boostorg / boostorg/iterator

Past The End iterator dereference in filter_iterator

Aperta
#71 3 commenti 0 reazioni 0 assegnatari Vedi su GitHub
Lingua principale
C++
Stelle
23
Fork
70
Metriche di merge delle PR
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Descrizione

This simple test program segfaults on my GCC box with Boost 1.78

```c++
#include
#include
#include

int main() {
struct False { bool operator()(unsigned char) const { return false; } };

std::array const s{'A','B','C'};
using FIt = boost::iterators::filter_iterator;

for (FIt it(False{}, s.begin(), s.end()), end(s.end()); it != end; ++it) {
std::cout << static_cast(*it) << " ";
};
}
```

See it live with ASAN: https://godbolt.org/z/8c9f1drGn

```
=================================================================
==1==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffc00329dc3 at pc 0x0000004fc947 bp 0x7ffc00329d90 sp 0x7ffc00329d88
READ of size 1 at 0x7ffc00329dc3 thread T0
#0 0x4fc946 in main /app/example.cpp:12:39
#1 0x7f90b8b920b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x240b2)
#2 0x41f34d in _start (/app/output.s+0x41f34d)

Address 0x7ffc00329dc3 is located in stack of thread T0 at offset 35 in frame
#0 0x4fc853 in main /app/example.cpp:5

This frame has 1 object(s):
[32, 35) 's' (line 8) <== Memory access at offset 35 overflows this variable
HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork
(longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow /app/example.cpp:12:39 in main
Shadow bytes around the buggy address:
0x10000005d360: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x10000005d370: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x10000005d380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x10000005d390: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x10000005d3a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x10000005d3b0: 00 00 00 00 f1 f1 f1 f1[03]f3 f3 f3 00 00 00 00
0x10000005d3c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x10000005d3d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x10000005d3e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x10000005d3f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x10000005d400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==1==ABORTING
```

Guida per i contributori

Nessuna guida per i contributori indicizzata per questo repository

Direzione di ricerca

Riproduci l’esempio dell’issue con GCC e ASAN, quindi esamina boost/iterator/filter_iterator.hpp per seguire la gestione dell’iteratore di fine. Il lavoro è completato quando il predicato sempre falso non dereferenzia più oltre l’intervallo e l’esempio termina senza un errore di ASAN.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Valutazione

Stack tecnologico
cpp
Ambito
tooling
Tipo di issue
Bug
Difficoltà
3/5
Tempo stimato
1-2 giorni
Stato di attività
Ferma
Chiarezza
Abbastanza chiara
Idoneità per principianti
45/100

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