On Wed, Sep 16, 2020 at 10:34 AM Greg Rose <[email protected]> wrote: > > From: Guillaume Nault <[email protected]> > > Upstream commit: > commit d4e4fdf9e4a27c87edb79b1478955075be141f67 > Author: Guillaume Nault <[email protected]> > Date: Wed Oct 23 18:39:04 2019 +0200 > > netns: fix GFP flags in rtnl_net_notifyid() > > In rtnl_net_notifyid(), we certainly can't pass a null GFP flag to > rtnl_notify(). A GFP_KERNEL flag would be fine in most circumstances, > but there are a few paths calling rtnl_net_notifyid() from atomic > context or from RCU critical sections. The later also precludes the use > of gfp_any() as it wouldn't detect the RCU case. Also, the nlmsg_new() > call is wrong too, as it uses GFP_KERNEL unconditionally. > > Therefore, we need to pass the GFP flags as parameter and propagate it > through function calls until the proper flags can be determined. > > In most cases, GFP_KERNEL is fine. The exceptions are: > * openvswitch: ovs_vport_cmd_get() and ovs_vport_cmd_dump() > indirectly call rtnl_net_notifyid() from RCU critical section, > > * rtnetlink: rtmsg_ifinfo_build_skb() already receives GFP flags as > parameter. > > Also, in ovs_vport_cmd_build_info(), let's change the GFP flags used > by nlmsg_new(). The function is allowed to sleep, so better make the > flags consistent with the ones used in the following > ovs_vport_cmd_fill_info() call. > > Found by code inspection. > > Fixes: 9a9634545c70 ("netns: notify netns id events") > Signed-off-by: Guillaume Nault <[email protected]> > Acked-by: Nicolas Dichtel <[email protected]> > Acked-by: Pravin B Shelar <[email protected]> > Signed-off-by: David S. Miller <[email protected]> > > Backport the datapath.c portion of this fix. > > Cc: Guillaume Nault <[email protected]> > Signed-off-by: Greg Rose <[email protected]> > ---
LGTM. Acked-by: Yi-Hung Wei <[email protected]> _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
