libavcodec/smacker.c:287: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 285 could be null and is dereferenced by call to `get_bits1()` at line 287, column 9.

libavcodec/smacker.c:276:1: start of procedure decode_header_trees()
274. }
275. 
276. static int decode_header_trees(SmackVContext *smk) {
     ^
277.     GetBitContext gb;
278.     int mmap_size, mclr_size, full_size, type_size;

libavcodec/smacker.c:280:5: 
278.     int mmap_size, mclr_size, full_size, type_size;
279. 
280.     mmap_size = AV_RL32(smk->avctx->extradata);
         ^
281.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
282.     full_size = AV_RL32(smk->avctx->extradata + 8);

libavcodec/smacker.c:281:5: 
279. 
280.     mmap_size = AV_RL32(smk->avctx->extradata);
281.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
         ^
282.     full_size = AV_RL32(smk->avctx->extradata + 8);
283.     type_size = AV_RL32(smk->avctx->extradata + 12);

libavcodec/smacker.c:282:5: 
280.     mmap_size = AV_RL32(smk->avctx->extradata);
281.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
282.     full_size = AV_RL32(smk->avctx->extradata + 8);
         ^
283.     type_size = AV_RL32(smk->avctx->extradata + 12);
284. 

libavcodec/smacker.c:283:5: 
281.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
282.     full_size = AV_RL32(smk->avctx->extradata + 8);
283.     type_size = AV_RL32(smk->avctx->extradata + 12);
         ^
284. 
285.     init_get_bits(&gb, smk->avctx->extradata + 16, (smk->avctx->extradata_size - 16) * 8);

libavcodec/smacker.c:285:5: 
283.     type_size = AV_RL32(smk->avctx->extradata + 12);
284. 
285.     init_get_bits(&gb, smk->avctx->extradata + 16, (smk->avctx->extradata_size - 16) * 8);
         ^
286. 
287.     if(!get_bits1(&gb)) {

libavcodec/get_bits.h:352:1: start of procedure init_get_bits()
  350.  * @param bit_size the size of the buffer in bits
  351.  */
  352. static inline void init_get_bits(GetBitContext *s, const uint8_t *buffer,
       ^
  353.                                  int bit_size)
  354. {

libavcodec/get_bits.h:355:5: 
  353.                                  int bit_size)
  354. {
  355.     int buffer_size = (bit_size+7)>>3;
           ^
  356.     if (buffer_size < 0 || bit_size < 0) {
  357.         buffer_size = bit_size = 0;

libavcodec/get_bits.h:356:9: Taking true branch
  354. {
  355.     int buffer_size = (bit_size+7)>>3;
  356.     if (buffer_size < 0 || bit_size < 0) {
               ^
  357.         buffer_size = bit_size = 0;
  358.         buffer = NULL;

libavcodec/get_bits.h:357:9: 
  355.     int buffer_size = (bit_size+7)>>3;
  356.     if (buffer_size < 0 || bit_size < 0) {
  357.         buffer_size = bit_size = 0;
               ^
  358.         buffer = NULL;
  359.     }

libavcodec/get_bits.h:358:9: 
  356.     if (buffer_size < 0 || bit_size < 0) {
  357.         buffer_size = bit_size = 0;
  358.         buffer = NULL;
               ^
  359.     }
  360. 

libavcodec/get_bits.h:361:5: 
  359.     }
  360. 
  361.     s->buffer       = buffer;
           ^
  362.     s->size_in_bits = bit_size;
  363. #if !UNCHECKED_BITSTREAM_READER

libavcodec/get_bits.h:362:5: 
  360. 
  361.     s->buffer       = buffer;
  362.     s->size_in_bits = bit_size;
           ^
  363. #if !UNCHECKED_BITSTREAM_READER
  364.     s->size_in_bits_plus8 = bit_size + 8;

libavcodec/get_bits.h:364:5: 
  362.     s->size_in_bits = bit_size;
  363. #if !UNCHECKED_BITSTREAM_READER
  364.     s->size_in_bits_plus8 = bit_size + 8;
           ^
  365. #endif
  366.     s->buffer_end   = buffer + buffer_size;

libavcodec/get_bits.h:366:5: 
  364.     s->size_in_bits_plus8 = bit_size + 8;
  365. #endif
  366.     s->buffer_end   = buffer + buffer_size;
           ^
  367.     s->index        = 0;
  368. }

libavcodec/get_bits.h:367:5: 
  365. #endif
  366.     s->buffer_end   = buffer + buffer_size;
  367.     s->index        = 0;
           ^
  368. }
  369. 

libavcodec/get_bits.h:368:1: return from a call to init_get_bits
  366.     s->buffer_end   = buffer + buffer_size;
  367.     s->index        = 0;
  368. }
       ^
  369. 
  370. static inline void align_get_bits(GetBitContext *s)

libavcodec/smacker.c:287:9: 
285.     init_get_bits(&gb, smk->avctx->extradata + 16, (smk->avctx->extradata_size - 16) * 8);
286. 
287.     if(!get_bits1(&gb)) {
             ^
288.         av_log(smk->avctx, AV_LOG_INFO, "Skipping MMAP tree\n");
289.         smk->mmap_tbl = av_malloc(sizeof(int) * 2);

libavcodec/get_bits.h:268:1: start of procedure get_bits1()
  266. }
  267. 
  268. static inline unsigned int get_bits1(GetBitContext *s)
       ^
  269. {
  270.     unsigned int index = s->index;

libavcodec/get_bits.h:270:5: 
  268. static inline unsigned int get_bits1(GetBitContext *s)
  269. {
  270.     unsigned int index = s->index;
           ^
  271.     uint8_t result = s->buffer[index>>3];
  272. #ifdef BITSTREAM_READER_LE

libavcodec/get_bits.h:271:5: 
  269. {
  270.     unsigned int index = s->index;
  271.     uint8_t result = s->buffer[index>>3];
           ^
  272. #ifdef BITSTREAM_READER_LE
  273.     result >>= index & 7;
