Fix an use-after-free in substr() that modifies a magic variable

This commit is contained in:
Petr Písař 2017-03-08 11:58:24 +01:00
parent 2f5d87ed75
commit 32d6785b6d
2 changed files with 111 additions and 0 deletions

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@ -0,0 +1,104 @@
From 4fe0e2d067ac5639d94f35f8c7e8ac4e0e3ab336 Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Mon, 20 Feb 2017 11:02:21 +1100
Subject: [PATCH] (perl #129340) copy the source when inside the dest in
sv_insert_flags()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Ported to 5.24.1:
commit e7a8a8aac45d42d72d1586227ca51771f193f5dc
Author: Tony Cook <tony@develop-help.com>
Date: Mon Feb 20 11:02:21 2017 +1100
(perl #129340) copy the source when inside the dest in sv_insert_flags()
Signed-off-by: Petr Písař <ppisar@redhat.com>
---
embed.fnc | 2 +-
proto.h | 2 +-
sv.c | 12 +++++++++++-
t/op/substr.t | 5 ++++-
4 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/embed.fnc b/embed.fnc
index a64ffba..2395efb 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -1437,7 +1437,7 @@ Amdb |void |sv_insert |NN SV *const bigstr|const STRLEN offset \
|const STRLEN len|NN const char *const little \
|const STRLEN littlelen
Apd |void |sv_insert_flags|NN SV *const bigstr|const STRLEN offset|const STRLEN len \
- |NN const char *const little|const STRLEN littlelen|const U32 flags
+ |NN const char *little|const STRLEN littlelen|const U32 flags
Apd |int |sv_isa |NULLOK SV* sv|NN const char *const name
Apd |int |sv_isobject |NULLOK SV* sv
Apd |STRLEN |sv_len |NULLOK SV *const sv
diff --git a/proto.h b/proto.h
index fb4ee29..2b2004a 100644
--- a/proto.h
+++ b/proto.h
@@ -3015,7 +3015,7 @@ PERL_CALLCONV void Perl_sv_inc_nomg(pTHX_ SV *const sv);
/* PERL_CALLCONV void Perl_sv_insert(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *const little, const STRLEN littlelen); */
#define PERL_ARGS_ASSERT_SV_INSERT \
assert(bigstr); assert(little)
-PERL_CALLCONV void Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *const little, const STRLEN littlelen, const U32 flags);
+PERL_CALLCONV void Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *little, const STRLEN littlelen, const U32 flags);
#define PERL_ARGS_ASSERT_SV_INSERT_FLAGS \
assert(bigstr); assert(little)
PERL_CALLCONV int Perl_sv_isa(pTHX_ SV* sv, const char *const name);
diff --git a/sv.c b/sv.c
index d1e84f0..697db41 100644
--- a/sv.c
+++ b/sv.c
@@ -6223,7 +6223,7 @@ C<SvPV_force_flags> that applies to C<bigstr>.
*/
void
-Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *const little, const STRLEN littlelen, const U32 flags)
+Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *little, const STRLEN littlelen, const U32 flags)
{
char *big;
char *mid;
@@ -6236,6 +6236,16 @@ Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN l
SvPV_force_flags(bigstr, curlen, flags);
(void)SvPOK_only_UTF8(bigstr);
+
+ if (little >= SvPVX(bigstr) &&
+ little < SvPVX(bigstr) + (SvLEN(bigstr) ? SvLEN(bigstr) : SvCUR(bigstr))) {
+ /* little is a pointer to within bigstr, since we can reallocate bigstr,
+ or little...little+littlelen might overlap offset...offset+len we make a copy
+ */
+ little = savepvn(little, littlelen);
+ SAVEFREEPV(little);
+ }
+
if (offset + len > curlen) {
SvGROW(bigstr, offset+len+1);
Zero(SvPVX(bigstr)+curlen, offset+len-curlen, char);
diff --git a/t/op/substr.t b/t/op/substr.t
index eae2403..01c36a9 100644
--- a/t/op/substr.t
+++ b/t/op/substr.t
@@ -22,7 +22,7 @@ $SIG{__WARN__} = sub {
}
};
-plan(388);
+plan(389);
run_tests() unless caller;
@@ -869,3 +869,6 @@ is($destroyed, 1, 'Timely scalar destruction with lvalue substr');
is($result_3363, "best", "ref-to-substr retains lvalue-ness under recursion [perl #3363]");
}
+
+# failed with ASAN
+fresh_perl_is('$0 = "/usr/bin/perl"; substr($0, 0, 0, $0)', '', {}, "(perl #129340) substr() with source in target");
--
2.7.4

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@ -305,6 +305,10 @@ Patch86: perl-5.25.9-avoid-a-leak-in-list-assign-from-to-magic-values.pat
# in upstream after 5.25.9 # in upstream after 5.25.9
Patch87: perl-5.24.1-perl-130815-fix-ck_return-null-pointer-deref-on-malf.patch Patch87: perl-5.24.1-perl-130815-fix-ck_return-null-pointer-deref-on-malf.patch
# Fix an use-after-free in substr() that modifies a magic variable, RT#129340,
# in upstream after 5.25.9
Patch88: perl-5.24.1-perl-129340-copy-the-source-when-inside-the-dest-in-.patch
# Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048 # 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 Patch200: perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch
@ -3018,6 +3022,7 @@ popd
%patch85 -p1 %patch85 -p1
%patch86 -p1 %patch86 -p1
%patch87 -p1 %patch87 -p1
%patch88 -p1
%patch200 -p1 %patch200 -p1
%patch201 -p1 %patch201 -p1
@ -3090,6 +3095,7 @@ perl -x patchlevel.h \
'Fedora Patch85: Fix a heap buffer overflow when evaluating regexps with embedded code blocks from more than one source, RT#129881' \ 'Fedora Patch85: Fix a heap buffer overflow when evaluating regexps with embedded code blocks from more than one source, RT#129881' \
'Fedora Patch86: Fix a memory leak in list assignment from or to magic values, (RT#130766)' \ 'Fedora Patch86: Fix a memory leak in list assignment from or to magic values, (RT#130766)' \
'Fedora Patch87: Fix a null-pointer dereference on malformed code (RT#130815)' \ 'Fedora Patch87: Fix a null-pointer dereference on malformed code (RT#130815)' \
'Fedora Patch88: Fix an use-after-free in substr() that modifies a magic variable (RT#129340)' \
'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on Linux' \ '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' \ 'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \
%{nil} %{nil}
@ -5368,6 +5374,7 @@ popd
%changelog %changelog
* Wed Mar 08 2017 Petr Pisar <ppisar@redhat.com> - 4:5.24.1-390 * Wed Mar 08 2017 Petr Pisar <ppisar@redhat.com> - 4:5.24.1-390
- Fix a null-pointer dereference on malformed code (RT#130815) - Fix a null-pointer dereference on malformed code (RT#130815)
- Fix an use-after-free in substr() that modifies a magic variable (RT#129340)
* Fri Feb 17 2017 Petr Pisar <ppisar@redhat.com> - 4:5.24.1-389 * Fri Feb 17 2017 Petr Pisar <ppisar@redhat.com> - 4:5.24.1-389
- Adapt Compress::Raw::Zlib to zlib-1.2.11 (bug #1420326) - Adapt Compress::Raw::Zlib to zlib-1.2.11 (bug #1420326)