On Mon, Oct 10, 2022 at 8:54 AM David Laight <David.Laight@xxxxxxxxxx> wrote: > From: Alexei Starovoitov > > Sent: 07 October 2022 22:55 > .... > > Not easy at all. > > There is only way place in the whole kernel that does: > > return sk_getsockopt(sk, SOL_SOCKET, optname, > > KERNEL_SOCKPTR(optval), > > KERNEL_SOCKPTR(optlen)); > > Until I add change my out of tree driver to work with > the new code. > (Although it actually needs to do a getsockopt into SCTP.) > > I didn't spot the change to sk_getsockopt() going though. > But KERNEL_SOCKPTR() is really the wrong function/type > for the length. > It would be much safer to have a struct with two members, > one an __user pointer and one a kernel pointer both to > socklen_t. Yes, agreed. > It isn't really ideal for the buffer pointer either. > That started as a single field (assuming the caller > has verified the user/kernel status), then the is_kernel > field was added for architectures where user/kernel > addresses use the same values. > Then a horrid bug (forgotten where) forced the is_kernel > field be used everywhere. > Again a structure with two pointers would be much safer. Any chance you have plans to work on this David? -- paul-moore.com
