libavcodec/smacker.c:286: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 284 could be null and is dereferenced by call to `get_bits1()` at line 286, column 9.

libavcodec/smacker.c:275:1: start of procedure decode_header_trees()
273. }
274. 
275. static int decode_header_trees(SmackVContext *smk) {
     ^
276.     GetBitContext gb;
277.     int mmap_size, mclr_size, full_size, type_size;

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

libavcodec/smacker.c:280:5: 
278. 
279.     mmap_size = AV_RL32(smk->avctx->extradata);
280.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
         ^
281.     full_size = AV_RL32(smk->avctx->extradata + 8);
282.     type_size = AV_RL32(smk->avctx->extradata + 12);

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

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

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

libavcodec/get_bits.h:391:1: start of procedure init_get_bits()
  389.  * responsible for checking for the buffer end yourself (take advantage of the padding)!
  390.  */
  391. static inline void init_get_bits(GetBitContext *s,
       ^
  392.                    const uint8_t *buffer, int bit_size)
  393. {

libavcodec/get_bits.h:394:5: 
  392.                    const uint8_t *buffer, int bit_size)
  393. {
  394.     int buffer_size = (bit_size+7)>>3;
           ^
  395.     if (buffer_size < 0 || bit_size < 0) {
  396.         buffer_size = bit_size = 0;

libavcodec/get_bits.h:395:9: Taking true branch
  393. {
  394.     int buffer_size = (bit_size+7)>>3;
  395.     if (buffer_size < 0 || bit_size < 0) {
               ^
  396.         buffer_size = bit_size = 0;
  397.         buffer = NULL;

libavcodec/get_bits.h:396:9: 
  394.     int buffer_size = (bit_size+7)>>3;
  395.     if (buffer_size < 0 || bit_size < 0) {
  396.         buffer_size = bit_size = 0;
               ^
  397.         buffer = NULL;
  398.     }

libavcodec/get_bits.h:397:9: 
  395.     if (buffer_size < 0 || bit_size < 0) {
  396.         buffer_size = bit_size = 0;
  397.         buffer = NULL;
               ^
  398.     }
  399. 

libavcodec/get_bits.h:400:5: 
  398.     }
  399. 
  400.     s->buffer       = buffer;
           ^
  401.     s->size_in_bits = bit_size;
  402.     s->buffer_end   = buffer + buffer_size;

libavcodec/get_bits.h:401:5: 
  399. 
  400.     s->buffer       = buffer;
  401.     s->size_in_bits = bit_size;
           ^
  402.     s->buffer_end   = buffer + buffer_size;
  403. #ifdef ALT_BITSTREAM_READER

libavcodec/get_bits.h:402:5: 
  400.     s->buffer       = buffer;
  401.     s->size_in_bits = bit_size;
  402.     s->buffer_end   = buffer + buffer_size;
           ^
  403. #ifdef ALT_BITSTREAM_READER
  404.     s->index        = 0;

libavcodec/get_bits.h:404:5: 
  402.     s->buffer_end   = buffer + buffer_size;
  403. #ifdef ALT_BITSTREAM_READER
  404.     s->index        = 0;
           ^
  405. #elif defined A32_BITSTREAM_READER
  406.     s->buffer_ptr   = (uint32_t*)((intptr_t)buffer & ~3);

libavcodec/get_bits.h:410:1: return from a call to init_get_bits
  408.     skip_bits_long(s, 0);
  409. #endif
  410. }
       ^
  411. 
  412. static inline void align_get_bits(GetBitContext *s)

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

libavcodec/get_bits.h:311:1: start of procedure get_bits1()
  309. }
  310. 
  311. static inline unsigned int get_bits1(GetBitContext *s){
       ^
  312. #ifdef ALT_BITSTREAM_READER
  313.     unsigned int index = s->index;

libavcodec/get_bits.h:313:5: 
  311. static inline unsigned int get_bits1(GetBitContext *s){
  312. #ifdef ALT_BITSTREAM_READER
  313.     unsigned int index = s->index;
           ^
  314.     uint8_t result = s->buffer[index>>3];
  315. #ifdef ALT_BITSTREAM_READER_LE

libavcodec/get_bits.h:314:5: 
  312. #ifdef ALT_BITSTREAM_READER
  313.     unsigned int index = s->index;
  314.     uint8_t result = s->buffer[index>>3];
           ^
  315. #ifdef ALT_BITSTREAM_READER_LE
  316.     result >>= index & 7;
