A NULL pointer dereference exists in the function swf_DeleteFilter in swffilter.c

[cxlzff]

system info

Ubuntu x86_64, clang 6.0, swfdump (latest master a9d5082)

Command line

./src/swfdump -D @@

AddressSanitizer output

==5769==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x00000042ba78 bp 0x000000000073 sp 0x7fffffffdea0 T0)
#0 0x42ba77 in swf_DeleteFilter modules/swffilter.c:290
#1 0x40de0b in dumpButton2Actions /test/swftools-asan/src/swfdump.c:245
#2 0x409448 in main /test/swftools-asan/src/swfdump.c:1600
#3 0x7ffff68a683f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)
#4 0x40c168 in _start (/test/swftools-asan/src/swfdump+0x40c168)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV modules/swffilter.c:290 swf_DeleteFilter
==5769==ABORTING

POC
swf_DeleteFilter_poc