null ptr deref, segfault in Perl_pp_add pp_hot.c:597

[p5pRT]

Migrated from rt.perl.org#129164 (status was 'resolved')

Searchable as RT129164$

[p5pRT]

From @geeknik

Perl v5.25.4-27-gf16e7fa

./perl -e '$#b=()x0;0+splice@​b'

==95532==ERROR​: AddressSanitizer​: SEGV on unknown address 0x00000000000c (pc 0x0000008af771 bp 0x0c32000012d2 sp 0x7fff14ca0410 T0)
  #0 0x8af770 in Perl_pp_add /home/geeknik/perl/pp_hot.c​:597​:5
  #1 0x7f2623 in Perl_runops_debug /home/geeknik/perl/dump.c​:2234​:23
  #2 0x5a10c6 in S_run_body /home/geeknik/perl/perl.c​:2525​:2
  #3 0x5a10c6 in perl_run /home/geeknik/perl/perl.c​:2448
  #4 0x4de6cd in main /home/geeknik/perl/perlmain.c​:123​:9
  #5 0x7f8ae49a7b44 in __libc_start_main /build/glibc-uPj9cH/glibc-2.19/csu/libc-start.c​:287
  #6 0x4de33c in _start (/home/geeknik/perl/perl+0x4de33c)

AddressSanitizer can not provide additional info.
SUMMARY​: AddressSanitizer​: SEGV /home/geeknik/perl/pp_hot.c​:597 Perl_pp_add
==95532==ABORTING

Program received signal SIGSEGV, Segmentation fault.
0x00000000008af7df in Perl_pp_add () at pp_hot.c​:597
597 tryAMAGICbin_MG(add_amg, AMGf_assign|AMGf_numeric);
(gdb) bt
#0 0x00000000008af7df in Perl_pp_add () at pp_hot.c​:597
#1 0x00000000007f26a4 in Perl_runops_debug () at dump.c​:2234
#2 0x00000000005a10c7 in S_run_body (oldscope=<optimized out>) at perl.c​:2525
#3 perl_run (my_perl=<optimized out>) at perl.c​:2448
#4 0x00000000004de6ce in main (argc=<optimized out>, argv=<optimized out>, env=<optimized out>) at perlmain.c​:123

==20742== Invalid read of size 4
==20742== at 0x500FC3​: Perl_pp_add (pp_hot.c​:597)
==20742== by 0x4D6261​: Perl_runops_debug (dump.c​:2234)
==20742== by 0x452E96​: S_run_body (perl.c​:2525)
==20742== by 0x452E96​: perl_run (perl.c​:2448)
==20742== by 0x421834​: main (perlmain.c​:123)
==20742== Address 0xc is not stack'd, malloc'd or (recently) free'd
==20742==
==20742==
==20742== Process terminating with default action of signal 11 (SIGSEGV)
==20742== Access not within mapped region at address 0xC
==20742== at 0x500FC3​: Perl_pp_add (pp_hot.c​:597)
==20742== by 0x4D6261​: Perl_runops_debug (dump.c​:2234)
==20742== by 0x452E96​: S_run_body (perl.c​:2525)
==20742== by 0x452E96​: perl_run (perl.c​:2448)
==20742== by 0x421834​: main (perlmain.c​:123)
==20742== If you believe this happened as a result of a stack
==20742== overflow in your program's main thread (unlikely but
==20742== possible), you can try to increase the size of the
==20742== main thread stack using the --main-stacksize= flag.
==20742== The main thread stack size used in this run was 8388608.
Segmentation fault

[p5pRT]

From @cpansprout

Now fixed in 92b69f6.

--

Father Chrysostomos

[p5pRT]

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

[p5pRT]

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

[p5pRT]

From @khwilliamson

Thank you for filing this report. You have helped make Perl better.

With the release today of Perl 5.26.0, this and 210 other issues have been
resolved.

Perl 5.26.0 may be downloaded via​:
https://metacpan.org/release/XSAWYERX/perl-5.26.0

If you find that the problem persists, feel free to reopen this ticket.

[p5pRT]

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