Add a range check for cpi->gf_frame_index

This gives an error for frame_parallel_level array out-of-bounds
access.

Bug: b/468491090

Change-Id: Iebed5d0c689c9fc614708a873f46f8ed9bc11050

av1/av1_cx_iface.c

diff --git a/av1/av1_cx_iface.c b/av1/av1_cx_iface.c
index 603fe1b..b2e03fa 100644
--- a/av1/av1_cx_iface.c
+++ b/av1/av1_cx_iface.c
@@ -3577,6 +3577,13 @@
 
 #endif  // CONFIG_FPMT_TEST
       if (!simulate_parallel_frame) {
+        // Add a range check here to give an error for frame_parallel_level
+        // array out-of-bounds access.
+        if (cpi->gf_frame_index >= MAX_STATIC_GF_GROUP_LENGTH) {
+          aom_internal_error(&ppi->error, AOM_CODEC_ERROR,
+                             "cpi->gf_frame_index is out of range");
+        }
+
         // May need a better way for checking the frame's frame_parallel_level,
         // especially for the first frame of the following gop.
         if (ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] == 0) {