SEGV exits in the function free_lines in swftools/lib/modules/swfshape.c:1094:16

[guangbuming]

project

https://github.com/matthiaskramm/swftools
version:0.9.2

os info

Ubuntu20.04 TLS

poc

2_poc.zip

build

git clone https://github.com/matthiaskramm/swftools.git
cd swftools
./configure --disable-shared && make
./src/swfc 2_poc

ASAN Info

drawer: Warning: unknown primitive 'mov'
AddressSanitizer:DEADLYSIGNAL
=================================================================
==2662951==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000020 (pc 0x000000542e03 bp 0x7fffffffdf20 sp 0x7fffffffdd70 T0)
==2662951==The signal is caused by a READ memory access.
==2662951==Hint: address points to the zero page.
    #0 0x542e03 in free_lines /home/swftools/lib/modules/swfshape.c:1094:16
    #1 0x542bd8 in swf_RecodeShapeData /home/swftools/lib/modules/swfshape.c:1122:5
    #2 0x4db13e in s_filled /home/swftools/src/swfc.c:1285:5
    #3 0x4f9af7 in c_primitive /home/swftools/src/swfc.c:3855:22
    #4 0x4ee709 in parseArgumentsForCommand /home/swftools/src/swfc.c:4475:5
    #5 0x4ee709 in main /home/swftools/src/swfc.c:4598:2
    #6 0x7ffff7c29082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16
    #7 0x41d63d in _start (/home/swftools/src/swfc+0x41d63d)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/swftools/lib/modules/swfshape.c:1094:16 in free_lines
==2662951==ABORTING