Where to put the star in C and C++ pointer notation

No. Never. <g>

But consider:

int* var1, var2;

Here, the placement of the * is misleading, because it does not apply to var2, which is an int and not an int*.

The Linux kernel coding style convention is:

int *ptr1 , *ptr2;

So I think you should adopt it as your convention.

When declaring pointer data or a function that returns a pointer type, the preferred use of * is adjacent to the data name or function name and not adjacent to the type name. Examples:

char *linux_banner;
unsigned long long memparse(char *ptr, char **retptr);
char *match_strdup(substring_t *s);

I believe part of the reason for this notation is so that the usage and declaration of a variable look similar.

int *var;
int x;
x = *var;

You can also think of it as saying that dereferencing var will give you an int.