[PATCH] VMCI: Fix potential NULL pointer dereference when acquire a lock

[Xiyu Yang]

A NULL pointer can be returned by vmci_ctx_get(). Thus add a
corresponding check so that a NULL pointer dereference will
be avoided when acquire a lock in spin_lock.

Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>
---
 drivers/misc/vmw_vmci/vmci_context.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/misc/vmw_vmci/vmci_context.c b/drivers/misc/vmw_vmci/vmci_context.c
index 16695366ec92..a20878fba374 100644
--- a/drivers/misc/vmw_vmci/vmci_context.c
+++ b/drivers/misc/vmw_vmci/vmci_context.c
@@ -898,6 +898,8 @@ void vmci_ctx_rcv_notifications_release(u32 context_id,
 					bool success)
 {
 	struct vmci_ctx *context = vmci_ctx_get(context_id);
+	if (context == NULL)
+		return;
 
 	spin_lock(&context->lock);
 	if (!success) {
-- 
2.7.4