On Fri, May 21, 2021 at 03:17:46PM +0200, Johan Hovold wrote: > On Fri, May 21, 2021 at 10:03:26AM +0200, Johan Hovold wrote: > > So first, this should probably be rate limited. > > This could actually be done using WARN_ON_ONCE() as we don't have to > worry about syzbot fuzzing descriptors here (all control endpoints are > bidirectional). > > > Second, did you try to estimate how many call sites that get this wrong? > > I always felt a bit pedantic when pointing out that the pipe direction > > should match the request type to driver author's during review when (in > > almost all cases?) this hasn't really mattered. I fear we may have > > accumulated a fairly large number of these mismatches over the years but > > I haven't verified that. > > I did a quick review of all ctrlpipe-macro uses in usb/misc and > usb/serial and found two instances. > > A simple grep pattern looking for explicit USB_DIR/ctrlpipe mismatches > caught another five tree wide (not including the > sound/usb/mixer_scarlett_gen2.c which Geoffrey reported), but there are > likely more of those out there as the request type is often not that > explicit. > > I've prepared patches for the above, excluding the sound driver Geoffrey > said he was fixing. Many thanks for making the effort to do this. Alan Stern
