Commit 3d788b2f authored by Rick Edgecombe's avatar Rick Edgecombe Committed by Wei Liu

uio_hv_generic: Don't free decrypted memory

In CoCo VMs it is possible for the untrusted host to cause
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.

The VMBus device UIO driver could free decrypted/shared pages if
set_memory_decrypted() fails. Check the decrypted field in the gpadl
to decide whether to free the memory.
Signed-off-by: default avatarRick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: default avatarMichael Kelley <mhklinux@outlook.com>
Reviewed-by: default avatarKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20240311161558.1310-5-mhklinux@outlook.comSigned-off-by: default avatarWei Liu <wei.liu@kernel.org>
Message-ID: <20240311161558.1310-5-mhklinux@outlook.com>
parent bbf9ac34
...@@ -181,12 +181,14 @@ hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata) ...@@ -181,12 +181,14 @@ hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata)
{ {
if (pdata->send_gpadl.gpadl_handle) { if (pdata->send_gpadl.gpadl_handle) {
vmbus_teardown_gpadl(dev->channel, &pdata->send_gpadl); 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) { if (pdata->recv_gpadl.gpadl_handle) {
vmbus_teardown_gpadl(dev->channel, &pdata->recv_gpadl); 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, ...@@ -295,7 +297,8 @@ hv_uio_probe(struct hv_device *dev,
ret = vmbus_establish_gpadl(channel, pdata->recv_buf, ret = vmbus_establish_gpadl(channel, pdata->recv_buf,
RECV_BUFFER_SIZE, &pdata->recv_gpadl); RECV_BUFFER_SIZE, &pdata->recv_gpadl);
if (ret) { if (ret) {
vfree(pdata->recv_buf); if (!pdata->recv_gpadl.decrypted)
vfree(pdata->recv_buf);
goto fail_close; goto fail_close;
} }
...@@ -317,7 +320,8 @@ hv_uio_probe(struct hv_device *dev, ...@@ -317,7 +320,8 @@ hv_uio_probe(struct hv_device *dev,
ret = vmbus_establish_gpadl(channel, pdata->send_buf, ret = vmbus_establish_gpadl(channel, pdata->send_buf,
SEND_BUFFER_SIZE, &pdata->send_gpadl); SEND_BUFFER_SIZE, &pdata->send_gpadl);
if (ret) { if (ret) {
vfree(pdata->send_buf); if (!pdata->send_gpadl.decrypted)
vfree(pdata->send_buf);
goto fail_close; goto fail_close;
} }
......
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