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 program attached to this message to
cause an assertion failure​:

perl​: bsd_glob.c​:759​: int glob3(Char *, Char *, Char *, Char *, Char
*, Char *, Char *, glob_t *, size_t *)​: Assertion `restpattern <
restpattern_last' 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=0x7ffff7917040 "restpattern < restpattern_last",
file=0x7ffff7917003 "bsd_glob.c", line=759, function=<optimized out>)
at assert.c​:92
#3 0x00007ffff7c330f2 in __GI___assert_fail
(assertion=assertion@​entry=0x7ffff7917040 "restpattern <
restpattern_last",
  file=file@​entry=0x7ffff7917003 "bsd_glob.c", line=line@​entry=759,
function=function@​entry=0x7ffff791705f <__PRETTY_FUNCTION__.17683>
"glob3")
  at assert.c​:101
#4 0x00007ffff791323b in glob3 (pathbuf=pathbuf@​entry=0x7fffffff9cb0,
pathbuf_last=0x7fffffffbcae, pathend=pathend@​entry=0x7fffffff9cb0,
  pathend_last=pathend_last@​entry=0x7fffffffbcae,
pattern=0x7fffffff7cb0, restpattern=0x7fffffff9cae,
restpattern_last=0x7fffffff9cae,
  pglob=0x7fffffffdd60, limitp=0x7fffffff7ca8) at bsd_glob.c​:759
#5 0x00007ffff7912af3 in glob2 (pathbuf=pathbuf@​entry=0x7fffffff9cb0,
pathbuf_last=pathbuf_last@​entry=0x7fffffffbcae,
pathend=pathend@​entry=0x7fffffff9cb0,
  pathend_last=pathend_last@​entry=0x7fffffffbcae, pattern=<optimized
out>, pattern@​entry=0x7fffffff7cb0,
pattern_last=pattern_last@​entry=0x7fffffff9cae,
  pglob=0x7fffffffdd60, limitp=0x7fffffff7ca8) at bsd_glob.c​:732
#6 0x00007ffff79135fb in glob2 (limitp=0x7fffffff7ca8,
pglob=0x7fffffffdd60, pattern_last=0x7fffffff9cae,
pattern=0x7fffffff7cb0,
  pathend_last=0x7fffffffbcae, pathend=0x7fffffff9cb0,
pathbuf_last=0x7fffffffbcae, pathbuf=0x7fffffff9cb0) at bsd_glob.c​:668
#7 glob1 (limitp=0x7fffffff7ca8, pglob=0x7fffffffdd60,
pattern_last=0x7fffffff9cae, pattern=0x7fffffff7cb0) at bsd_glob.c​:650
#8 glob0 (pattern=pattern@​entry=0x7fffffffbd30,
pglob=pglob@​entry=0x7fffffffdd60) at bsd_glob.c​:584
#9 0x00007ffff7913a43 in globexp1 (pattern=0x7fffffffbd30,
pglob=pglob@​entry=0x7fffffffdd60) at bsd_glob.c​:316
#10 0x00007ffff7913b3e in bsd_glob
(pattern=pattern@​entry=0x5555559b6610 "0<0>", '0' <repeats 45 times>,
"'", '0' <repeats 150 times>...,
  flags=flags@​entry=11904, errfunc=errfunc@​entry=0x7ffff7913bf0
<errfunc>, pglob=pglob@​entry=0x7fffffffdd60) at bsd_glob.c​:292
#11 0x00007ffff7913ced in doglob (pattern=pattern@​entry=0x5555559b6610
"0<0>", '0' <repeats 45 times>, "'", '0' <repeats 150 times>...,
  flags=flags@​entry=11904) at Glob.xs​:49
#12 0x00007ffff7915a66 in csh_glob
(entries=entries@​entry=0x555555989710, pat=<optimized out>,
len=<optimized out>, is_utf8=<optimized out>) at Glob.xs​:282
#13 0x00007ffff79143a2 in iterate (globber=0x7ffff7915440 <csh_glob>)
at Glob.xs​:118
#14 0x000055555571d148 in Perl_pp_glob () at pp_sys.c​:364
#15 0x0000555555655792 in Perl_runops_debug () at dump.c​:2535
#16 0x00005555555c45f0 in S_run_body (oldscope=1) at perl.c​:2694
#17 perl_run (my_perl=<optimized out>) at perl.c​:2617
#18 0x000055555558d1d2 in main (argc=<optimized out>, argv=<optimized
out>, env=<optimized out>) at perlmain.c​:122

This is a regression between 5.18 and 5.20, bisect points to

commit 46a847d
Author​: David Mitchell <davem@​iabyn.com>
Date​: Wed Nov 13 12​:33​:40 2013 +0000

  File​::Glob​: silence some compiler warnings

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

From @dur-randir

0054

From @tonycoz

On Sun, 03 Mar 2019 11​:33​:07 -0800, randir wrote​:

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 v5.29.8-21-gde59f38ed9 built with afl and run
under libdislocator, I found the program attached to this message to
cause an assertion failure​:

perl​: bsd_glob.c​:759​: int glob3(Char *, Char *, Char *, Char *, Char
*, Char *, Char *, glob_t *, size_t *)​: Assertion `restpattern <
restpattern_last' failed.

I believe this is an error in the assertion.

The pattern in this case is exactly 4095 bytes long, you can reproduce this with​:

my $str = ("0" x 4094) . "?";
glob $str;

At the point of the call to glob3() restpattern points one past the end of the pattern (ie. at the terminating NUL for a simple glob) and restpattern_last points at the last byte in the buffer (*not* one past the end) ie. patbuf + MAXPATHLEN -1 (patbuf in glob0()).

So in this case they're equal and the assertion fails.

Tony

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