Reproducer cmdline:
giftrans -l a4ac94f0_reproducer

Command output:
Global Color Table:
Color 0: Red 253, Green 253, Blue 4, #fdfd04
Color 1: Red 253, Green 253, Blue 252, #fdfdfc
Color 2: Red 5, Green 5, Blue 5, #050505 (gray2, grey2)
Color 3: Red 244, Green 244, Blue 0, #f4f400
Color 4: Red 236, Green 236, Blue 0, #ecec00
Color 5: Red 204, Green 204, Blue 0, #cccc00
Color 6: Red 226, Green 226, Blue 0, #e2e200
Color 7: Red 212, Green 212, Blue 0, #d4d400
Color 8: Red 197, Green 197, Blue 0, #c5c500
Color 9: Red 116, Green 116, Blue 0, #747400
Color 10: Red 180, Green 180, Blue 0, #b4b400
Color 11: Red 186, Green 186, Blue 0, #baba00
Color 12: Red 164, Green 164, Blue 0, #a4a400
Color 13: Red 221, Green 221, Blue 0, #dddd00
Color 14: Red 156, Green 156, Blue 0, #9c9c00
Color 15: Red 108, Green 108, Blue 0, #6c6c00
Color 16: Red 208, Green 208, Blue 32, #d0d020
Color 17: Red 93, Green 93, Blue 0, #5d5d00
Color 18: Red 148, Green 148, Blue 0, #949400
Color 19: Red 66, Green 66, Blue 0, #424200
Color 20: Red 125, Green 125, Blue 0, #7d7d00
Color 21: Red 76, Green 76, Blue 0, #4c4c00
Color 22: Red 59, Green 59, Blue 0, #3b3b00
Color 23: Red 140, Green 140, Blue 0, #8c8c00
Color 24: Red 132, Green 132, Blue 0, #848400
Color 25: Red 50, Green 50, Blue 0, #323200
Color 26: Red 84, Green 84, Blue 0, #545400
Color 27: Red 235, Green 235, Blue 3, #ebeb03
Color 28: Red 236, Green 236, Blue 228, #ecece4
Color 29: Red 245, Green 245, Blue 0, #f5f500
Color 30: Red 101, Green 101, Blue 0, #656500
Color 31: Red 172, Green 172, Blue 0, #acac00
Color 32: Red 140, Green 140, Blue 67, #8c8c43
Color 33: Red 250, Green 250, Blue 247, #fafaf7
Color 34: Red 170, Green 170, Blue 141, #aaaa8d
Color 35: Red 221, Green 221, Blue 205, #ddddcd
Color 36: Red 196, Green 196, Blue 95, #c4c45f
Color 37: Red 228, Green 228, Blue 192, #e4e4c0
Color 38: Red 238, Green 238, Blue 234, #eeeeea
Color 39: Red 229, Green 229, Blue 0, #e5e500
Color 40: Red 203, Green 203, Blue 128, #cbcb80
Color 41: Red 227, Green 227, Blue 223, #e3e3df
Color 42: Red 221, Green 221, Blue 173, #ddddad
Color 43: Red 147, Green 147, Blue 89, #939359
Color 44: Red 44, Green 44, Blue 5, #2c2c05
Color 45: Red 196, Green 196, Blue 98, #c4c462
Color 46: Red 197, Green 197, Blue 173, #c5c5ad
Color 47: Red 152, Green 152, Blue 23, #989817
Color 48: Red 179, Green 179, Blue 43, #b3b32b
Color 49: Red 116, Green 116, Blue 27, #74741b
Color 50: Red 234, Green 234, Blue 214, #eaead6
Color 51: Red 127, Green 127, Blue 108, #7f7f6c
Color 52: Red 139, Green 139, Blue 103, #8b8b67
Color 53: Red 228, Green 228, Blue 209, #e4e4d1
Color 54: Red 184, Green 184, Blue 41, #b8b829
Color 55: Red 123, Green 123, Blue 61, #7b7b3d
Color 56: Red 185, Green 185, Blue 53, #b9b935
Color 57: Red 119, Green 119, Blue 57, #777739
Color 58: Red 218, Green 218, Blue 213, #dadad5
Color 59: Red 67, Green 67, Blue 35, #434323
Color 60: Red 182, Green 182, Blue 85, #b6b655
Color 61: Red 158, Green 158, Blue 73, #9e9e49
Color 62: Red 104, Green 104, Blue 78, #68684e
Color 63: Red 197, Green 197, Blue 156, #c5c59c
Color 64: Red 119, Green 119, Blue 10, #77770a
Color 65: Red 193, Green 193, Blue 132, #c1c184
Color 66: Red 93, Green 93, Blue 14, #5d5d0e
Color 67: Red 243, Green 243, Blue 237, #f3f3ed
Color 68: Red 247, Green 247, Blue 246, #f7f7f6
Color 69: Red 203, Green 203, Blue 184, #cbcbb8
Color 70: Red 244, Green 244, Blue 230, #f4f4e6
Color 71: Red 97, Green 97, Blue 17, #616111
Color 72: Red 209, Green 209, Blue 115, #d1d173
Color 73: Red 207, Green 207, Blue 116, #cfcf74
Color 74: Red 181, Green 181, Blue 28, #b5b51c
Color 75: Red 163, Green 163, Blue 28, #a3a31c
Color 76: Red 168, Green 168, Blue 123, #a8a87b
Color 77: Red 133, Green 133, Blue 18, #858512
Color 78: Red 170, Green 170, Blue 18, #aaaa12
Color 79: Red 135, Green 135, Blue 24, #878718
Color 80: Red 16, Green 16, Blue 0, #101000
Color 81: Red 36, Green 36, Blue 0, #242400
Color 82: Red 20, Green 20, Blue 17, #141411
Color 83: Red 46, Green 46, Blue 28, #2e2e1c
Color 84: Red 150, Green 150, Blue 28, #96961c
Color 85: Red 245, Green 245, Blue 14, #f5f50e
Color 86: Red 182, Green 182, Blue 33, #b6b621
Color 87: Red 54, Green 54, Blue 0, #363600
Color 88: Red 154, Green 154, Blue 130, #9a9a82
Color 89: Red 162, Green 162, Blue 150, #a2a296
Color 90: Red 49, Green 49, Blue 11, #31310b
Color 91: Red 181, Green 181, Blue 23, #b5b517
Color 92: Red 211, Green 211, Blue 149, #d3d395
Color 93: Red 209, Green 209, Blue 135, #d1d187
Color 94: Red 100, Green 100, Blue 0, #646400
Color 95: Red 175, Green 175, Blue 167, #afafa7
Color 96: Red 215, Green 215, Blue 177, #d7d7b1
Color 97: Red 216, Green 216, Blue 177, #d8d8b1
Color 98: Red 176, Green 176, Blue 165, #b0b0a5
Color 99: Red 214, Green 214, Blue 156, #d6d69c
Color 100: Red 10, Green 10, Blue 10, #0a0a0a (gray4, grey4)
Color 101: Red 218, Green 218, Blue 164, #dadaa4
Color 102: Red 186, Green 186, Blue 161, #babaa1
Color 103: Red 236, Green 236, Blue 220, #ececdc
Color 104: Red 196, Green 196, Blue 104, #c4c468
Color 105: Red 90, Green 90, Blue 40, #5a5a28
Color 106: Red 137, Green 137, Blue 77, #89894d
Color 107: Red 90, Green 90, Blue 39, #5a5a27
Color 108: Red 211, Green 211, Blue 205, #d3d3cd
Color 109: Red 133, Green 133, Blue 53, #858535
Color 110: Red 164, Green 164, Blue 123, #a4a47b
Color 111: Red 150, Green 150, Blue 124, #96967c
Color 112: Red 137, Green 137, Blue 59, #89893b
Color 113: Red 204, Green 204, Blue 198, #ccccc6
Color 114: Red 163, Green 163, Blue 118, #a3a376
Color 115: Red 78, Green 78, Blue 40, #4e4e28
Color 116: Red 30, Green 30, Blue 30, #1e1e1e
Color 117: Red 120, Green 120, Blue 28, #78781c
Color 118: Red 25, Green 25, Blue 15, #19190f
Color 119: Red 134, Green 134, Blue 37, #868625
Color 120: Red 105, Green 105, Blue 31, #69691f
Color 121: Red 92, Green 92, Blue 31, #5c5c1f
Color 122: Red 193, Green 193, Blue 26, #c1c11a
Color 123: Red 185, Green 185, Blue 31, #b9b91f
Color 124: Red 226, Green 226, Blue 26, #e2e21a
Color 125: Red 234, Green 234, Blue 20, #eaea14
Color 126: Red 56, Green 56, Blue 33, #383821
Color 127: Red 198, Green 198, Blue 32, #c6c620
Color 128: Red 156, Green 156, Blue 32, #9c9c20
Color 129: Red 17, Green 17, Blue 13, #11110d
Color 130: Red 37, Green 37, Blue 0, #252500
Color 131: Red 25, Green 25, Blue 0, #191900
Color 132: Red 210, Green 210, Blue 24, #d2d218
Color 133: Red 33, Green 33, Blue 33, #212121 (gray13, grey13)
Color 134: Red 217, Green 217, Blue 23, #d9d917
Color 135: Red 63, Green 63, Blue 27, #3f3f1b
Color 136: Red 222, Green 222, Blue 26, #dede1a
Color 137: Red 51, Green 51, Blue 35, #333323
Color 138: Red 249, Green 249, Blue 15, #f9f90f
Color 139: Red 170, Green 170, Blue 49, #aaaa31
Color 140: Red 109, Green 109, Blue 46, #6d6d2e
Color 141: Red 130, Green 130, Blue 10, #82820a
Color 142: Red 211, Green 211, Blue 10, #d3d30a
Color 143: Red 186, Green 186, Blue 12, #baba0c
Color 144: Red 35, Green 35, Blue 23, #232317
Color 145: Red 146, Green 146, Blue 41, #929229
Color 146: Red 112, Green 112, Blue 41, #707029
Color 147: Red 164, Green 164, Blue 43, #a4a42b
Color 148: Red 152, Green 152, Blue 42, #98982a
Color 149: Red 251, Green 251, Blue 22, #fbfb16
Color 150: Red 82, Green 82, Blue 30, #52521e
Color 151: Red 76, Green 76, Blue 29, #4c4c1d
Color 152: Red 200, Green 200, Blue 31, #c8c81f
Color 153: Red 64, Green 64, Blue 31, #40401f
Color 154: Red 9, Green 9, Blue 2, #090902
Color 155: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 156: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 157: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 158: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 159: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 160: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 161: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 162: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 163: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 164: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 165: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 166: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 167: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 168: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 169: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 170: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 171: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 172: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 173: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 174: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 175: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 176: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 177: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 178: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 179: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 180: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 181: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 182: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 183: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 184: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 185: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 186: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 187: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 188: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 189: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 190: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 191: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 192: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 193: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 194: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 195: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 196: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 197: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 198: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 199: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 200: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 201: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 202: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 203: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 204: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 205: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 206: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 207: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 208: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 209: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 210: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 211: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 212: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 213: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 214: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 215: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 216: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 217: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 218: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 219: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 220: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 221: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 222: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 223: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 224: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 225: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 226: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 227: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 228: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 229: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 230: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 231: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 232: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 233: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 234: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 235: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 236: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 237: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 238: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 239: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 240: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 241: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 242: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 243: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 244: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 245: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 246: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 247: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 248: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 249: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 250: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 251: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 252: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 253: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 254: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
Color 255: Red 0, Green 0, Blue 0, #000000 (black, gray0, grey0)
*** buffer overflow detected ***: ../../giftrans terminated
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7338f)[0x7ffff7a8838f]
/lib/x86_64-linux-gnu/libc.so.6(__fortify_fail+0x5c)[0x7ffff7b1fc9c]
/lib/x86_64-linux-gnu/libc.so.6(+0x109b60)[0x7ffff7b1eb60]
/lib/x86_64-linux-gnu/libc.so.6(__fread_chk+0x13c)[0x7ffff7b1f23c]
../../giftrans[0x40b492]
../../giftrans[0x402cc9]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5)[0x7ffff7a36ec5]
../../giftrans[0x40324e]
======= Memory map: ========
00400000-00413000 r-xp 00000000 fc:01 6403298
  /home/jodicun/opt/giftrans-1.12.2/giftrans
00612000-00613000 r--p 00012000 fc:01 6403298
  /home/jodicun/opt/giftrans-1.12.2/giftrans
00613000-00614000 rw-p 00013000 fc:01 6403298
  /home/jodicun/opt/giftrans-1.12.2/giftrans
00614000-00635000 rw-p 00000000 00:00 0                                  [heap]
7ffff77ff000-7ffff7815000 r-xp 00000000 fc:01 4980886
  /lib/x86_64-linux-gnu/libgcc_s.so.1
7ffff7815000-7ffff7a14000 ---p 00016000 fc:01 4980886
  /lib/x86_64-linux-gnu/libgcc_s.so.1
7ffff7a14000-7ffff7a15000 rw-p 00015000 fc:01 4980886
  /lib/x86_64-linux-gnu/libgcc_s.so.1
7ffff7a15000-7ffff7bd0000 r-xp 00000000 fc:01 4989799
  /lib/x86_64-linux-gnu/libc-2.19.so
7ffff7bd0000-7ffff7dcf000 ---p 001bb000 fc:01 4989799
  /lib/x86_64-linux-gnu/libc-2.19.so
7ffff7dcf000-7ffff7dd3000 r--p 001ba000 fc:01 4989799
  /lib/x86_64-linux-gnu/libc-2.19.so
7ffff7dd3000-7ffff7dd5000 rw-p 001be000 fc:01 4989799
  /lib/x86_64-linux-gnu/libc-2.19.so
7ffff7dd5000-7ffff7dda000 rw-p 00000000 00:00 0
7ffff7dda000-7ffff7dfd000 r-xp 00000000 fc:01 4989796
  /lib/x86_64-linux-gnu/ld-2.19.so
7ffff7fe1000-7ffff7fe4000 rw-p 00000000 00:00 0
7ffff7ff6000-7ffff7ffa000 rw-p 00000000 00:00 0
7ffff7ffa000-7ffff7ffc000 r-xp 00000000 00:00 0                          [vdso]
7ffff7ffc000-7ffff7ffd000 r--p 00022000 fc:01 4989796
  /lib/x86_64-linux-gnu/ld-2.19.so
7ffff7ffd000-7ffff7ffe000 rw-p 00023000 fc:01 4989796
  /lib/x86_64-linux-gnu/ld-2.19.so
7ffff7ffe000-7ffff7fff000 rw-p 00000000 00:00 0
7ffffffde000-7ffffffff000 rw-p 00000000 00:00 0                          [stack]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0
  [vsyscall]
Aborted (core dumped)


I was fuzzing giftrans with American Fuzzy Lop and found this bug. I
have no expected behavior from the software.  The reproducer file and
a GDB log file with backtrace are attached.

Regards,
-Jodie Cunningham