Robert O'Callahan reported that since struct iwreq is smaller than struct ifreq, if it happens to land at the end of a mapped section userspace will erroneously get -EFAULT.
Bug report is https://bugzilla.kernel.org/show_bug.cgi?id=195869. This bug is ancient, it kernel 2.1.15 was the first to contain the bug, and was released almost exactly 20.5 years ago. Dave, I don't know if we should even bother sending this to stable, but if so, the third patch will apply by itself but not compile, a smaller patch consist of only the net/core/dev_ioctl.c modifications with a cast thrown in where the compile fails/warns due to passing the wrong struct type. Should I merge this through my tree? johannes
