Assertion failure in Perl_pp_sort/S_POPMARK

[p5pRT]

Migrated from rt.perl.org#133883 (status was 'new')

Searchable as RT133883$

[p5pRT]

From @dur-randir

Created by @dur-randir

While fuzzing perl v5.29.8-21-gde59f38ed9 built with afl and run
under libdislocator, I found the following program

\(sort {0} 0, 0 .. "r")

to cause an assertion failure​:

perl​: ./inline.h​:172​: I32 S_POPMARK()​: Assertion `(PL_markstack_ptr >
PL_markstack) || !"MARK underflow"' failed.

GDB stack trace is following​:

#0 __GI_raise (sig=sig@​entry=6) at ../sysdeps/unix/sysv/linux/raise.c​:50
#1 0x00007ffff7c25535 in __GI_abort () at abort.c​:79
#2 0x00007ffff7c2540f in __assert_fail_base (fmt=0x7ffff7d87ee0
"%s%s%s​:%u​: %s%sAssertion `%s' failed.\n%n",
  assertion=0x555555af4448 "(PL_markstack_ptr > PL_markstack) ||
!\"MARK underflow\"", file=0x555555af43f0 "inline.h", line=172,
function=<optimized out>)
  at assert.c​:92
#3 0x00007ffff7c330f2 in __GI___assert_fail (assertion=0x555555af4448
"(PL_markstack_ptr > PL_markstack) || !\"MARK underflow\"",
  file=0x555555af43f0 "inline.h", line=172, function=0x555555af4b88
<__PRETTY_FUNCTION__.17049> "S_POPMARK") at assert.c​:101
#4 0x00005555559030bf in S_POPMARK () at inline.h​:172
#5 0x00005555559049fd in Perl_pp_sort () at pp_sort.c​:798
#6 0x00005555556f692d in Perl_runops_debug () at dump.c​:2537
#7 0x0000555555907adb in S_sortcv (a=0x555555b4b0b0,
b=0x555555b40e60) at pp_sort.c​:1132
#8 0x0000555555903b3b in dynprep (list1=0x555555b4a298,
list2=0x7fffffffc5a0, nmemb=2, cmp=0x555555907718 <S_sortcv>) at
pp_sort.c​:197
#9 0x0000555555903fde in Perl_sortsv_flags (base=0x555555b4a298,
nmemb=2, cmp=0x555555907718 <S_sortcv>, flags=0) at pp_sort.c​:388
#10 0x0000555555906daa in Perl_pp_sort () at pp_sort.c​:1014
#11 0x00005555556f692d in Perl_runops_debug () at dump.c​:2537
#12 0x0000555555907adb in S_sortcv (a=0x555555b4b0b0,
b=0x555555b26728) at pp_sort.c​:1132
#13 0x0000555555903b3b in dynprep (list1=0x555555b28da8,
list2=0x7fffffffd530, nmemb=2, cmp=0x555555907718 <S_sortcv>) at
pp_sort.c​:197
#14 0x0000555555903fde in Perl_sortsv_flags (base=0x555555b28da8,
nmemb=2, cmp=0x555555907718 <S_sortcv>, flags=0) at pp_sort.c​:388
#15 0x0000555555906daa in Perl_pp_sort () at pp_sort.c​:1014
#16 0x00005555556f692d in Perl_runops_debug () at dump.c​:2537
#17 0x00005555555da124 in S_run_body (oldscope=1) at perl.c​:2692
#18 0x00005555555d96a2 in perl_run (my_perl=0x555555b24260) at perl.c​:2615
#19 0x000055555558e12e in main (argc=3, argv=0x7fffffffe1c8,
env=0x7fffffffe1e8) at perlmain.c​:127

This is a regression between 5.24 and 5.26, bisect points to

commit b369834
Author​: Zefram <zefram@​fysh.org>
Date​: Fri Jan 27 03​:55​:46 2017 +0000

  fix range op under aborted constant folding

Perl Info

Flags:
    category=core
    severity=medium

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