SDL_LoadAnimatedGif SEGV

[GHTHYS]

I use llvm-10 and AddressSanitizer to build SDLaffgif. The poc file is :

./SDLaffgif CA_file2_0

The ASAN information :

==15828==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x0000004c6166 bp 0x7ffff2a64c70 sp 0x7ffff2a64bb0 T0)
==15828==The signal is caused by a READ memory access.
==15828==Hint: address points to the zero page.
    #0 0x4c6166 in SDL_LoadAnimatedGif /home/zhangzheng/Desktop/cve-libf/cve-libf/ngiflib/ngiflibSDL.c:177:63
    #1 0x4c4bdc in main /home/zhangzheng/Desktop/cve-libf/cve-libf/ngiflib/SDLaffgif.c:107:14
    #2 0x7f9bc569d0b2 in __libc_start_main /build/glibc-sMfBJT/glibc-2.31/csu/../csu/libc-start.c:308:16
    #3 0x41c46d in _start (/home/zhangzheng/Desktop/cve-libf/cve-libf/ngiflib/SDLaffgif+0x41c46d)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/zhangzheng/Desktop/cve-libf/cve-libf/ngiflib/ngiflibSDL.c:177:63 in SDL_LoadAnimatedGif
==15828==ABORTING