Crashes caused by \N{} + codeblock in regex

[p5pRT]

Migrated from rt.perl.org#133990 (status was 'open')

Searchable as RT133990$

[p5pRT]

From @dur-randir

Created by @dur-randir

While fuzzing perl v5.29.9-63-g2496d8f3f7 built with afl and run
under libdislocator, I found the following programs

qr/(?{})\N{}/;while(my($0)=0){}
qr/(?{})\N{}/;while(my($0)){}
qr/(?{})\N{}/;

to cause different assertion failures and/or straight out crashes.
This happens since \N{} fatalization by

commit be332ba
Author​: Karl Williamson <khw@​cpan.org>
Date​: Thu Mar 2 11​:31​:36 2017 -0700

  Fatalize \N{}

  This has been deprecated, scheduled to be fatal now.

Perl Info

Flags:
    category=core
    severity=low

Site configuration information for perl 5.29.9:

Configured by dur-randir at Wed Feb 27 14:51:01 MSK 2019.

Summary of my perl5 (revision 5 version 29 subversion 9) configuration:
  Commit id: c1e47bad34ce1d9c84ed57c9b8978bcbd5a02e98
  Platform:
    osname=darwin
    osvers=13.4.0
    archname=darwin-thread-multi-2level
    uname='darwin isengard.local 13.4.0 darwin kernel version 13.4.0:
mon jan 11 18:17:34 pst 2016; root:xnu-2422.115.15~1release_x86_64
x86_64 '
    config_args='-de -Dusedevel -DDEBUGGING -Dusethreads'
    hint=recommended
    useposix=true
    d_sigaction=define
    useithreads=define
    usemultiplicity=define
    use64bitint=define
    use64bitall=define
    uselongdouble=undef
    usemymalloc=n
    default_inc_excludes_dot=define
    bincompat5005=undef
  Compiler:
    cc='cc'
    ccflags ='-fno-common -DPERL_DARWIN -mmacosx-version-min=10.9
-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector
-I/usr/local/include -DPERL_USE_SAFE_PUTENV'
    optimize='-O3 -g'
    cppflags='-fno-common -DPERL_DARWIN -mmacosx-version-min=10.9
-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector
-I/usr/local/include'
    ccversion=''
    gccversion='4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.56)'
    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='cc'
    ldflags =' -mmacosx-version-min=10.9 -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0/lib
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib
/usr/lib
    libs=-lpthread -lgdbm -ldbm -ldl -lm -lutil -lc
    perllibs=-lpthread -ldl -lm -lutil -lc
    libc=
    so=dylib
    useshrplib=false
    libperl=libperl.a
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_dlopen.xs
    dlext=bundle
    d_dlsymun=undef
    ccdlflags=' '
    cccdlflags=' '
    lddlflags=' -mmacosx-version-min=10.9 -bundle -undefined
dynamic_lookup -L/usr/local/lib -fstack-protector'



@INC for perl 5.29.9:
    lib
    /usr/local/lib/perl5/site_perl/5.29.9/darwin-thread-multi-2level
    /usr/local/lib/perl5/site_perl/5.29.9
    /usr/local/lib/perl5/5.29.9/darwin-thread-multi-2level
    /usr/local/lib/perl5/5.29.9


Environment for perl 5.29.9:
    DYLD_LIBRARY_PATH (unset)
    HOME=/Users/dur-randir
    LANG=en_US.UTF-8
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/Users/dur-randir/perlbrew/bin:/Users/dur-randir/perlbrew/perls/perl-5.22.1/bin:/usr/local/bin:/usr/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/texbin
    PERLBREW_HOME=/Users/dur-randir/.perlbrew
    PERLBREW_MANPATH=/Users/dur-randir/perlbrew/perls/perl-5.22.1/man
    PERLBREW_PATH=/Users/dur-randir/perlbrew/bin:/Users/dur-randir/perlbrew/perls/perl-5.22.1/bin
    PERLBREW_PERL=perl-5.22.1
    PERLBREW_ROOT=/Users/dur-randir/perlbrew
    PERLBREW_SHELLRC_VERSION=0.84
    PERLBREW_VERSION=0.84
    PERL_BADLANG (unset)
    SHELL=/usr/local/bin/zsh

[p5pRT]

From @khwilliamson

On 4/5/19 11​:11 AM, Sergey Aleynikov (via RT) wrote​:

# New Ticket Created by Sergey Aleynikov
# Please include the string​: [perl #133990]
# in the subject line of all future correspondence about this issue.
# <URL​: https://rt-archive.perl.org/perl5/Ticket/Display.html?id=133990 >

This is a bug report for perl from sergey.aleynikov@​gmail.com,
generated with the help of perlbug 1.41 running under perl 5.29.9.

-----------------------------------------------------------------
[Please describe your issue here]

While fuzzing perl v5.29.9-63-g2496d8f3f7 built with afl and run
under libdislocator, I found the following programs

qr/(?{})\N{}/;while(my($0)=0){}
qr/(?{})\N{}/;while(my($0)){}
qr/(?{})\N{}/;

I looked at the final one in detail. What is happening here is that the
\N{} is an error, and it sets a flag to indicate to not try to compile
the pattern, but parsing continues to try to find other errors. At some
point later, op.c line 827 sees that flag and returns 'o' without
proceeding. Later an assertion fails in op_free(). My guess is that
it's something that op_free is counting on that got skipped when line
827 returned from its function early.

But I'm hoping someone more familiar with this area of the core will
look at it.

to cause different assertion failures and/or straight out crashes.
This happens since \N{} fatalization by

commit be332ba
Author​: Karl Williamson <khw@​cpan.org>
Date​: Thu Mar 2 11​:31​:36 2017 -0700

 Fatalize \\N\{\}

 This has been deprecated\, scheduled to be fatal now\.

[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags​:
category=core
severity=low
---
Site configuration information for perl 5.29.9​:

Configured by dur-randir at Wed Feb 27 14​:51​:01 MSK 2019.

Summary of my perl5 (revision 5 version 29 subversion 9) configuration​:
Commit id​: c1e47ba
Platform​:
osname=darwin
osvers=13.4.0
archname=darwin-thread-multi-2level
uname='darwin isengard.local 13.4.0 darwin kernel version 13.4.0​:
mon jan 11 18​:17​:34 pst 2016; root​:xnu-2422.115.15~1release_x86_64
x86_64 '
config_args='-de -Dusedevel -DDEBUGGING -Dusethreads'
hint=recommended
useposix=true
d_sigaction=define
useithreads=define
usemultiplicity=define
use64bitint=define
use64bitall=define
uselongdouble=undef
usemymalloc=n
default_inc_excludes_dot=define
bincompat5005=undef
Compiler​:
cc='cc'
ccflags ='-fno-common -DPERL_DARWIN -mmacosx-version-min=10.9
-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector
-I/usr/local/include -DPERL_USE_SAFE_PUTENV'
optimize='-O3 -g'
cppflags='-fno-common -DPERL_DARWIN -mmacosx-version-min=10.9
-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector
-I/usr/local/include'
ccversion=''
gccversion='4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.56)'
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='cc'
ldflags =' -mmacosx-version-min=10.9 -fstack-protector -L/usr/local/lib'
libpth=/usr/local/lib
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0/lib
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib
/usr/lib
libs=-lpthread -lgdbm -ldbm -ldl -lm -lutil -lc
perllibs=-lpthread -ldl -lm -lutil -lc
libc=
so=dylib
useshrplib=false
libperl=libperl.a
gnulibc_version=''
Dynamic Linking​:
dlsrc=dl_dlopen.xs
dlext=bundle
d_dlsymun=undef
ccdlflags=' '
cccdlflags=' '
lddlflags=' -mmacosx-version-min=10.9 -bundle -undefined
dynamic_lookup -L/usr/local/lib -fstack-protector'

---
@​INC for perl 5.29.9​:
lib
/usr/local/lib/perl5/site_perl/5.29.9/darwin-thread-multi-2level
/usr/local/lib/perl5/site_perl/5.29.9
/usr/local/lib/perl5/5.29.9/darwin-thread-multi-2level
/usr/local/lib/perl5/5.29.9

---
Environment for perl 5.29.9​:
DYLD_LIBRARY_PATH (unset)
HOME=/Users/dur-randir
LANG=en_US.UTF-8
LANGUAGE (unset)
LD_LIBRARY_PATH (unset)
LOGDIR (unset)
PATH=/Users/dur-randir/perlbrew/bin​:/Users/dur-randir/perlbrew/perls/perl-5.22.1/bin​:/usr/local/bin​:/usr/local/sbin​:/usr/bin​:/bin​:/usr/sbin​:/sbin​:/usr/texbin
PERLBREW_HOME=/Users/dur-randir/.perlbrew
PERLBREW_MANPATH=/Users/dur-randir/perlbrew/perls/perl-5.22.1/man
PERLBREW_PATH=/Users/dur-randir/perlbrew/bin​:/Users/dur-randir/perlbrew/perls/perl-5.22.1/bin
PERLBREW_PERL=perl-5.22.1
PERLBREW_ROOT=/Users/dur-randir/perlbrew
PERLBREW_SHELLRC_VERSION=0.84
PERLBREW_VERSION=0.84
PERL_BADLANG (unset)
SHELL=/usr/local/bin/zsh

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'