libavcodec/iirfilter.c:66: error: Null Dereference
  pointer `c` last assigned on line 65 could be null and is dereferenced at line 66, column 5.

libavcodec/iirfilter.c:50:9: start of procedure ff_iir_filter_init_coeffs()
48. #define MAXORDER 30
49. 
50. av_cold struct FFIIRFilterCoeffs* ff_iir_filter_init_coeffs(enum IIRFilterType filt_type,
            ^
51.                                                     enum IIRFilterMode filt_mode,
52.                                                     int order, float cutoff_ratio,

libavcodec/iirfilter.c:60:8: Taking false branch
58.     double p[MAXORDER + 1][2];
59. 
60.     if(filt_type != FF_FILTER_TYPE_BUTTERWORTH || filt_mode != FF_FILTER_MODE_LOWPASS)
           ^
61.         return NULL;
62.     if(order <= 1 || (order & 1) || order > MAXORDER || cutoff_ratio >= 1.0)

libavcodec/iirfilter.c:60:51: Taking false branch
58.     double p[MAXORDER + 1][2];
59. 
60.     if(filt_type != FF_FILTER_TYPE_BUTTERWORTH || filt_mode != FF_FILTER_MODE_LOWPASS)
                                                      ^
61.         return NULL;
62.     if(order <= 1 || (order & 1) || order > MAXORDER || cutoff_ratio >= 1.0)

libavcodec/iirfilter.c:62:8: Taking false branch
60.     if(filt_type != FF_FILTER_TYPE_BUTTERWORTH || filt_mode != FF_FILTER_MODE_LOWPASS)
61.         return NULL;
62.     if(order <= 1 || (order & 1) || order > MAXORDER || cutoff_ratio >= 1.0)
           ^
63.         return NULL;
64. 

libavcodec/iirfilter.c:62:23: Taking false branch
60.     if(filt_type != FF_FILTER_TYPE_BUTTERWORTH || filt_mode != FF_FILTER_MODE_LOWPASS)
61.         return NULL;
62.     if(order <= 1 || (order & 1) || order > MAXORDER || cutoff_ratio >= 1.0)
                          ^
63.         return NULL;
64. 

libavcodec/iirfilter.c:62:37: Taking false branch
60.     if(filt_type != FF_FILTER_TYPE_BUTTERWORTH || filt_mode != FF_FILTER_MODE_LOWPASS)
61.         return NULL;
62.     if(order <= 1 || (order & 1) || order > MAXORDER || cutoff_ratio >= 1.0)
                                        ^
63.         return NULL;
64. 

libavcodec/iirfilter.c:62:57: Taking false branch
60.     if(filt_type != FF_FILTER_TYPE_BUTTERWORTH || filt_mode != FF_FILTER_MODE_LOWPASS)
61.         return NULL;
62.     if(order <= 1 || (order & 1) || order > MAXORDER || cutoff_ratio >= 1.0)
                                                            ^
63.         return NULL;
64. 

libavcodec/iirfilter.c:65:5: 
63.         return NULL;
64. 
65.     c = av_malloc(sizeof(FFIIRFilterCoeffs));
        ^
66.     c->cx = av_malloc(sizeof(c->cx[0]) * ((order >> 1) + 1));
67.     c->cy = av_malloc(sizeof(c->cy[0]) * order);

libavutil/mem.c:64:1: start of procedure av_malloc()
  62.    linker will do it automatically. */
  63. 
  64. void *av_malloc(FF_INTERNAL_MEM_TYPE size)
      ^
  65. {
  66.     void *ptr = NULL;

libavutil/mem.c:66:5: 
  64. void *av_malloc(FF_INTERNAL_MEM_TYPE size)
  65. {
  66.     void *ptr = NULL;
          ^
  67. #if CONFIG_MEMALIGN_HACK
  68.     long diff;

libavutil/mem.c:72:8: Taking false branch
  70. 
  71.     /* let's disallow possible ambiguous cases */
  72.     if(size > (INT_MAX-16) )
             ^
  73.         return NULL;
  74. 

libavutil/mem.c:83:9: Taking true branch
  81.     ((char*)ptr)[-1]= diff;
  82. #elif HAVE_POSIX_MEMALIGN
  83.     if (posix_memalign(&ptr,16,size))
              ^
  84.         ptr = NULL;
  85. #elif HAVE_MEMALIGN

libavutil/mem.c:84:9: 
  82. #elif HAVE_POSIX_MEMALIGN
  83.     if (posix_memalign(&ptr,16,size))
  84.         ptr = NULL;
              ^
  85. #elif HAVE_MEMALIGN
  86.     ptr = memalign(16,size);

libavutil/mem.c:116:5: 
  114.     ptr = malloc(size);
  115. #endif
  116.     return ptr;
           ^
  117. }
  118. 

libavutil/mem.c:117:1: return from a call to av_malloc
  115. #endif
  116.     return ptr;
  117. }
       ^
  118. 
  119. void *av_realloc(void *ptr, FF_INTERNAL_MEM_TYPE size)

libavcodec/iirfilter.c:66:5: 
64. 
65.     c = av_malloc(sizeof(FFIIRFilterCoeffs));
66.     c->cx = av_malloc(sizeof(c->cx[0]) * ((order >> 1) + 1));
        ^
67.     c->cy = av_malloc(sizeof(c->cy[0]) * order);
68.     c->order = order;

libavutil/mem.c:64:1: start of procedure av_malloc()
  62.    linker will do it automatically. */
  63. 
  64. void *av_malloc(FF_INTERNAL_MEM_TYPE size)
      ^
  65. {
  66.     void *ptr = NULL;

libavutil/mem.c:66:5: 
  64. void *av_malloc(FF_INTERNAL_MEM_TYPE size)
  65. {
  66.     void *ptr = NULL;
          ^
  67. #if CONFIG_MEMALIGN_HACK
  68.     long diff;

libavutil/mem.c:72:8: Taking true branch
  70. 
  71.     /* let's disallow possible ambiguous cases */
  72.     if(size > (INT_MAX-16) )
             ^
  73.         return NULL;
  74. 

libavutil/mem.c:73:9: 
  71.     /* let's disallow possible ambiguous cases */
  72.     if(size > (INT_MAX-16) )
  73.         return NULL;
              ^
  74. 
  75. #if CONFIG_MEMALIGN_HACK

libavutil/mem.c:117:1: return from a call to av_malloc
  115. #endif
  116.     return ptr;
  117. }
       ^
  118. 
  119. void *av_realloc(void *ptr, FF_INTERNAL_MEM_TYPE size)
