msm: camera: icp: Protect icp context access at time of pagefault

Take mutex before acessing icp context to prevent improper free.

Change-Id: If2fd2c66dd9a00f1ab5c9ec1710573c2921dce6a
Signed-off-by: Prakasha Nayak <[email protected]>

drivers/cam_icp/cam_icp_context.c

@@ -37,6 +37,14 @@ static int cam_icp_context_dump_active_request(void *data, unsigned long iova,
 		return -EINVAL;
 	}
 
+	mutex_lock(&ctx->ctx_mutex);
+
+	if (ctx->state < CAM_CTX_ACQUIRED || ctx->state > CAM_CTX_ACTIVATED) {
+		CAM_ERR(CAM_ICP, "Invalid state icp ctx %d state %d",
+			ctx->ctx_id, ctx->state);
+		goto end;
+	}
+
 	CAM_INFO(CAM_ICP, "iommu fault for icp ctx %d state %d",
 		ctx->ctx_id, ctx->state);
 
@@ -55,6 +63,8 @@ static int cam_icp_context_dump_active_request(void *data, unsigned long iova,
 				req->request_id, rc);
 	}
 
+end:
+	mutex_unlock(&ctx->ctx_mutex);
 	return rc;
 }