github / github/codeql

False positives in cpp/use-after-free

Aperta
#15,676 1 commento 0 reazioni 0 assegnatari Vedi su GitHub
C++ false-positive
Lingua principale
CodeQL
Stelle
10.1k
Fork
2.1k
Merge medio
2g 15h
PR unite (30g)
141

Descrizione

I'm getting about 20 of these on my code but I'll only show one because they're all the same.

CodeQL is identifying this as a potential use after free because there's a `delete[]` on line 3 of this sample. But line 5 calls `new[]` so the pointer used on line 6 should never be dangerous to use. I don't know if CodeQL is confused by the number of pointers but this isn't an issue.

Step 1 pointer to operator delete[] output argument
Step 2 *m_CSEngine [post update] [m_arrSpeedInit]
Step 3 *m_pRaw [post update] [*m_CSEngine, m_arrSpeedInit]
Step 4 *this [post update] [*m_pRaw, *m_CSEngine, m_arrSpeedInit]
Step 5 *this [*m_pRaw, *m_CSEngine, m_arrSpeedInit]
Step 6 *m_pRaw [*m_CSEngine, m_arrSpeedInit]
Step 7 *m_CSEngine [m_arrSpeedInit]
Step 8 m_arrSpeedInit - Memory may have been previously freed by delete[].

```
if (((CRawDetectionPlate*)m_pRaw)->m_CSEngine->m_arrSpeedInit!=NULL)
{
delete []((CRawDetectionPlate*)m_pRaw)->m_CSEngine->m_arrSpeedInit; // <- Steps 1, 2, 3, 4
}
((CRawDetectionPlate*)m_pRaw)->m_CSEngine->m_arrSpeedInit = new int[((CRawDetectionPlate*)m_pRaw)->m_CSEngine->m_numberObj];
memcpy(((CRawDetectionPlate*)m_pRaw)->m_CSEngine->m_arrSpeedInit,(BYTE*)p+pos,((CRawDetectionPlate*)m_pRaw)->m_CSEngine->m_numberObj*sizeof(int)); // <- Steps 5, 6, 7, 8
```

Guida per i contributori

Apri la guida per i contributori

Valutazione

Questa issue non è ancora stata valutata.

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.