Skip Menu |
Report information
Id: 131644
Status: new
Priority: 0/
Queue: perl5

Owner: Nobody
Requestors: randir <sergey.aleynikov [at]>

Operating System: (no value)
PatchStatus: (no value)
Severity: medium
Type: core
Perl Version: 5.27.1
Fixed In: (no value)

Date: Sat, 24 Jun 2017 13:24:18 +0300
From: Sergey Aleynikov <sergey.aleynikov [...]>
To: perlbug [...]
Subject: Coredump in Perl_yyparse
Download (untitled) / with headers
text/plain 4.9k
This is a bug report for perl from, generated with the help of perlbug 1.40 running under perl 5.27.1. ----------------------------------------------------------------- [Please describe your issue here] While fuzzing perl v5.27.1-37-g4c95ee9f29 built with afl and run under libdislocator, I found the following program m|$0[s0{INIT{]]]|}m|$0[sub{T{]]]| to crash, even when run under -c for a syntax check. This is a regression between 5.16 and 5.18, bisect points to: commit 9ffcdca1f504cb09088413c074b35af4b7f247e3 Author: Father Chrysostomos <> Date: Mon Nov 12 23:04:16 2012 -0800 Don’t leak subs containing syntax errors I fixed this for BEGIN blocks earlier, but missed the fact that all subs are affected. When called without an o argument (from newANONATTRSUB), newATTRSUB is expected to return a CV with an unowned reference count of which the caller will take ownership. We cannot have newATTRSUB returning a freed CV, so we have it return null instead. But that means ck_anoncode and pm_runtime have to account for that. GDB info about the crash location is: (gdb) bt #0 0x00005585869a21b2 in Perl_yyparse (gramtype=258) at perly.c:497 #1 0x000055858691ed4c in S_parse_body (env=0x0, xsinit=0x5585868d7fe8 <xs_init>) at perl.c:2401 #2 0x000055858691d0b1 in perl_parse (my_perl=0x55858794e010, xsinit=0x5585868d7fe8 <xs_init>, argc=2, argv=0x7ffc8ef357f8, env=0x0) at perl.c:1719 #3 0x00005585868d7f26 in main (argc=2, argv=0x7ffc8ef357f8, env=0x7ffc8ef35810) at perlmain.c:121 (gdb) p PL_compcv $1 = (CV *) 0x0 [Please do not change anything below this line] ----------------------------------------------------------------- --- Flags: category=core severity=medium --- Site configuration information for perl 5.27.1: Configured by root at Sun May 28 01:44:41 MSK 2017. Summary of my perl5 (revision 5 version 26 subversion 0) configuration: Derived from: 4c95ee9f298c2edfc1382d540ff89288790e78b6 Platform: osname=linux osvers=4.9.0-3-amd64 archname=x86_64-linux uname='linux dorothy 4.9.0-3-amd64 #1 smp debian 4.9.25-1 (2017-05-02) x86_64 gnulinux ' config_args='-des -Dusedevel -DDEBUGGING -Dcc=afl-clang-fast -Doptimize=-O0 -g -ggdb3 -fno-omit-frame-pointer' hint=previous useposix=true d_sigaction=define useithreads=undef usemultiplicity=undef use64bitint=define use64bitall=define uselongdouble=undef usemymalloc=n default_inc_excludes_dot=define bincompat5005=undef Compiler: cc='afl-clang-fast' ccflags ='-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2' optimize='-O0 -g -ggdb3 -fno-omit-frame-pointer' cppflags='-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include' ccversion='' gccversion='4.2.1 Compatible Clang 3.9.1 (tags/RELEASE_391/rc2)' gccosandvers='' intsize=4 longsize=8 ptrsize=8 doublesize=8 byteorder=12345678 doublekind=3 d_longlong=define longlongsize=8 d_longdbl=define longdblsize=16 longdblkind=3 ivtype='long' ivsize=8 nvtype='double' nvsize=8 Off_t='off_t' lseeksize=8 alignbytes=8 prototype=define Linker and Libraries: ld='afl-clang-fast' ldflags =' -fstack-protector-strong -L/usr/local/lib' libpth=/usr/local/lib /usr/lib/llvm-3.9/bin/../lib/clang/3.9.1/lib /usr/include/x86_64-linux-gnu /usr/lib /lib/x86_64-linux-gnu /lib/../lib /usr/lib/x86_64-linux-gnu /usr/lib/../lib /lib /usr/local/lib /usr/lib/llvm-3.9/bin/../lib/clang/3.9.1/lib /usr/include/x86_64-linux-gnu /usr/lib libs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc so=so useshrplib=false libperl=libperl.a gnulibc_version='2.24' Dynamic Linking: dlsrc=dl_dlopen.xs dlext=so d_dlsymun=undef ccdlflags='-Wl,-E' cccdlflags='-fPIC' lddlflags='-shared -O0 -g -ggdb3 -fno-omit-frame-pointer -L/usr/local/lib -fstack-protector-strong' Locally applied patches: uncommitted-changes --- @INC for perl 5.27.1: lib /usr/local/lib/perl5/site_perl/5.26.0/x86_64-linux /usr/local/lib/perl5/site_perl/5.26.0 /usr/local/lib/perl5/5.26.0/x86_64-linux /usr/local/lib/perl5/5.26.0 --- Environment for perl 5.27.1: HOME=/home/afl LANG=en_US.UTF-8 LANGUAGE=en_US:en LC_CTYPE=en_US.UTF-8 LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=/home/afl/perlbrew/bin:/home/afl/perlbrew/perls/perl-5.24.1-dbg/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games PERLBREW_BASHRC_VERSION=0.78 PERLBREW_HOME=/home/afl/.perlbrew PERLBREW_MANPATH=/home/afl/perlbrew/perls/perl-5.24.1-dbg/man PERLBREW_PATH=/home/afl/perlbrew/bin:/home/afl/perlbrew/perls/perl-5.24.1-dbg/bin PERLBREW_PERL=perl-5.24.1-dbg PERLBREW_ROOT=/home/afl/perlbrew PERLBREW_VERSION=0.78 PERL_BADLANG (unset) SHELL=/usr/bin/zsh

This service is sponsored and maintained by Best Practical Solutions and runs on infrastructure.

For issues related to this RT instance (aka "perlbug"), please contact perlbug-admin at