avcodec/hevcdec: check ff_init_cabac_decoder() for failure

Fixes: runtime error: left shift of 1965559808 by 4 places cannot be represented in type 'int'
Fixes: 2333/clusterfuzz-testcase-minimized-5223935677300736

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/hevc_cabac.c

@@ -467,12 +467,12 @@ static void cabac_reinit(HEVCLocalContext *lc)
     skip_bytes(&lc->cc, 0);
 }
 
-static void cabac_init_decoder(HEVCContext *s)
+static int cabac_init_decoder(HEVCContext *s)
 {
     GetBitContext *gb = &s->HEVClc->gb;
     skip_bits(gb, 1);
     align_get_bits(gb);
-    ff_init_cabac_decoder(&s->HEVClc->cc,
+    return ff_init_cabac_decoder(&s->HEVClc->cc,
                           gb->buffer + get_bits_count(gb) / 8,
                           (get_bits_left(gb) + 7) / 8);
 }
@@ -501,10 +501,12 @@ static void cabac_init_state(HEVCContext *s)
         s->HEVClc->stat_coeff[i] = 0;
 }
 
-void ff_hevc_cabac_init(HEVCContext *s, int ctb_addr_ts)
+int ff_hevc_cabac_init(HEVCContext *s, int ctb_addr_ts)
 {
     if (ctb_addr_ts == s->ps.pps->ctb_addr_rs_to_ts[s->sh.slice_ctb_addr_rs]) {
-        cabac_init_decoder(s);
+        int ret = cabac_init_decoder(s);
+        if (ret < 0)
+            return ret;
         if (s->sh.dependent_slice_segment_flag == 0 ||
             (s->ps.pps->tiles_enabled_flag &&
              s->ps.pps->tile_id[ctb_addr_ts] != s->ps.pps->tile_id[ctb_addr_ts - 1]))
@@ -524,8 +526,11 @@ void ff_hevc_cabac_init(HEVCContext *s, int ctb_addr_ts)
             s->ps.pps->tile_id[ctb_addr_ts] != s->ps.pps->tile_id[ctb_addr_ts - 1]) {
             if (s->threads_number == 1)
                 cabac_reinit(s->HEVClc);
-            else
-                cabac_init_decoder(s);
+            else {
+                int ret = cabac_init_decoder(s);
+                if (ret < 0)
+                    return ret;
+            }
             cabac_init_state(s);
         }
         if (s->ps.pps->entropy_coding_sync_enabled_flag) {
@@ -533,8 +538,11 @@ void ff_hevc_cabac_init(HEVCContext *s, int ctb_addr_ts)
                 get_cabac_terminate(&s->HEVClc->cc);
                 if (s->threads_number == 1)
                     cabac_reinit(s->HEVClc);
-                else
-                    cabac_init_decoder(s);
+                else {
+                    int ret = cabac_init_decoder(s);
+                    if (ret < 0)
+                        return ret;
+                }
 
                 if (s->ps.sps->ctb_width == 1)
                     cabac_init_state(s);
@@ -543,6 +551,7 @@ void ff_hevc_cabac_init(HEVCContext *s, int ctb_addr_ts)
             }
         }
     }
+    return 0;
 }
 
 #define GET_CABAC(ctx) get_cabac(&s->HEVClc->cc, &s->HEVClc->cabac_state[ctx])

libavcodec/hevcdec.c

@@ -2337,6 +2337,7 @@ static int hls_decode_entry(AVCodecContext *avctxt, void *isFilterThread)
     int x_ctb       = 0;
     int y_ctb       = 0;
     int ctb_addr_ts = s->ps.pps->ctb_addr_rs_to_ts[s->sh.slice_ctb_addr_rs];
+    int ret;
 
     if (!ctb_addr_ts && s->sh.dependent_slice_segment_flag) {
         av_log(s->avctx, AV_LOG_ERROR, "Impossible initial tile.\n");
@@ -2358,7 +2359,11 @@ static int hls_decode_entry(AVCodecContext *avctxt, void *isFilterThread)
         y_ctb = (ctb_addr_rs / ((s->ps.sps->width + ctb_size - 1) >> s->ps.sps->log2_ctb_size)) << s->ps.sps->log2_ctb_size;
         hls_decode_neighbour(s, x_ctb, y_ctb, ctb_addr_ts);
 
-        ff_hevc_cabac_init(s, ctb_addr_ts);
+        ret = ff_hevc_cabac_init(s, ctb_addr_ts);
+        if (ret < 0) {
+            s->tab_slice_address[ctb_addr_rs] = -1;
+            return ret;
+        }
 
         hls_sao_param(s, x_ctb >> s->ps.sps->log2_ctb_size, y_ctb >> s->ps.sps->log2_ctb_size);
 
@@ -2417,7 +2422,9 @@ static int hls_decode_entry_wpp(AVCodecContext *avctxt, void *input_ctb_row, int
 
         if (ret < 0)
             return ret;
-        ff_init_cabac_decoder(&lc->cc, s->data + s->sh.offset[(ctb_row)-1], s->sh.size[ctb_row - 1]);
+        ret = ff_init_cabac_decoder(&lc->cc, s->data + s->sh.offset[(ctb_row)-1], s->sh.size[ctb_row - 1]);
+        if (ret < 0)
+            goto error;
     }
 
     while(more_data && ctb_addr_ts < s->ps.sps->ctb_size) {
@@ -2433,15 +2440,15 @@ static int hls_decode_entry_wpp(AVCodecContext *avctxt, void *input_ctb_row, int
             return 0;
         }
 
-        ff_hevc_cabac_init(s, ctb_addr_ts);
+        ret = ff_hevc_cabac_init(s, ctb_addr_ts);
+        if (ret < 0)
+            goto error;
         hls_sao_param(s, x_ctb >> s->ps.sps->log2_ctb_size, y_ctb >> s->ps.sps->log2_ctb_size);
         more_data = hls_coding_quadtree(s, x_ctb, y_ctb, s->ps.sps->log2_ctb_size, 0);
 
         if (more_data < 0) {
-            s->tab_slice_address[ctb_addr_rs] = -1;
-            atomic_store(&s1->wpp_err, 1);
-            ff_thread_report_progress2(s->avctx, ctb_row ,thread, SHIFT_CTB_WPP);
-            return more_data;
+            ret = more_data;
+            goto error;
         }
 
         ctb_addr_ts++;
@@ -2471,6 +2478,11 @@ static int hls_decode_entry_wpp(AVCodecContext *avctxt, void *input_ctb_row, int
     ff_thread_report_progress2(s->avctx, ctb_row ,thread, SHIFT_CTB_WPP);
 
     return 0;
+error:
+    s->tab_slice_address[ctb_addr_rs] = -1;
+    atomic_store(&s1->wpp_err, 1);
+    ff_thread_report_progress2(s->avctx, ctb_row ,thread, SHIFT_CTB_WPP);
+    return ret;
 }
 
 static int hls_slice_data_wpp(HEVCContext *s, const H2645NAL *nal)

libavcodec/hevcdec.h

@@ -508,7 +508,7 @@ int ff_hevc_frame_rps(HEVCContext *s);
 int ff_hevc_slice_rpl(HEVCContext *s);
 
 void ff_hevc_save_states(HEVCContext *s, int ctb_addr_ts);
-void ff_hevc_cabac_init(HEVCContext *s, int ctb_addr_ts);
+int ff_hevc_cabac_init(HEVCContext *s, int ctb_addr_ts);
 int ff_hevc_sao_merge_flag_decode(HEVCContext *s);
 int ff_hevc_sao_type_idx_decode(HEVCContext *s);
 int ff_hevc_sao_band_position_decode(HEVCContext *s);