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Report information
Id: 126480
Status: resolved
Priority: 0/
Queue: perl5

Owner: Nobody
Requestors: dcollinsn [at] gmail.com
Cc:
AdminCc:

Operating System: (no value)
PatchStatus: (no value)
Severity: low
Type: unknown
Perl Version: (no value)
Fixed In: (no value)

Attachments
0001-perl-126480-pipe-doesn-t-need-the-assertions.patch



Subject: Assert fail w/o other symptoms - pp_sys.c:690 Perl_pp_pipe_op when first arg to pipe is definitely not a filehandle
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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 perls without any other symptoms in the normal perl interpreter. The testcase is the file: pipe$$5,0 dcollins@nightshade64:/usr/local/perl-afl$ ./bin/perl -e 'pipe$$5,0' perl: pp_sys.c:690: Perl_pp_pipe_op: Assertion `((((rgv)->sv_flags & (0x00004000|0x00008000)) == 0x00008000) && (((svtype)((rgv)->sv_flags & 0xff)) == SVt_PVGV || ((svtype)((rgv)->sv_flags & 0xff)) == SVt_PVLV))' failed. Aborted The output with a normal perl is the expected error: dcollins@nightshade64:/usr/local/perl-afl$ ~/perl/perl -e 'pipe$$5,0' Bad symbol for filehandle at -e line 1. **GDB** (gdb) run Starting program: /usr/local/perl-afl/bin/perl -e pipe\$\$5,0 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". bperl: pp_sys.c:690: Perl_pp_pipe_op: Assertion `((((rgv)->sv_flags & (0x00004000|0x00008000)) == 0x00008000) && (((svtype)((rgv)->sv_flags & 0xff)) == SVt_PVGV || ((svtype)((rgv)->sv_flags & 0xff)) == SVt_PVLV))' failed. Program received signal SIGABRT, Aborted. 0x00007ffff6cf4107 in raise () from /lib/x86_64-linux-gnu/libc.so.6 (gdb) bt #0 0x00007ffff6cf4107 in raise () from /lib/x86_64-linux-gnu/libc.so.6 #1 0x00007ffff6cf54e8 in abort () from /lib/x86_64-linux-gnu/libc.so.6 #2 0x00007ffff6ced226 in ?? () from /lib/x86_64-linux-gnu/libc.so.6 #3 0x00007ffff6ced2d2 in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6 #4 0x0000000000b95275 in Perl_pp_pipe_op () at pp_sys.c:690 #5 0x00000000007bdf7f in Perl_runops_debug () at dump.c:2224 #6 0x0000000000527fc1 in S_run_body (oldscope=1) at perl.c:2459 #7 perl_run (my_perl=<optimized out>) at perl.c:2382 #8 0x0000000000428b18 in main (argc=3, argv=0x7fffffffe658, env=0x7fffffffe678) at perlmain.c:116 (gdb) f 4 #4 0x0000000000b95275 in Perl_pp_pipe_op () at pp_sys.c:690 690 assert (isGV_with_GP(rgv)); (gdb) info locals sp = 0x11a8a20 rstio = <optimized out> wstio = <optimized out> fd = {0, 0} wgv = 0x11ba5a0 rgv = 0x11a30a0 <PL_sv_undef> __PRETTY_FUNCTION__ = "Perl_pp_pipe_op" (gdb) q A debugging session is active. Inferior 1 [process 4065] will be killed. Quit anyway? (y or n) y **VALGRIND** dcollins@nightshade64:/usr/local/perl-afl$ valgrind ./bin/perl -e 'pipe$$5,0' ==11068== Memcheck, a memory error detector ==11068== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al. ==11068== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info ==11068== Command: ./bin/perl -e pipe$$5,0 ==11068== perl: pp_sys.c:690: Perl_pp_pipe_op: Assertion `((((rgv)->sv_flags & (0x00004000|0x00008000)) == 0x00008000) && (((svtype)((rgv)->sv_flags & 0xff)) == SVt_PVGV || ((svtype)((rgv)->sv_flags & 0xff)) == SVt_PVLV))' failed. ==11068== ==11068== Process terminating with default action of signal 6 (SIGABRT) ==11068== at 0x5BDC107: raise (raise.c:56) ==11068== by 0x5BDD4E7: abort (abort.c:89) ==11068== by 0x5BD5225: __assert_fail_base (assert.c:92) ==11068== by 0x5BD52D1: __assert_fail (assert.c:101) ==11068== by 0xB95274: Perl_pp_pipe_op (pp_sys.c:690) ==11068== by 0x7BDF7E: Perl_runops_debug (dump.c:2224) ==11068== by 0x527FC0: S_run_body (perl.c:2459) ==11068== by 0x527FC0: perl_run (perl.c:2382) ==11068== by 0x428B17: main (perlmain.c:116) ==11068== ==11068== HEAP SUMMARY: ==11068== in use at exit: 110,234 bytes in 542 blocks ==11068== total heap usage: 681 allocs, 139 frees, 134,449 bytes allocated ==11068== ==11068== LEAK SUMMARY: ==11068== definitely lost: 176 bytes in 1 blocks ==11068== indirectly lost: 1,974 bytes in 20 blocks ==11068== possibly lost: 0 bytes in 0 blocks ==11068== still reachable: 108,084 bytes in 521 blocks ==11068== suppressed: 0 bytes in 0 blocks ==11068== Rerun with --leak-check=full to see details of leaked memory ==11068== ==11068== For counts of detected and suppressed errors, rerun with: -v ==11068== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0) Aborted **PERL -V** dcollins@nightshade64:/usr/local/perl-afl$ ./bin/perl -V Summary of my perl5 (revision 5 version 23 subversion 5) configuration: Commit id: 7195e5da55a40d15e29ad80562668bdd6895441f 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 -DPERL_POISON -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='5.2.0', 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/local/lib/gcc/x86_64-unknown-linux-gnu/5.2.0/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 22 2015 15:44:40 @INC: /usr/local/perl-afl/lib/site_perl/5.23.5/x86_64-linux-ld /usr/local/perl-afl/lib/site_perl/5.23.5 /usr/local/perl-afl/lib/5.23.5/x86_64-linux-ld /usr/local/perl-afl/lib/5.23.5 /usr/local/perl-afl/lib/site_perl/5.23.4 /usr/local/perl-afl/lib/site_perl .
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On Wed Oct 28 19:59:00 2015, dcollinsn@gmail.com wrote: Show quoted text
> 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 perls without any other symptoms > in the normal perl interpreter. The testcase is the file: > > pipe$$5,0 > > dcollins@nightshade64:/usr/local/perl-afl$ ./bin/perl -e 'pipe$$5,0' > perl: pp_sys.c:690: Perl_pp_pipe_op: Assertion `((((rgv)->sv_flags & > (0x00004000|0x00008000)) == 0x00008000) && (((svtype)((rgv)->sv_flags > & 0xff)) == SVt_PVGV || ((svtype)((rgv)->sv_flags & 0xff)) == > SVt_PVLV))' failed. > Aborted > > The output with a normal perl is the expected error: > > dcollins@nightshade64:/usr/local/perl-afl$ ~/perl/perl -e 'pipe$$5,0' > Bad symbol for filehandle at -e line 1.
I suspect the assertions are incorrect here. S_rv2gv returns &PL_sv_undef when it can't turn the value into something resembling a GV, and the GvIOn() macro can handle that (by croaking). So the assertions would be something like: diff --git a/pp_sys.c b/pp_sys.c index 373590f..8589413 100644 --- a/pp_sys.c +++ b/pp_sys.c @@ -695,8 +695,10 @@ PP(pp_pipe_op) GV * const wgv = MUTABLE_GV(POPs); GV * const rgv = MUTABLE_GV(POPs); - assert (isGV_with_GP(rgv)); - assert (isGV_with_GP(wgv)); + /* rv2gv pushes PL_sv_undef when it can't make a GV, and GvIOn() properly croaks + when it's supplied with such */ + assert ((SV*)rgv == &PL_sv_undef || isGV_with_GP(rgv)); + assert ((SV*)wgv == &PL_sv_undef || isGV_with_GP(wgv)); rstio = GvIOn(rgv); if (IoIFP(rstio)) do_close(rgv, FALSE); The other I/O "openers" (socket, sysopen, open) either call GvIOn() or do a non-assertion test of isGV_with_GP(). Possibly the assertions should just be removed. Tony
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On Wed Oct 28 20:49:47 2015, tonyc wrote: Show quoted text
> Possibly the assertions should just be removed.
Like in the attached patch. Tony
Subject: 0001-perl-126480-pipe-doesn-t-need-the-assertions.patch
From 992ebee3f63e16317109eca1eb0d76925c594593 Mon Sep 17 00:00:00 2001 From: Tony Cook <tony@develop-help.com> Date: Mon, 2 Nov 2015 17:22:25 +1100 Subject: [perl 126480] pipe() doesn't need the assertions GvIOn() already performs the checks and produces a nice error message. --- MANIFEST | 1 + pp_sys.c | 2 -- t/lib/croak/pp_sys | 16 ++++++++++++++++ 3 files changed, 17 insertions(+), 2 deletions(-) create mode 100644 t/lib/croak/pp_sys diff --git a/MANIFEST b/MANIFEST index f07488f..ed47673 100644 --- a/MANIFEST +++ b/MANIFEST @@ -5043,6 +5043,7 @@ t/lib/croak/op Test croak calls from op.c t/lib/croak/pp Test croak calls from pp.c t/lib/croak/pp_ctl Test croak calls from pp_ctl.c t/lib/croak/pp_hot Test croak calls from pp_hot.c +t/lib/croak/pp_sys Test croak calls from pp_sys.c t/lib/croak.t Test calls to Perl_croak() in the C source. t/lib/croak/toke Test croak calls from toke.c t/lib/cygwin.t Builtin cygwin function tests diff --git a/pp_sys.c b/pp_sys.c index 373590f..15b4d8b 100644 --- a/pp_sys.c +++ b/pp_sys.c @@ -695,8 +695,6 @@ PP(pp_pipe_op) GV * const wgv = MUTABLE_GV(POPs); GV * const rgv = MUTABLE_GV(POPs); - assert (isGV_with_GP(rgv)); - assert (isGV_with_GP(wgv)); rstio = GvIOn(rgv); if (IoIFP(rstio)) do_close(rgv, FALSE); diff --git a/t/lib/croak/pp_sys b/t/lib/croak/pp_sys new file mode 100644 index 0000000..001baa3 --- /dev/null +++ b/t/lib/croak/pp_sys @@ -0,0 +1,16 @@ +__END__ +# pp_sys.c +# NAME pipe() croaks on bad left side [perl #126480] +# SKIP ? use Config; !$Config{d_pipe} && "No pipe() available" +my $fh; +pipe($$5, $fh) +EXPECT +Bad symbol for filehandle at - line 3. +######## +# NAME pipe() croaks on bad left side [perl #126480] +# SKIP ? use Config; !$Config{d_pipe} && "No pipe() available" +my $fh; +pipe($fh, $$5) +EXPECT +Bad symbol for filehandle at - line 2. +######## -- 2.1.4
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On Sun Nov 01 22:23:07 2015, tonyc wrote: Show quoted text
> On Wed Oct 28 20:49:47 2015, tonyc wrote:
> > Possibly the assertions should just be removed.
> > Like in the attached patch.
Applied as e8c18a8486f7e900511cc2df8d2617ceab9ce437, with a fix for the NAME line of the second test. Tony
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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


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