[PATCH 03/19] nitro_enclaves: Ignore the reply of a failed slot info command

[Alexander Graf <graf@amazon.com>]

When the nitro_enclaves device fails a SLOT_INFO command,
ne_event_work_handler() logs the failure and still compares the
enclave's state against the reply, which then holds zero or the reply
for the previous enclave. Zero is NE_STATE_INIT, so a running enclave is
recorded as not started: its owner is woken for a state change that did
not happen, and NE_ADD_VCPU, NE_SET_USER_MEMORY_REGION and
NE_START_ENCLAVE become callable on it again.

Skip the enclave when SLOT_INFO fails, so that it stays in
NE_STATE_RUNNING and a later event can examine it.

Fixes: e5d616d8bb50 ("nitro_enclaves: Handle out-of-band PCI device events")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Graf <graf@amazon.com>
---
 drivers/virt/nitro_enclaves/ne_pci_dev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/virt/nitro_enclaves/ne_pci_dev.c b/drivers/virt/nitro_enclaves/ne_pci_dev.c
index 3e1455d505269..c37777bb95b49 100644
--- a/drivers/virt/nitro_enclaves/ne_pci_dev.c
+++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c
@@ -243,9 +243,12 @@ static void ne_event_work_handler(struct work_struct *work)
 		rc = ne_do_request(pdev, SLOT_INFO,
 				   &slot_info_req, sizeof(slot_info_req),
 				   &cmd_reply, sizeof(cmd_reply));
-		if (rc < 0)
+		if (rc < 0) {
 			dev_err(&pdev->dev, "Error in slot info [rc=%d]\n", rc);
 
+			goto unlock;
+		}
+
 		/* Notify enclave process that the enclave state changed. */
 		if (ne_enclave->state != cmd_reply.state) {
 			ne_enclave->state = cmd_reply.state;
-- 
2.47.1