libavcodec/msgsmdec.c:36: error: Integer Overflow L2
  (32 - [0, 64]):unsigned32 by call to `gsm_decode_block`.

libavcodec/msgsmdec.c:35:5: Call
33.     int res;
34.     BitstreamContext bc;
35.     bitstream_init(&bc, buf, GSM_MS_BLOCK_SIZE * 8);
        ^
36.     res = gsm_decode_block(avctx, samples, &bc, mode);
37.     if (res < 0)

libavcodec/bitstream.h:85:9: Assignment
  83.         bc->buffer    =
  84.         bc->ptr       = NULL;
  85.         bc->bits_left = 0;
              ^
  86.         return AVERROR_INVALIDDATA;
  87.     }

libavcodec/msgsmdec.c:36:11: Call
34.     BitstreamContext bc;
35.     bitstream_init(&bc, buf, GSM_MS_BLOCK_SIZE * 8);
36.     res = gsm_decode_block(avctx, samples, &bc, mode);
              ^
37.     if (res < 0)
38.         return res;

libavcodec/gsmdec_template.c:122:1: Parameter `bc->bits_left`
  120. }
  121. 
  122. static int gsm_decode_block(AVCodecContext *avctx, int16_t *samples,
       ^
  123.                             BitstreamContext *bc, int mode)
  124. {

libavcodec/gsmdec_template.c:129:30: Call
  127.     int16_t *ref_dst = ctx->ref_buf + 120;
  128.     int *lar = ctx->lar[ctx->lar_idx];
  129.     lar[0] = decode_log_area(bitstream_read(bc, 6), 13107,  1 << 15);
                                    ^
  130.     lar[1] = decode_log_area(bitstream_read(bc, 6), 13107,  1 << 15);
  131.     lar[2] = decode_log_area(bitstream_read(bc, 5), 13107, (1 << 14) + 2048 * 2);

libavcodec/bitstream.h:183:1: Parameter `n`
    181. 
    182. /* Return n bits from the buffer. n has to be in the 0-32 range. */
    183. static inline uint32_t bitstream_read(BitstreamContext *bc, unsigned n)
         ^
    184. {
    185.     if (!n)

libavcodec/bitstream.h:189:9: Call
    187. 
    188.     if (n > bc->bits_left) {
    189.         refill_32(bc);
                 ^
    190.         if (bc->bits_left < 32)
    191.             bc->bits_left = n;

libavcodec/bitstream.h:60:1: <RHS trace>
58. }
59. 
60. static inline void refill_32(BitstreamContext *bc)
    ^
61. {
62.     if (bc->ptr >= bc->buffer_end)

libavcodec/bitstream.h:60:1: Parameter `bc->bits_left`
      58. }
      59. 
      60. static inline void refill_32(BitstreamContext *bc)
          ^
      61. {
      62.     if (bc->ptr >= bc->buffer_end)

libavcodec/bitstream.h:68:5: Binary operation: (32 - [0, 64]):unsigned32 by call to `gsm_decode_block` 
      66.     bc->bits       = (uint64_t)AV_RL32(bc->ptr) << bc->bits_left | bc->bits;
      67. #else
      68.     bc->bits       = bc->bits | (uint64_t)AV_RB32(bc->ptr) << (32 - bc->bits_left);
              ^
      69. #endif
      70.     bc->ptr       += 4;
