On Fri, Jan 18, 2019 at 10:37:25AM +0100, Marcel Holtmann wrote: > Hi Greg, > > > The L2CAP_CONF_EFS and L2CAP_CONF_RFC messages can be sent from > > userspace so their structure sizes need to be checked before parsing > > them. > > this message is confusing me. How can these be send from userspace?
So claimed the original reporter. You have the information in your inbox, is it incorrect? > > > > Based on a patch from Ran Menscher. > > > > Reported-by: Ran Menscher <ran.mensc...@karambasecurity.com> > > Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> > > --- > > net/bluetooth/l2cap_core.c | 12 ++++++++---- > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c > > index 93daf94565cf..55e48e6efc2b 100644 > > --- a/net/bluetooth/l2cap_core.c > > +++ b/net/bluetooth/l2cap_core.c > > @@ -3361,7 +3361,8 @@ static int l2cap_parse_conf_req(struct l2cap_chan > > *chan, void *data, size_t data > > break; > > > > case L2CAP_CONF_RFC: > > - if (olen == sizeof(rfc)) > > + if ((olen == sizeof(rfc)) && > > + (endptr - ptr >= L2CAP_CONF_OPT_SIZE + sizeof(rfc))) > > memcpy(&rfc, (void *) val, olen); > > We don’t do ((x == y) && (..)) actually. Using (x == y && ..) is plenty. Ick, ok, whatever, you all trust that your brains can remember C priority levels, me, I trust ()... I can fix this up to remove the extra (), but I would like _SOMEONE_ to at least validate that this resolves the reported issues... thanks, greg k-h
