> 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
