[PATCH] remoteproc: harden rproc_handle_vdev() against integer overflow

[Dan Carpenter <dan.carpenter@oracle.com>]

The struct_size() macro protects against integer overflows but adding
"+ rsc->config_len" introduces the risk of integer overflows again.
Use size_add() to be safe.

Fixes: c87846571587 ("remoteproc: use struct_size() helper")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/remoteproc/remoteproc_core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index e5279ed9a8d7..4fc5ce2187ac 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -520,12 +520,13 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
 	struct fw_rsc_vdev *rsc = ptr;
 	struct device *dev = &rproc->dev;
 	struct rproc_vdev *rvdev;
+	size_t rsc_size;
 	int i, ret;
 	char name[16];
 
 	/* make sure resource isn't truncated */
-	if (struct_size(rsc, vring, rsc->num_of_vrings) + rsc->config_len >
-			avail) {
+	rsc_size = struct_size(rsc, vring, rsc->num_of_vrings);
+	if (size_add(rsc_size, rsc->config_len) > avail) {
 		dev_err(dev, "vdev rsc is truncated\n");
 		return -EINVAL;
 	}
-- 
2.35.1