[PATCH] Drivers: hv: vmbus: Initialize unload_event statically
From: Andrea Parri (Microsoft)
Date: Fri Apr 16 2021 - 10:40:56 EST
If a malicious or compromised Hyper-V sends a spurious message of type
CHANNELMSG_UNLOAD_RESPONSE, the function vmbus_unload_response() will
call complete() on an uninitialized event, and cause an oops.
Reported-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
---
drivers/hv/channel_mgmt.c | 2 +-
drivers/hv/connection.c | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index f3cf4af01e102..1efb616480a64 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -841,7 +841,7 @@ void vmbus_initiate_unload(bool crash)
if (vmbus_proto_version < VERSION_WIN8_1)
return;
- init_completion(&vmbus_connection.unload_event);
+ reinit_completion(&vmbus_connection.unload_event);
memset(&hdr, 0, sizeof(struct vmbus_channel_message_header));
hdr.msgtype = CHANNELMSG_UNLOAD;
vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header),
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 350e8c5cafa8c..529dcc47f3e11 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -26,6 +26,8 @@
struct vmbus_connection vmbus_connection = {
.conn_state = DISCONNECTED,
+ .unload_event = COMPLETION_INITIALIZER(
+ vmbus_connection.unload_event),
.next_gpadl_handle = ATOMIC_INIT(0xE1E10),
.ready_for_suspend_event = COMPLETION_INITIALIZER(
--
2.25.1