index 28176f3..e299812 100644
--- a/libavcodec/vorbis.c
+++ b/libavcodec/vorbis.c
@@ -179,12 +179,14 @@ static inline void render_line_unrolled(intptr_t x, uint8_t y, int x1,
     }
 }

-static void render_line(int x0, uint8_t y0, int x1, int y1, float *buf)
+static int render_line(int x0, uint8_t y0, int x1, int y1, float *buf)
 {
     int dy  = y1 - y0;
     int adx = x1 - x0;
     int ady = FFABS(dy);
     int sy  = dy < 0 ? -1 : 1;
+    if (adx == 0)
+        return -1;
     buf[x0] = ff_vorbis_floor1_inverse_db_table[y0];
     if (ady*2 <= adx) { // optimized common case
         render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
@@ -204,9 +206,10 @@ static void render_line(int x0, uint8_t y0, int x1, int y1, float *buf)
             buf[x] = ff_vorbis_floor1_inverse_db_table[y];
         }
     }
+    return 0;
 }

-void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
+int ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
                                   uint16_t *y_list, int *flag,
                                   int multiplier, float *out, int samples)
 {
@@ -219,8 +222,8 @@ void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
         if (flag[pos]) {
             int x1 = list[pos].x;
             int y1 = y_list[pos] * multiplier;
-            if (lx < samples)
-                render_line(lx, ly, FFMIN(x1,samples), y1, out);
+            if (lx < samples && render_line(lx, ly, FFMIN(x1,samples), y1, out) < 0)
+                return -1;
             lx = x1;
             ly = y1;
         }
@@ -228,5 +231,7 @@ void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
             break;
     }
     if (lx < samples)
-        render_line(lx, ly, samples, ly, out);
+        if (render_line(lx, ly, samples, ly, out) == -1)
+            return -1;
+    return 0;
 }
diff --git a/libavcodec/vorbis.h b/libavcodec/vorbis.h
index cad080e..03b1f1b 100644
--- a/libavcodec/vorbis.h
+++ b/libavcodec/vorbis.h
@@ -39,7 +39,7 @@ typedef struct {
 void ff_vorbis_ready_floor1_list(vorbis_floor1_entry * list, int values);
 unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n); // x^(1/n)
 int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num);
-void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
+int ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
                                   uint16_t *y_list, int *flag,
                                   int multiplier, float * out, int samples);
 void vorbis_inverse_coupling(float *mag, float *ang, int blocksize);
diff --git a/libavcodec/vorbisdec.c b/libavcodec/vorbisdec.c
index 6bf785e..bd2dfd9 100644
--- a/libavcodec/vorbisdec.c
+++ b/libavcodec/vorbisdec.c
@@ -1270,7 +1270,9 @@ static int vorbis_floor1_decode(vorbis_context *vc,

 // Curve synth - connect the calculated dots and convert from dB scale FIXME optimize ?

-    ff_vorbis_floor1_render_list(vf->list, vf->x_list_dim, floor1_Y_final, floor1_flag, vf->multiplier, vec, vf->list[1].x);
+    if (ff_vorbis_floor1_render_list(vf->list, vf->x_list_dim, floor1_Y_final, floor1_flag, vf->multiplier, vec, vf->list[1].x) == -1)
+        return AVERROR_INVALIDDATA;
+

     av_dlog(NULL, " Floor decoded\n");