Re: ACK: [PATCH] efi/efi_test: Prevent an Oops in efi_runtime_query_capsulecaps()

[Matt Fleming <matt@codeblueprint.co.uk>]

On Wed, 11 Oct, at 02:26:57PM, Ivan Hu wrote:
> 
> 
> On 10/06/2017 08:19 PM, Matt Fleming wrote:
> >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.carpenter@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?
> >
> 
> 
> Acked-by: Ivan Hu <ivan.hu@canonical.com>

Thanks, applied.