New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

A Segmentation fault #4

CCCCCrash opened this Issue Nov 18, 2018 · 1 comment


None yet
2 participants

CCCCCrash commented Nov 18, 2018

just as pic show

the pic

when the libansilove parser crafted file, it will cause a OOB if the seqTok assignned wrong

as the valgrind detect, there is a "Invalid read"

root@Starry:~/fuzz/ansilove# valgrind ./ansilove -i poc.ans
==30030== Memcheck, a memory error detector
==30030== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==30030== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==30030== Command: ./ansilove -i poc.ans
AnsiLove/C 3.0.9 - ANSI / ASCII art to PNG converter
Copyright (c) 2011-2018 Stefan Vogt, Brian Cassidy, and Frederic Cambus.
==30030== Invalid read of size 1
==30030== at 0x50F9570: __strcmp_sse2_unaligned (strcmp-sse2-unaligned.S:24)
==30030== by 0x4023C0: main (main.c:238)
==30030== Address 0x81a82b0 is 0 bytes inside a block of size 144 free'd
==30030== at 0x4C2EDEB: free (in /usr/lib/valgrind/
==30030== by 0x4051E6: sauceReadFile (sauce.c:34)
==30030== by 0x4051E6: sauceReadFileName (sauce.c:22)
==30030== by 0x40236F: main (main.c:230)
==30030== Block was alloc'd at
==30030== at 0x4C2DB8F: malloc (in /usr/lib/valgrind/
==30030== by 0x405198: sauceReadFile (sauce.c:31)
==30030== by 0x405198: sauceReadFileName (sauce.c:22)
==30030== by 0x40236F: main (main.c:230)

Input File: poc.ans
Output File: poc.ans.png
==30030== Conditional jump or move depends on uninitialised value(s)
==30030== at 0x4E3D5B4: ansilove_ansi (in /usr/local/lib/
==30030== by 0x4038A2: main (main.c:304)
==30030== Invalid read of size 1
==30030== at 0x5095454: ____strtol_l_internal (strtol_l.c:293)
==30030== by 0x405D0F: strtonum (strtonum.c:50)
==30030== by 0x4E3D481: ansilove_ansi (in /usr/local/lib/
==30030== by 0x4038A2: main (main.c:304)
==30030== Address 0x0 is not stack'd, malloc'd or (recently) free'd
==30030== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==30030== Access not within mapped region at address 0x0
==30030== at 0x5095454: ____strtol_l_internal (strtol_l.c:293)
==30030== by 0x405D0F: strtonum (strtonum.c:50)
==30030== by 0x4E3D481: ansilove_ansi (in /usr/local/lib/
==30030== by 0x4038A2: main (main.c:304)
==30030== If you believe this happened as a result of a stack
==30030== overflow in your program's main thread (unlikely but
==30030== possible), you can try to increase the size of the
==30030== main thread stack using the --main-stacksize= flag.
==30030== The main thread stack size used in this run was 8388608.
==30030== HEAP SUMMARY:
==30030== in use at exit: 3,361 bytes in 4 blocks
==30030== total heap usage: 232 allocs, 228 frees, 285,685 bytes allocated
==30030== LEAK SUMMARY:
==30030== definitely lost: 0 bytes in 0 blocks
==30030== indirectly lost: 0 bytes in 0 blocks
==30030== possibly lost: 0 bytes in 0 blocks
==30030== still reachable: 3,361 bytes in 4 blocks
==30030== suppressed: 0 bytes in 0 blocks
==30030== Rerun with --leak-check=full to see details of leaked memory
==30030== For counts of detected and suppressed errors, rerun with: -v
==30030== Use --track-origins=yes to see where uninitialised values come from
==30030== ERROR SUMMARY: 169 errors from 3 contexts (suppressed: 0 from 0)
Segmentation fault


@fcambus fcambus closed this in 1142259 Nov 22, 2018


This comment has been minimized.


fcambus commented Nov 22, 2018

I just pushed a fix for this, thanks for reporting the issue!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment