a case of CWE: 788

[AlexHsieh]

Hi,
I use cppcheck-2.14.1 to check the following code

#pragma pack(1)
typedef struct
{
   long  a1;
   char  a2;
} SA;  
#pragma pack()

void f()
{
    SA a;
    char b[5] = {};
    memmove(&a, b, sizeof(a));
}

, and get
CWE: 788
Buffer is accessed out of bounds: b

Is this a false positive?

[Andrew C Aitchison]

long is 8 bytes on most 64bit systems. 8+1 > 5 ... but I still get the warning with
char b[15] = {};

But

void f()
{
SA a[2];
char b[31] = {};
memmove(&a, b, sizeof(a));
}
also fails, suggesting that the long in a[1] will be aligned to b[16].
So, I think cppcheck is ignoring #pragma pack(1)

[AlexHsieh]

thank you for sharing

[CHR]

Related ticket: https://trac.cppcheck.net/ticket/12060