On Sun, Oct 18, 2026 at 10:34:12AM -1000, Linus Torvalds wrote: > On Sun, 18 Oct 2026 at 09:26, Michael S. Tsirkin <[email protected]> wrote: > > > > + __virtio16 __user *uaddr = ivec.iov.iovec[0].iov_base; > > + > > + if (!access_ok(uaddr, sizeof(*p))) > > + return -EFAULT; > > + ret = __get_user(tmp, uaddr); > > You should never use __get_user() in the first place. It is almost > always just a bug.
Right, I was thinking of some other code. This one should just be get_user. > And __get_user() together with access_ok() is actively wrong and > stupid. It's slower, bigger, and more bug-prone than just using > "get_user()". > > The *only* reason ever to use __get_user() is in very very iffy code > that might use a kernel pointer and doesn't want the access_ok() code. > > Or old legacy code from the last century when __get_user() was faster > and was inlined. > > Linus
