diff --git a/vp9/common/vp9_onyxc_int.h b/vp9/common/vp9_onyxc_int.h
index f710f8106..188b03d41 100644
--- a/vp9/common/vp9_onyxc_int.h
+++ b/vp9/common/vp9_onyxc_int.h
@@ -14,6 +14,7 @@
 #include "./vpx_config.h"
 #include "vpx/internal/vpx_codec_internal.h"
 #include "./vp9_rtcd.h"
+#include "vp9/common/vp9_alloccommon.h"
 #include "vp9/common/vp9_loopfilter.h"
 #include "vp9/common/vp9_entropymv.h"
 #include "vp9/common/vp9_entropy.h"
@@ -307,8 +308,13 @@ static INLINE int get_free_fb(VP9_COMMON *cm) {
     if (frame_bufs[i].ref_count == 0)
       break;
 
-  assert(i < FRAME_BUFFERS);
-  frame_bufs[i].ref_count = 1;
+  if (i != FRAME_BUFFERS) {
+    frame_bufs[i].ref_count = 1;
+  } else {
+    // Reset i to be INVALID_IDX to indicate no free buffer found.
+    i = INVALID_IDX;
+  }
+
   unlock_buffer_pool(cm->buffer_pool);
   return i;
 }
diff --git a/vp9/decoder/vp9_decoder.c b/vp9/decoder/vp9_decoder.c
index cf1f23fb9..7991a39e6 100644
--- a/vp9/decoder/vp9_decoder.c
+++ b/vp9/decoder/vp9_decoder.c
@@ -211,6 +211,9 @@ vpx_codec_err_t vp9_set_reference_dec(VP9_COMMON *cm,
 
     // Find an empty frame buffer.
     const int free_fb = get_free_fb(cm);
+    if (cm->new_fb_idx == INVALID_IDX)
+      return VPX_CODEC_MEM_ERROR;
+
     // Decrease ref_count since it will be increased again in
     // ref_cnt_fb() below.
     --frame_bufs[free_fb].ref_count;
@@ -298,7 +301,10 @@ int vp9_receive_compressed_data(VP9Decoder *pbi,
       && frame_bufs[cm->new_fb_idx].ref_count == 0)
     pool->release_fb_cb(pool->cb_priv,
                         &frame_bufs[cm->new_fb_idx].raw_frame_buffer);
+  // Find a free frame buffer. Return error if can not find any.
   cm->new_fb_idx = get_free_fb(cm);
+  if (cm->new_fb_idx == INVALID_IDX)
+    return VPX_CODEC_MEM_ERROR;
 
   // Assign a MV array to the frame buffer.
   cm->cur_frame = &pool->frame_bufs[cm->new_fb_idx];
diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index 1f4288387..4a7561342 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -2714,7 +2714,10 @@ void vp9_scale_references(VP9_COMP *cpi) {
 #if CONFIG_VP9_HIGHBITDEPTH
       if (ref->y_crop_width != cm->width || ref->y_crop_height != cm->height) {
         const int new_fb = get_free_fb(cm);
-        RefCntBuffer *const new_fb_ptr = &pool->frame_bufs[new_fb];
+        RefCntBuffer *new_fb_ptr = NULL;
+        if (cm->new_fb_idx == INVALID_IDX)
+          return;
+        new_fb_ptr = &pool->frame_bufs[new_fb];
         cm->cur_frame = &pool->frame_bufs[new_fb];
         vp9_realloc_frame_buffer(&pool->frame_bufs[new_fb].buf,
                                  cm->width, cm->height,
@@ -2726,7 +2729,10 @@ void vp9_scale_references(VP9_COMP *cpi) {
 #else
       if (ref->y_crop_width != cm->width || ref->y_crop_height != cm->height) {
         const int new_fb = get_free_fb(cm);
-        RefCntBuffer *const new_fb_ptr = &pool->frame_bufs[new_fb];
+        RefCntBuffer *new_fb_ptr = NULL;
+        if (cm->new_fb_idx == INVALID_IDX)
+          return;
+        new_fb_ptr = &pool->frame_bufs[new_fb];
         vp9_realloc_frame_buffer(&new_fb_ptr->buf,
                                  cm->width, cm->height,
                                  cm->subsampling_x, cm->subsampling_y,