https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103233
Bug ID: 103233
Summary: Warning from system libraries in user code: CWE-476
-Werror=analyzer-null-dereference
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: colomar.6.4.3 at gmail dot com
Target Milestone: ---
There are two problems here:
One is a dereference of a NULL pointer in the standard C++ library code
(at least that's what -fanalyzer reports).
Another is that I'm seeing the error while compiling user code (my library):
<https://github.com/alejandro-colomar/libalx>
c++ -D _GNU_SOURCE -D _POSIX_C_SOURCE=200809L -D
SYSCONFDIR_='"/usr/local/etc/alx"' -O3 -Wall -Wextra -Winvalid-pch -fno-common
-Werror -fpic -isystem/usr/local/include -D_GNU_SOURCE
-D_POSIX_C_SOURCE=200809L -isystem/usr/include/opencv4
-isystem/usr/local/include -D_GNU_SOURCE -D_POSIX_C_SOURCE=200809L
-isystem/usr/local/include -D_GNU_SOURCE -D_POSIX_C_SOURCE=200809L -fanalyzer
-std=gnu++20 -Wno-vla -I /home/alx/src/alx/libalx/include -fpreprocessed -S
-o /home/alx/src/alx/libalx/tmp/alx/cv/features2d/orb.cxx.s
/home/alx/src/alx/libalx/tmp/alx/cv/features2d/orb.cxx.i
In member function 'void std::vector<_Tp,
_Alloc>::_M_realloc_insert(std::vector<_Tp, _Alloc>::iterator, _Args&& ...)
[with _Args = {const cv::Point_<float>&}; _Tp = cv::Point_<float>; _Alloc =
std::allocator<cv::Point_<float> >]':
cc1plus: error: dereference of NULL '__cur' [CWE-476]
[-Werror=analyzer-null-dereference]
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': events 1-2
|
|/usr/include/c++/11/bits/vector.tcc:426:7:
| 426 | vector<_Tp, _Alloc>::
| | ^~~~~~~~~~~~~~~~~~~
| | |
| | (1) entry to 'std::vector<cv::Point_<float>
>::_M_realloc_insert<const cv::Point_<float>&>'
|......
| 436 | _M_check_len(size_type(1), "vector::_M_realloc_insert");
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (2) calling 'std::vector<cv::Point_<float>
>::_M_check_len' from 'std::vector<cv::Point_<float> >::_M_realloc_insert<const
cv::Point_<float>&>'
|
+--> 'std::vector<_Tp, _Alloc>::size_type std::vector<_Tp,
_Alloc>::_M_check_len(std::vector<_Tp, _Alloc>::size_type, const char*) const
[with _Tp = cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]':
events 3-5
|
|/usr/include/c++/11/bits/stl_vector.h:1756:7:
| 1756 | _M_check_len(size_type __n, const char* __s) const
| | ^~~~~~~~~~~~
| | |
| | (3) entry to 'std::vector<cv::Point_<float>
>::_M_check_len'
| 1757 | {
| 1758 | if (max_size() - size() < __n)
| | ~~
| | |
| | (4) following 'false' branch...
|......
| 1761 | const size_type __len = size() + (std::max)(size(),
__n);
| | ~~~~~~
| | |
| | (5)
...to here
|
<------+
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 6
|
|/usr/include/c++/11/bits/vector.tcc:436:21:
| 436 | _M_check_len(size_type(1), "vector::_M_realloc_insert");
| | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (6) returning to
'std::vector<cv::Point_<float> >::_M_realloc_insert<const cv::Point_<float>&>'
from 'std::vector<cv::Point_<float> >::_M_check_len'
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 7
|
|/usr/include/c++/11/bits/stl_vector.h:346:25:
| 346 | return __n != 0 ? _Tr::allocate(_M_impl, __n) : pointer();
| | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (7) following 'false' branch...
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 8
|
|/usr/include/c++/11/bits/vector.tcc:450:48:
| 450 | __new_start + __elems_before,
| | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~
| | |
| | (8) ...to here
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 9
|
|/usr/include/c++/11/bits/stl_uninitialized.h:1031:22:
| 1031 | for (; __first != __last; ++__first, (void)++__cur)
| | ~~~~~~~~^~~~~~~~~
| | |
| | (9) following 'true' branch (when '__first !=
<unknown>')...
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 10
|
|/usr/include/c++/11/bits/stl_construct.h:88:9:
| 88 | __location->~_Tp();
| | ^~~~~~~~~~
| | |
| | (10) ...to here
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 11
|
|cc1plus:
| (11): dereference of NULL '__cur'
|
cc1plus: error: dereference of possibly-NULL '__cur' [CWE-690]
[-Werror=analyzer-possible-null-dereference]
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': events 1-2
|
|/usr/include/c++/11/bits/vector.tcc:426:7:
| 426 | vector<_Tp, _Alloc>::
| | ^~~~~~~~~~~~~~~~~~~
| | |
| | (1) entry to 'std::vector<cv::Point_<float>
>::_M_realloc_insert<const cv::Point_<float>&>'
|......
| 436 | _M_check_len(size_type(1), "vector::_M_realloc_insert");
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (2) calling 'std::vector<cv::Point_<float>
>::_M_check_len' from 'std::vector<cv::Point_<float> >::_M_realloc_insert<const
cv::Point_<float>&>'
|
+--> 'std::vector<_Tp, _Alloc>::size_type std::vector<_Tp,
_Alloc>::_M_check_len(std::vector<_Tp, _Alloc>::size_type, const char*) const
[with _Tp = cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]':
events 3-5
|
|/usr/include/c++/11/bits/stl_vector.h:1756:7:
| 1756 | _M_check_len(size_type __n, const char* __s) const
| | ^~~~~~~~~~~~
| | |
| | (3) entry to 'std::vector<cv::Point_<float>
>::_M_check_len'
| 1757 | {
| 1758 | if (max_size() - size() < __n)
| | ~~
| | |
| | (4) following 'false' branch...
|......
| 1761 | const size_type __len = size() + (std::max)(size(),
__n);
| | ~~~~~~
| | |
| | (5)
...to here
|
<------+
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 6
|
|/usr/include/c++/11/bits/vector.tcc:436:21:
| 436 | _M_check_len(size_type(1), "vector::_M_realloc_insert");
| | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (6) returning to
'std::vector<cv::Point_<float> >::_M_realloc_insert<const cv::Point_<float>&>'
from 'std::vector<cv::Point_<float> >::_M_check_len'
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': events 7-8
|
|/usr/include/c++/11/bits/stl_vector.h:346:25:
| 346 | return __n != 0 ? _Tr::allocate(_M_impl, __n) : pointer();
| | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | | |
| | | (8) ...to here
| | (7) following 'true' branch...
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 9
|
|/usr/include/c++/11/bits/allocator.h:201:47:
| 201 | return __allocator_base<_Tp>::allocate(__n, 0);
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
| | |
| | (9) calling
'__gnu_cxx::new_allocator<cv::Point_<float> >::allocate' from
'std::vector<cv::Point_<float> >::_M_realloc_insert<const cv::Point_<float>&>'
|
+--> '_Tp*
__gnu_cxx::new_allocator<_Tp>::allocate(__gnu_cxx::new_allocator<_Tp>::size_type,
const void*) [with _Tp = cv::Point_<float>]': events 10-13
|
|/usr/include/c++/11/ext/new_allocator.h:103:7:
| 103 | allocate(size_type __n, const void* =
static_cast<const void*>(0))
| | ^~~~~~~~
| | |
| | (10) entry to
'__gnu_cxx::new_allocator<cv::Point_<float> >::allocate'
|......
| 111 | if (__builtin_expect(__n > this->_M_max_size(),
false))
| | ~~
| | |
| | (11) following 'false' branch...
|......
| 127 | return static_cast<_Tp*>(::operator new(__n *
sizeof(_Tp)));
| |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (12) ...to
here
| | (13) this
call could return NULL
|
<------+
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 14
|
|/usr/include/c++/11/bits/allocator.h:201:47:
| 201 | return __allocator_base<_Tp>::allocate(__n, 0);
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
| | |
| | (14) returning to
'std::vector<cv::Point_<float> >::_M_realloc_insert<const cv::Point_<float>&>'
from '__gnu_cxx::new_allocator<cv::Point_<float> >::allocate'
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 15
|
|/usr/include/c++/11/bits/stl_uninitialized.h:1031:22:
| 1031 | for (; __first != __last; ++__first, (void)++__cur)
| | ~~~~~~~~^~~~~~~~~
| | |
| | (15) following 'true' branch (when '__first
!= <unknown>')...
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 16
|
|/usr/include/c++/11/bits/stl_construct.h:88:9:
| 88 | __location->~_Tp();
| | ^~~~~~~~~~
| | |
| | (16) ...to here
|
'void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp,
_Alloc>::iterator, _Args&& ...) [with _Args = {const cv::Point_<float>&}; _Tp =
cv::Point_<float>; _Alloc = std::allocator<cv::Point_<float> >]': event 17
|
|cc1plus:
| (17): '__cur' could be NULL: unchecked value from (13)
|
cc1plus: all warnings being treated as errors
