> -----原始邮件----- > 发件人: "Saleem, Shiraz" <shiraz.saleem@xxxxxxxxx> > 发送时间: 2021-03-12 09:13:39 (星期五) > 收件人: "Jason Gunthorpe" <jgg@xxxxxxxxxx>, "Lv Yunlong" <lyl2019@xxxxxxxxxxxxxxxx> > 抄送: "Latif, Faisal" <faisal.latif@xxxxxxxxx>, "dledford@xxxxxxxxxx" <dledford@xxxxxxxxxx>, "linux-rdma@xxxxxxxxxxxxxxx" <linux-rdma@xxxxxxxxxxxxxxx>, "linux-kernel@xxxxxxxxxxxxxxx" <linux-kernel@xxxxxxxxxxxxxxx> > 主题: RE: [PATCH] infiniband/i40iw: Fix a use after free in i40iw_cm_event_handler > > > Subject: Re: [PATCH] infiniband/i40iw: Fix a use after free in > > i40iw_cm_event_handler > > > > On Wed, Mar 10, 2021 at 07:14:14PM -0800, Lv Yunlong wrote: > > > In the case of I40IW_CM_EVENT_ABORTED, i40iw_event_connect_error() > > > could be called to free the event->cm_node. However, event->cm_node > > > will be used after and cause use after free. It needs to add flags to > > > inform that event->cm_node has been freed. > > > > > > Signed-off-by: Lv Yunlong <lyl2019@xxxxxxxxxxxxxxxx> > > > --- > > > drivers/infiniband/hw/i40iw/i40iw_cm.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > This might be OK (though I don't like the free variable), Shiraz?? > > > > How was this reproduced? Do you have some call trace leading up to use after free? > > The cm_node refcnt is bumped at creation time and once in i40iw_receive_ilq before packet is processed. > That should protect the cm_node from disappearing in the event handler in the abort event case. > The dec at end of i40iw_receive ilq should be point where the cm_node is freed specifically in the abort case. > > Shiraz > This problem was reported by a path-sensitive analyzer developed by our Security Lab(Loccs). The analyzer reported that there is a feasible path to free event->cm_node and use it after, and that is what i described in the first commit. Thanks.
