From: Rick Edgecombe <[email protected]> Sent: Wednesday, February 21, 2024 6:10 PM > > On TDX it is possible for the untrusted host to cause
Same comment about TDX vs. CoCo VM. > set_memory_encrypted() or set_memory_decrypted() to fail such that an > error is returned and the resulting memory is shared. Callers need to take > care to handle these errors to avoid returning decrypted (shared) memory to > the page allocator, which could lead to functional or security issues. > > uio_hv_generic could free decrypted/shared pages if > set_memory_decrypted() fails. > > Check the decrypted field in the gpadl before freeing in order to not > leak the memory. > > Only compile tested. > > Cc: "K. Y. Srinivasan" <[email protected]> > Cc: Haiyang Zhang <[email protected]> > Cc: Wei Liu <[email protected]> > Cc: Dexuan Cui <[email protected]> > Cc: [email protected] > Signed-off-by: Rick Edgecombe <[email protected]> > --- > drivers/uio/uio_hv_generic.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c > index 20d9762331bd..6be3462b109f 100644 > --- a/drivers/uio/uio_hv_generic.c > +++ b/drivers/uio/uio_hv_generic.c > @@ -181,12 +181,14 @@ hv_uio_cleanup(struct hv_device *dev, struct > hv_uio_private_data *pdata) > { > if (pdata->send_gpadl.gpadl_handle) { > vmbus_teardown_gpadl(dev->channel, &pdata->send_gpadl); > - vfree(pdata->send_buf); > + if (!pdata->send_gpadl.decrypted) > + vfree(pdata->send_buf); > } > > if (pdata->recv_gpadl.gpadl_handle) { > vmbus_teardown_gpadl(dev->channel, &pdata->recv_gpadl); > - vfree(pdata->recv_buf); > + if (!pdata->recv_gpadl.decrypted) > + vfree(pdata->recv_buf); > } > } > > @@ -295,7 +297,8 @@ hv_uio_probe(struct hv_device *dev, > ret = vmbus_establish_gpadl(channel, pdata->recv_buf, > RECV_BUFFER_SIZE, &pdata->recv_gpadl); > if (ret) { > - vfree(pdata->recv_buf); > + if (!pdata->recv_gpadl.decrypted) > + vfree(pdata->recv_buf); > goto fail_close; > } > > @@ -317,7 +320,8 @@ hv_uio_probe(struct hv_device *dev, > ret = vmbus_establish_gpadl(channel, pdata->send_buf, > SEND_BUFFER_SIZE, &pdata->send_gpadl); > if (ret) { > - vfree(pdata->send_buf); > + if (!pdata->send_gpadl.decrypted) > + vfree(pdata->send_buf); > goto fail_close; > } > > -- > 2.34.1
