test/efi_test.c
> +++ b/drivers/firmware/efi/test/efi_test.c
> @@ -593,6 +593,9 @@ static long efi_runtime_query_capsulecaps(unsigned long 
> arg)
>       if (copy_from_user(&qcaps, qcaps_user, sizeof(qcaps)))
>               return -EFAULT;
>  
> +     if (qcaps.capsule_count == ULONG_MAX)
> +             return -EINVAL;
> +
>       capsules = kcalloc(qcaps.capsule_count + 1,
>                          sizeof(efi_capsule_header_t), GFP_KERNEL);
>       if (!capsules)

This looks OK to me. Ivan?
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