From f7e5d464be66b2023d9ebcd06b963e0896cda78f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppi...@redhat.com>
Date: Mon, 19 Jun 2017 13:45:43 +0200
Subject: Fix a conditional jump on uninitilized memory in re_intuit_start()
---
...-call-Perl_fbm_instr-with-negative-length.patch | 116 +++++++++++++++++++++
perl.spec | 9 +-
2 files changed, 124 insertions(+), 1 deletion(-)
create mode 100644
perl-5.26.0-don-t-call-Perl_fbm_instr-with-negative-length.patch
diff --git a/perl-5.26.0-don-t-call-Perl_fbm_instr-with-negative-length.patch
b/perl-5.26.0-don-t-call-Perl_fbm_instr-with-negative-length.patch
new file mode 100644
index 0000000..672ffbb
--- /dev/null
+++ b/perl-5.26.0-don-t-call-Perl_fbm_instr-with-negative-length.patch
@@ -0,0 +1,116 @@
+From 10e784017784a8c1b1835b04026f8948eb502e50 Mon Sep 17 00:00:00 2001
+From: David Mitchell <da...@iabyn.com>
+Date: Fri, 16 Jun 2017 15:46:19 +0100
+Subject: [PATCH] don't call Perl_fbm_instr() with negative length
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Ported to 5.26.0:
+
+commit bb152a4b442f7718fd37d32cc558be675e8ae1ae
+Author: David Mitchell <da...@iabyn.com>
+Date: Fri Jun 16 15:46:19 2017 +0100
+
+ don't call Perl_fbm_instr() with negative length
+
+ RT #131575
+
+ re_intuit_start() could calculate a maximum end position less than the
+ current start position. This used to get rejected by fbm_intr(), until
+ v5.23.3-110-g147f21b, which made fbm_intr() faster and removed unnecessary
+ checks.
+
+ This commits fixes re_intuit_start(), and adds an assert to fbm_intr().
+
+Signed-off-by: Petr Písař <ppi...@redhat.com>
+---
+ regexec.c | 17 +++++++++++------
+ t/re/pat.t | 13 ++++++++++++-
+ util.c | 2 ++
+ 3 files changed, 25 insertions(+), 7 deletions(-)
+
+diff --git a/regexec.c b/regexec.c
+index 35b88d7..4e82bc2 100644
+--- a/regexec.c
++++ b/regexec.c
+@@ -126,13 +126,16 @@ static const char* const
non_utf8_target_but_utf8_required
+ (U8*)(off >= 0 ? reginfo->strend : reginfo->strbeg)) \
+ : (U8*)(pos + off))
+
+-#define HOPBACKc(pos, off) \
+- (char*)(reginfo->is_utf8_target \
+- ? reghopmaybe3((U8*)pos, (SSize_t)0-off, (U8*)(reginfo->strbeg)) \
+- : (pos - off >= reginfo->strbeg) \
+- ? (U8*)pos - off \
++/* like HOPMAYBE3 but backwards. lim must be +ve. Returns NULL on overshoot */
++#define HOPBACK3(pos, off, lim) \
++ (reginfo->is_utf8_target \
++ ? reghopmaybe3((U8*)pos, (SSize_t)0-off, (U8*)(lim)) \
++ : (pos - off >= lim) \
++ ? (U8*)pos - off \
+ : NULL)
+
++#define HOPBACKc(pos, off) ((char*)HOPBACK3(pos, off, reginfo->strbeg))
++
+ #define HOP3(pos,off,lim) (reginfo->is_utf8_target ? reghop3((U8*)(pos),
off, (U8*)(lim)) : (U8*)(pos + off))
+ #define HOP3c(pos,off,lim) ((char*)HOP3(pos,off,lim))
+
+@@ -884,7 +887,9 @@ Perl_re_intuit_start(pTHX_
+ (IV)prog->check_end_shift);
+ });
+
+- end_point = HOP3(strend, -end_shift, strbeg);
++ end_point = HOPBACK3(strend, end_shift, rx_origin);
++ if (!end_point)
++ goto fail_finish;
+ start_point = HOPMAYBE3(rx_origin, start_shift, end_point);
+ if (!start_point)
+ goto fail_finish;
+diff --git a/t/re/pat.t b/t/re/pat.t
+index 16bfc8e..2510eab 100644
+--- a/t/re/pat.t
++++ b/t/re/pat.t
+@@ -23,7 +23,7 @@ BEGIN {
+ skip_all('no re module') unless defined &DynaLoader::boot_DynaLoader;
+ skip_all_without_unicode_tables();
+
+-plan tests => 837; # Update this when adding/deleting tests.
++plan tests => 838; # Update this when adding/deleting tests.
+
+ run_tests() unless caller;
+
+@@ -1911,6 +1911,17 @@ EOP
+ # [perl #129281] buffer write overflow, detected by ASAN, valgrind
+ fresh_perl_is('/0(?0)|^*0(?0)|^*(^*())0|/', '', {}, "don't bump
whilem_c too much");
+ }
++
++ {
++ # RT #131575 intuit skipping back from the end to find the highest
++ # possible start point, was potentially hopping back beyond pos()
++ # and crashing by calling fbm_instr with a negative length
++
++ my $text = "=t=\x{5000}";
++ pos($text) = 3;
++ ok(scalar($text !~ m{(~*=[a-z]=)}g), "RT #131575");
++ }
++
+ } # End of sub run_tests
+
+ 1;
+diff --git a/util.c b/util.c
+index f1b92a9..69763bc 100644
+--- a/util.c
++++ b/util.c
+@@ -816,6 +816,8 @@ Perl_fbm_instr(pTHX_ unsigned char *big, unsigned char
*bigend, SV *littlestr, U
+
+ PERL_ARGS_ASSERT_FBM_INSTR;
+
++ assert(bigend >= big);
++
+ if ((STRLEN)(bigend - big) < littlelen) {
+ if ( tail
+ && ((STRLEN)(bigend - big) == littlelen - 1)
+--
+2.9.4
+
diff --git a/perl.spec b/perl.spec
index 4528650..8938e4c 100644
--- a/perl.spec
+++ b/perl.spec
@@ -165,6 +165,10 @@ Patch37:
perl-5.27.0-perl-131526-don-t-go-beyond-the-end-of-the-NUL-in-my
# "perl -S", RT#129183, in upstream after 5.27.0
Patch38:
perl-5.27.0-perl-129183-don-t-treat-as-an-escape-in-PATH-for-S.patch
+# Fix a conditional jump on uninitilized memory in re_intuit_start(),
+# RT#131575, in upstream after 5.27.0
+Patch39:
perl-5.26.0-don-t-call-Perl_fbm_instr-with-negative-length.patch
+
# Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048
Patch200:
perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch
@@ -2821,6 +2825,7 @@ Perl extension for Version Objects
%patch36 -p1
%patch37 -p1
%patch38 -p1
+%patch39 -p1
%patch200 -p1
%patch201 -p1
@@ -2848,6 +2853,7 @@ perl -x patchlevel.h \
'Fedora Patch36: Fix glob UTF-8 flag on a glob reassignment (RT#131263)' \
'Fedora Patch37: Fix a buffer overflow in my_atof2() (RT#131526)' \
'Fedora Patch38: Fix handling backslashes in PATH environment variable
when executing "perl -S" (RT#129183)' \
+ 'Fedora Patch39: Fix a conditional jump on uninitilized memory in
re_intuit_start() (RT#131575)' \
'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on
Linux' \
'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \
%{nil}
@@ -5130,7 +5136,7 @@ popd
# Old changelog entries are preserved in CVS.
%changelog
-* Fri Jun 16 2017 Petr Pisar <ppi...@redhat.com> - 4:5.26.0-394
+* Mon Jun 19 2017 Petr Pisar <ppi...@redhat.com> - 4:5.26.0-394
- Make File::Glob more resistant against degenerative matching (RT#131211)
- Fix a crash when calling a subroutine from a stash (RT#131085)
- Fix an improper cast of a negative integer to an unsigned 8-bit type
(RT#131190)
@@ -5139,6 +5145,7 @@ popd
- Fix a buffer overflow in my_atof2() (RT#131526)
- Fix handling backslashes in PATH environment variable when executing
"perl -S" (RT#129183)
+- Fix a conditional jump on uninitilized memory in re_intuit_start()
(RT#131575)
* Tue Jun 06 2017 Jitka Plesnikova <jples...@redhat.com> - 4:5.26.0-393
- Stop providing old perl(MODULE_COMPAT_5.24.*)
--
cgit v1.1
https://src.fedoraproject.org/cgit/perl.git/commit/?h=master&id=f7e5d464be66b2023d9ebcd06b963e0896cda78f
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