arjanv wrote:
> examle: pseudocode for the unlink syscall
>
> long your_wrapped_syscall(char *userfilename)
> {
> char kernelpointer[something];
> copy_from_user(kernelpointer, usefilename, ...);
> audit_log(kernelpointer);
> return original_syscall(userfilename);
> }
That code has another hole that nobody else has mentioned
yet: I can fill the audit log by trying to delete nonexistent files,
and if accused of trying to mount a DOS attack on the audit trail
I can reasonably claim that it was all an accident...
How about:
long wrapped_unlink(char *userfilename)
{
char name1[len], name2[len];
long ret;
copy_from_user(name1, userfilename, ...);
ret = original_unlink(userfilename);
copy_from_user(name2, userfilename, ...);
if (strncmp(name1, name2, len))
audit_log(name1, name2, UNLINK_NAME_CHANGED);
if (ret == 0 && AUDIT_SUCCESS)
audit_log(name1, name2, UNLINK_SUCCEEDED);
if (ret == -EPERM && AUDIT_FAILURE)
audit_log(name1, name2, UNLINK_FAILED);
return ret;
}
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This archive was generated by hypermail 2b29 : Thu May 15 2003 - 22:00:37 EST