Crash reading iff_ilbm

[Carl Eugen Hoyos]

(gdb) r -vcodec iff_ilbm -i blox.avi
Starting program: ffmpeg_g -vcodec iff_ilbm -i blox.avi
[Thread debugging using libthread_db enabled]
[New Thread 0xb797d6c0 (LWP 20781)]
ffmpeg version N-41080-g394b692 Copyright (c) 2000-2012 the FFmpeg developers
  built on May 28 2012 14:04:27 with gcc 4.3.2
  configuration: --cc=/usr/local/gcc-4.3.2/bin/gcc --enable-gpl --enable-libopenjpeg --enable-libvorbis --enable-libspeex --enable-libmp3lame --enable-libtheora --extra-ldflags=-lm --enable-libvpx --enable-libxavs
  libavutil      51. 55.100 / 51. 55.100
  libavcodec     54. 23.100 / 54. 23.100
  libavformat    54.  6.101 / 54.  6.101
  libavdevice    54.  0.100 / 54.  0.100
  libavfilter     2. 77.100 /  2. 77.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb797d6c0 (LWP 20781)]
extract_header (avctx=0x901e700, avpkt=0x0) at libavcodec/iff.c:194
194         int palette_size = avctx->extradata_size - AV_RB16(avctx->extradata);
(gdb) bt
#0  extract_header (avctx=0x901e700, avpkt=0x0) at libavcodec/iff.c:194
#1  0x08413dde in decode_init (avctx=0x901e700) at libavcodec/iff.c:335
#2  0x08590345 in avcodec_open2 (avctx=0x901e700, codec=Cannot access memory at address 0x4
)
    at libavcodec/utils.c:925
#3  0x0819e8ac in avformat_find_stream_info (ic=0x9018440, options=0x90183c0)
    at libavformat/utils.c:2485
#4  0x0805682b in opt_input_file (o=0xbfbaa228, opt=0xbfbab280 "i",
    filename=0xbfbab282 "blox.avi") at ffmpeg.c:4327
#5  0x08062d72 in parse_option (optctx=0xbfbaa228, opt=0xbfbab280 "i",
    arg=0xbfbab282 "blox.avi", options=0x88e7540) at cmdutils.c:305
#6  0x08063103 in parse_options (optctx=0xbfbaa228, argc=5, argv=0xbfbaa454,
    options=0x88e7540, parse_arg_function=0x805d420 <opt_output_file>)
    at cmdutils.c:338
#7  0x0805c4f6 in main (argc=5, argv=0xbfbaa454) at ffmpeg.c:5906
(gdb) disass $pc-32 $pc+32
Dump of assembler code from 0x8411cae to 0x8411cee:
0x08411cae:     add    %al,(%eax)
0x08411cb0 <extract_header+0>:  sub    $0x4c,%esp
0x08411cb3 <extract_header+3>:  mov    %esi,0x40(%esp)
0x08411cb7 <extract_header+7>:  mov    %eax,%esi
0x08411cb9 <extract_header+9>:  mov    %ebp,0x48(%esp)
0x08411cbd <extract_header+13>: mov    %ebx,0x3c(%esp)
0x08411cc1 <extract_header+17>: mov    %edi,0x44(%esp)
0x08411cc5 <extract_header+21>: mov    0x64(%eax),%ebx
0x08411cc8 <extract_header+24>: mov    0x68(%eax),%ecx
0x08411ccb <extract_header+27>: mov    0x40(%eax),%edi
0x08411cce <extract_header+30>: movzwl (%ebx),%eax
0x08411cd1 <extract_header+33>: mov    %ecx,%ebp
0x08411cd3 <extract_header+35>: rol    $0x8,%ax
0x08411cd7 <extract_header+39>: movzwl %ax,%eax
0x08411cda <extract_header+42>: sub    %eax,%ebp
0x08411cdc <extract_header+44>: test   %edx,%edx
0x08411cde <extract_header+46>: mov    %ebp,0x2c(%esp)
0x08411ce2 <extract_header+50>: je     0x8411e10 <extract_header+352>
0x08411ce8 <extract_header+56>: mov    0x14(%edx),%ecx
0x08411ceb <extract_header+59>: cmp    $0x1,%ecx
End of assembler dump.
(gdb) info register
eax            0x901e700        151119616
ecx            0x0      0
edx            0x0      0
ebx            0x0      0
esp            0xbfba9c40       0xbfba9c40
ebp            0x90183c0        0x90183c0
esi            0x901e700        151119616
edi            0x901f100        151122176
eip            0x8411cce        0x8411cce <extract_header+30>
eflags         0x10282  [ SF IF RF ]
cs             0x73     115
ss             0x7b     123
ds             0x7b     123
es             0x7b     123
fs             0x0      0
gs             0x33     51