Messages in this thread | | | Date | Mon, 6 Nov 2023 13:50:11 +0100 | From | Claudio Imbrenda <> | Subject | Re: [PATCH v1 1/1] s390/uvdevice: Report additional-data length for attestation |
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On Mon, 6 Nov 2023 13:49:22 +0100 Steffen Eiden <seiden@linux.ibm.com> wrote:
> Additional data length in the attestation request is an in/out variable. > Software provides the capacity of the buffer. Upon successful request, > firmware reports the actual bytes written to the additional data in that > field. This information is lost, as the length field was not copied back > to userspace before. Attestation might fail, if user space did not > specify the exact amount of needed bytes required, as this length is > part of the attestation measurement. > > Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> --- > drivers/s390/char/uvdevice.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c > index 144cd2e03590..42c9f77f8da0 100644 > --- a/drivers/s390/char/uvdevice.c > +++ b/drivers/s390/char/uvdevice.c > @@ -109,6 +109,7 @@ static int uvio_copy_attest_result_to_user(struct uv_cb_attest *uvcb_attest, > struct uvio_attest *uvio_attest) > { > struct uvio_attest __user *user_uvio_attest = (void __user *)uv_ioctl->argument_addr; > + u32 __user *user_buf_add_len = (u32 __user *)&user_uvio_attest->add_data_len; > void __user *user_buf_add = (void __user *)uvio_attest->add_data_addr; > void __user *user_buf_meas = (void __user *)uvio_attest->meas_addr; > void __user *user_buf_uid = &user_uvio_attest->config_uid; > @@ -117,6 +118,8 @@ static int uvio_copy_attest_result_to_user(struct uv_cb_attest *uvcb_attest, > return -EFAULT; > if (add_data && copy_to_user(user_buf_add, add_data, uvio_attest->add_data_len)) > return -EFAULT; > + if (put_user(uvio_attest->add_data_len, user_buf_add_len)) > + return -EFAULT; > if (copy_to_user(user_buf_uid, uvcb_attest->config_uid, sizeof(uvcb_attest->config_uid))) > return -EFAULT; > return 0;
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