[gcc r11-5653] libstdc++: Fix null pointer dereferences in __gnu_cxx::rope
Jonathan Wakely
redi@gcc.gnu.org
Wed Dec 2 12:29:44 GMT 2020
https://gcc.gnu.org/g:74270a546cf75aad5e2db642b4715728d4da7904
commit r11-5653-g74270a546cf75aad5e2db642b4715728d4da7904
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed Dec 2 12:29:00 2020 +0000
libstdc++: Fix null pointer dereferences in __gnu_cxx::rope
This fixes UBsan errors like:
/usr/include/c++/10/ext/ropeimpl.h:593:9: runtime error: member access within null pointer of type 'struct _RopeRep'
/usr/include/c++/10/ext/ropeimpl.h:593:9: runtime error: member call on null pointer of type 'struct _Rope_rep_base'
/usr/include/c++/10/ext/rope:556:17: runtime error: reference binding to null pointer of type 'struct allocator_type'
/usr/include/c++/10/ext/ropeimpl.h:593:9: runtime error: reference binding to null pointer of type 'struct allocator_type'
/usr/include/c++/10/ext/rope:1700:30: runtime error: member call on null pointer of type 'struct new_allocator'
/usr/include/c++/10/ext/new_allocator.h:105:29: runtime error: member call on null pointer of type 'struct new_allocator'
/usr/include/c++/10/ext/rope:1702:26: runtime error: reference binding to null pointer of type 'const struct allocator'
/usr/include/c++/10/bits/allocator.h:148:34: runtime error: reference binding to null pointer of type 'const struct new_allocator'
/usr/include/c++/10/ext/rope:1664:39: runtime error: reference binding to null pointer of type 'const struct allocator'
/usr/include/c++/10/ext/rope:1665:9: runtime error: reference binding to null pointer of type 'const struct allocator_type'
/usr/include/c++/10/ext/rope:725:36: runtime error: reference binding to null pointer of type 'const struct allocator_type'
/usr/include/c++/10/ext/rope:614:64: runtime error: reference binding to null pointer of type 'const struct allocator_type'
The problem is calling r->_M_get_allocator() when r is null.
libstdc++-v3/ChangeLog:
* include/ext/rope (rope::_S_concat_char_iter)
(rope::_S_destr_concat_char_iter): Add allocator parameter.
(rope::push_back, rope::append, rope::insert, operator+):
Pass allocator.
* include/ext/ropeimpl.h (rope::_S_concat_char_iter)
(rope::_S_destr_concat_char_iter): Add allocator parameter
and use it.
(_Rope_char_ref_proxy::operator=(_CharT)): Pass allocator.
Diff:
---
libstdc++-v3/include/ext/rope | 31 ++++++++++++++++++++-----------
libstdc++-v3/include/ext/ropeimpl.h | 23 +++++++++++------------
2 files changed, 31 insertions(+), 23 deletions(-)
diff --git a/libstdc++-v3/include/ext/rope b/libstdc++-v3/include/ext/rope
index 8479acd8f74..de6ecdd524f 100644
--- a/libstdc++-v3/include/ext/rope
+++ b/libstdc++-v3/include/ext/rope
@@ -1612,19 +1612,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static _RopeRep* _S_concat_char_iter(_RopeRep* __r,
const _CharT* __iter,
- size_type __slen);
- // Concatenate rope and char ptr, copying __s.
+ size_type __slen,
+ allocator_type& __a);
+ // Concatenate rope and char ptr, copying __iter.
// Should really take an arbitrary iterator.
// Result is counted in refcount.
static _RopeRep* _S_destr_concat_char_iter(_RopeRep* __r,
const _CharT* __iter,
- size_type __slen)
+ size_type __slen,
+ allocator_type& __a)
// As above, but one reference to __r is about to be
// destroyed. Thus the pieces may be recycled if all
// relevant reference counts are 1.
#ifdef __GC
// We can't really do anything since refcounts are unavailable.
- { return _S_concat_char_iter(__r, __iter, __slen); }
+ { return _S_concat_char_iter(__r, __iter, __slen, __a); }
#else
;
#endif
@@ -1913,9 +1915,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void
push_back(_CharT __x)
{
+ allocator_type __a = _M_get_allocator();
_RopeRep* __old = this->_M_tree_ptr;
this->_M_tree_ptr
- = _S_destr_concat_char_iter(this->_M_tree_ptr, &__x, 1);
+ = _S_destr_concat_char_iter(this->_M_tree_ptr, &__x, 1, __a);
_S_unref(__old);
}
@@ -2115,8 +2118,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
rope&
append(const _CharT* __iter, size_type __n)
{
+ allocator_type __a = _M_get_allocator();
_RopeRep* __result =
- _S_destr_concat_char_iter(this->_M_tree_ptr, __iter, __n);
+ _S_destr_concat_char_iter(this->_M_tree_ptr, __iter, __n, __a);
_S_unref(this->_M_tree_ptr);
this->_M_tree_ptr = __result;
return *this;
@@ -2133,8 +2137,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
rope&
append(const _CharT* __s, const _CharT* __e)
{
+ allocator_type __a = _M_get_allocator();
_RopeRep* __result =
- _S_destr_concat_char_iter(this->_M_tree_ptr, __s, __e - __s);
+ _S_destr_concat_char_iter(this->_M_tree_ptr, __s, __e - __s, __a);
_S_unref(this->_M_tree_ptr);
this->_M_tree_ptr = __result;
return *this;
@@ -2156,8 +2161,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
rope&
append(_CharT __c)
{
+ allocator_type __a = _M_get_allocator();
_RopeRep* __result =
- _S_destr_concat_char_iter(this->_M_tree_ptr, &__c, 1);
+ _S_destr_concat_char_iter(this->_M_tree_ptr, &__c, 1, __a);
_S_unref(this->_M_tree_ptr);
this->_M_tree_ptr = __result;
return *this;
@@ -2239,7 +2245,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Self_destruct_ptr __left(_S_substring(this->_M_tree_ptr, 0, __p));
_Self_destruct_ptr __right(_S_substring(this->_M_tree_ptr,
__p, size()));
- _Self_destruct_ptr __left_result(_S_concat_char_iter(__left, __i, __n));
+ _Self_destruct_ptr __left_result(_S_concat_char_iter(__left, __i, __n,
+ _M_get_allocator()));
// _S_ destr_concat_char_iter should be safe here.
// But as it stands it's probably not a win, since __left
// is likely to have additional references.
@@ -2843,8 +2850,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
typedef rope<_CharT, _Alloc> rope_type;
std::size_t __rlen = rope_type::_S_char_ptr_len(__right);
+ _Alloc __a = __left.get_allocator();
return rope_type(rope_type::_S_concat_char_iter(__left._M_tree_ptr,
- __right, __rlen));
+ __right, __rlen, __a));
}
template <class _CharT, class _Alloc>
@@ -2861,8 +2869,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator+(const rope<_CharT, _Alloc>& __left, _CharT __right)
{
typedef rope<_CharT, _Alloc> rope_type;
+ _Alloc __a = __left.get_allocator();
return rope_type(rope_type::_S_concat_char_iter(__left._M_tree_ptr,
- &__right, 1));
+ &__right, 1, __a));
}
template <class _CharT, class _Alloc>
diff --git a/libstdc++-v3/include/ext/ropeimpl.h b/libstdc++-v3/include/ext/ropeimpl.h
index c5d3a0c1aef..e571847d2c5 100644
--- a/libstdc++-v3/include/ext/ropeimpl.h
+++ b/libstdc++-v3/include/ext/ropeimpl.h
@@ -524,7 +524,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template <class _CharT, class _Alloc>
typename rope<_CharT, _Alloc>::_RopeRep*
rope<_CharT, _Alloc>::
- _S_concat_char_iter(_RopeRep* __r, const _CharT*__s, std::size_t __slen)
+ _S_concat_char_iter(_RopeRep* __r, const _CharT*__s, std::size_t __slen,
+ allocator_type& __a)
{
using std::size_t;
_RopeRep* __result;
@@ -534,8 +535,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __r;
}
if (0 == __r)
- return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,
- __r->_M_get_allocator());
+ return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __a);
if (__r->_M_tag == __detail::_S_leaf
&& __r->_M_size + __slen <= size_t(_S_copy_max))
{
@@ -564,8 +564,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __result;
}
}
- _RopeRep* __nright =
- __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->_M_get_allocator());
+ _RopeRep* __nright = __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __a);
__try
{
__r->_M_ref_nonnil();
@@ -585,17 +584,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
typename rope<_CharT,_Alloc>::_RopeRep*
rope<_CharT,_Alloc>::
_S_destr_concat_char_iter(_RopeRep* __r, const _CharT* __s,
- std::size_t __slen)
+ std::size_t __slen, allocator_type& __a)
{
using std::size_t;
_RopeRep* __result;
if (0 == __r)
- return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,
- __r->_M_get_allocator());
+ return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __a);
size_t __count = __r->_M_ref_count;
size_t __orig_size = __r->_M_size;
if (__count > 1)
- return _S_concat_char_iter(__r, __s, __slen);
+ return _S_concat_char_iter(__r, __s, __slen, __a);
if (0 == __slen)
{
__r->_M_ref_count = 2; // One more than before
@@ -632,8 +630,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __r;
}
}
- _RopeRep* __right =
- __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->_M_get_allocator());
+ _RopeRep* __right = __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __a);
__r->_M_ref_nonnil();
__try
{ __result = _S_tree_concat(__r, __right); }
@@ -1500,9 +1497,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Self_destruct_ptr __left(_My_rope::_S_substring(__old, 0, _M_pos));
_Self_destruct_ptr __right(_My_rope::_S_substring(__old, _M_pos + 1,
__old->_M_size));
+ typename _RopeRep::allocator_type __a = _M_root->_M_get_allocator();
_Self_destruct_ptr __result_left(_My_rope::
_S_destr_concat_char_iter(__left,
- &__c, 1));
+ &__c, 1,
+ __a));
_RopeRep* __result = _My_rope::_S_concat(__result_left, __right);
#ifndef __GC
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