Assert fail with regex_sets error message, related to 125805

[p5pRT]

Migrated from rt.perl.org#126404 (status was 'resolved')

Searchable as RT126404$

[p5pRT]

From @dcollinsn

Greetings Porters,

I have compiled bleadperl with the afl-gcc compiler using​:

./Configure -Dusedevel -Dprefix='/usr/local/perl-afl' -Dcc='ccache afl-gcc' -Duselongdouble -Duse64bitall -Doptimize=-g -Uversiononly -Uman1dir -Uman3dir -des
AFL_HARDEN=1 make && make test

And then fuzzed the resulting binary using​:

AFL_NO_VAR_CHECK=1 afl-fuzz -i in -o out bin/perl @​@​

After reducing testcases using `afl-tmin` and performing additional minimization by hand, I have located the following testcase that triggers an assert fail in debugging builds of the perl interpreter. The testcase is the file​:

00./(?[!()])/

This is related to bug 125805, in fact I didn't file this sooner because I thought it was the same bug. However after that was fixed, this assert still fails on debugging builds. Non-debugging builds emit the warning but exit normally. Valgrind is clean except for the backtrace from the SIGABRT.

Output on debugging perl​:

The regex_sets feature is experimental in regex; marked by <-- HERE in m/(?[ <-- HERE !()])/ at -e line 1.
perl​: regcomp.c​:13810​: S_handle_regex_sets​: Assertion `(! ((current)->sv_flags & 0x00000100))' failed.
Aborted

**GDB**

(gdb) run
Starting program​: /home/dcollins/perldebug/perl -e 00./\(\?\[\!\(\)\]\)/
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
The regex_sets feature is experimental in regex; marked by <-- HERE in m/(?[ <-- HERE !()])/ at -e line 1.
perl​: regcomp.c​:13810​: S_handle_regex_sets​: Assertion `(! ((current)->sv_flags & 0x00000100))' failed.

Program received signal SIGABRT, Aborted.
0x00007ffff6cf4107 in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) bt
#0 0x00007ffff6cf4107 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1 0x00007ffff6cf54e8 in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2 0x00007ffff6ced226 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#3 0x00007ffff6ced2d2 in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6
#4 0x0000000000727779 in S_handle_regex_sets (pRExC_state=0x7fffffffdaa0, return_invlist=0xbd36, flagp=0x6, depth=4294967295,
  oregcomp_parse=0xfefefefefefefe00 <error​: Cannot access memory at address 0xfefefefefefefe00>) at regcomp.c​:13810
#5 0x00000000006ff63a in S_reg (pRExC_state=0x7fffffffdaa0, paren=48438, flagp=0x7fffffffd60c, depth=4294967295) at regcomp.c​:10494
#6 0x000000000072a375 in S_regatom (pRExC_state=0x7fffffffdaa0, flagp=0x7fffffffd79c, depth=4) at regcomp.c​:11804
#7 0x000000000073a836 in S_regpiece (depth=<optimized out>, flagp=<optimized out>, pRExC_state=<optimized out>) at regcomp.c​:10880
#8 S_regbranch (pRExC_state=0x7fffffffdaa0, flagp=0xbd36, first=-10116, depth=4294967295) at regcomp.c​:10805
#9 0x000000000075d007 in S_reg (pRExC_state=0x7fffffffdaa0, flagp=0x7fffffffd96c, depth=<optimized out>, paren=<optimized out>) at regcomp.c​:10550
#10 0x000000000079b9a9 in Perl_re_op_compile (patternp=0x1211f78, pat_count=0, expr=0x12080a8, eng=0xffffffffffffffff, old_re=0xe, is_bare_re=0x1211e40, orig_rx_flags=0,
  pm_flags=0) at regcomp.c​:6953
#11 0x00000000004e7ec2 in Perl_pmruntime (o=0x1211d88, expr=0x1211d48, repl=0x6, isreg=255, floor=7948352) at op.c​:5580
#12 0x000000000066f07d in Perl_yyparse (gramtype=18947464) at perly.y​:1032
#13 0x000000000053a659 in S_parse_body (env=env@​entry=0x0, xsinit=xsinit@​entry=0x42c060 <xs_init>) at perl.c​:2307
#14 0x00000000005423e3 in perl_parse (my_perl=<optimized out>, xsinit=xsinit@​entry=0x42c060 <xs_init>, argc=<optimized out>, argv=<optimized out>, env=env@​entry=0x0)
  at perl.c​:1634
#15 0x000000000042bc88 in main (argc=3, argv=0x7fffffffe338, env=0x7fffffffe358) at perlmain.c​:114
(gdb) info locals
No symbol table info available.
(gdb) f 4
#4 0x0000000000727779 in S_handle_regex_sets (pRExC_state=0x7fffffffdaa0, return_invlist=0xbd36, flagp=0x6, depth=4294967295,
  oregcomp_parse=0xfefefefefefefe00 <error​: Cannot access memory at address 0xfefefefefefefe00>) at regcomp.c​:13810
13810 assert(IS_OPERAND(current));
(gdb) info locals
stacked_operator = 0 '\000'
lhs = 0x1208120
rhs = 0x0
current = 0x1208108
start = 0
end = 0
stack = 0x12080d8
len = 0
save_end = 0x100 <error​: Cannot access memory at address 0x100>
save_parse = 0x0
re_debug_flags = 0
__PRETTY_FUNCTION__ = "S_handle_regex_sets"
(gdb) print *current
$1 = {sv_any = 0x12080f8, sv_refcnt = 1, sv_flags = 4353, sv_u = {svu_pv = 0x21 <error​: Cannot access memory at address 0x21>, svu_iv = 33, svu_uv = 33, svu_rv = 0x21,
  svu_rx = 0x21, svu_array = 0x21, svu_hash = 0x21, svu_gp = 0x21, svu_fp = 0x21}}
(gdb)

**PERL -V**

Summary of my perl5 (revision 5 version 23 subversion 4) configuration​:
  Commit id​: a7dba6f
  Platform​:
  osname=linux, osvers=3.16.0-4-amd64, archname=x86_64-linux-ld
  uname='linux nightshade64 3.16.0-4-amd64 #1 smp debian 3.16.7-ckt11-1+deb8u4 (2015-09-19) x86_64 gnulinux '
  config_args='-Dusedevel -Dprefix=/usr/local/perl-afl -Dcc=ccache afl-gcc -Duselongdouble -Duse64bitall -Doptimize=-g -Uversiononly -Uman1dir -Uman3dir -DDEBUGGING -DDEBUG_LEAKING_SCALARS -des'
  hint=recommended, useposix=true, d_sigaction=define
  useithreads=undef, usemultiplicity=undef
  use64bitint=define, use64bitall=define, uselongdouble=define
  usemymalloc=n, bincompat5005=undef
  Compiler​:
  cc='ccache afl-gcc', ccflags ='-fwrapv -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
  optimize='-g',
  cppflags='-fwrapv -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include'
  ccversion='', gccversion='4.9.2', 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='long double', nvsize=16, Off_t='off_t', lseeksize=8
  alignbytes=16, prototype=define
  Linker and Libraries​:
  ld='ccache afl-gcc', ldflags =' -fstack-protector-strong -L/usr/local/lib'
  libpth=/usr/local/lib /usr/lib/gcc/x86_64-linux-gnu/4.9/include-fixed /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
  libs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
  perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
  libc=libc-2.19.so, so=so, useshrplib=false, libperl=libperl.a
  gnulibc_version='2.19'
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
  cccdlflags='-fPIC', lddlflags='-shared -g -L/usr/local/lib -fstack-protector-strong'

Characteristics of this binary (from libperl)​:
  Compile-time options​: DEBUGGING HAS_TIMES PERLIO_LAYERS PERL_COPY_ON_WRITE
  PERL_DONT_CREATE_GVSV
  PERL_HASH_FUNC_ONE_AT_A_TIME_HARD PERL_MALLOC_WRAP
  PERL_PRESERVE_IVUV PERL_USE_DEVEL USE_64_BIT_ALL
  USE_64_BIT_INT USE_LARGE_FILES USE_LOCALE
  USE_LOCALE_COLLATE USE_LOCALE_CTYPE
  USE_LOCALE_NUMERIC USE_LOCALE_TIME USE_LONG_DOUBLE
  USE_PERLIO USE_PERL_ATOF
  Built under linux
  Compiled at Oct 15 2015 20​:45​:21
  @​INC​:
  /usr/local/perl-afl/lib/site_perl/5.23.4/x86_64-linux-ld
  /usr/local/perl-afl/lib/site_perl/5.23.4
  /usr/local/perl-afl/lib/5.23.4/x86_64-linux-ld
  /usr/local/perl-afl/lib/5.23.4
  .

[p5pRT]

@khwilliamson - Status changed from 'new' to 'open'

[p5pRT]

From @khwilliamson

Fixed by 174c990

Thank you for finding this, and the others
--
Karl Williamson

[p5pRT]

@khwilliamson - Status changed from 'open' to 'pending release'

[p5pRT]

From @khwilliamson

On Mon Oct 19 21​:30​:58 2015, khw wrote​:

Fixed by 174c990

Thank you for finding this, and the others

I'm sorry that commit number above is wrong (pasted from the wrong copy)
It should be 9457bb3

And the text of that commit message had a typo. It patches this ticket, #126406

Spotted by Steve Hay.

---

Karl Williamson

[p5pRT]

From @khwilliamson

Thank you for submitting this report. You have helped make Perl better.
 
With the release of Perl 5.24.0 on May 9, 2016, this and 149 other issues have been resolved.

Perl 5.24.0 may be downloaded via https://metacpan.org/release/RJBS/perl-5.24.0

[p5pRT]

@khwilliamson - Status changed from 'pending release' to 'resolved'