Date: Tue, 25 Feb 2020 06:13:12 +0000 From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 244247] Kernel panic due to racecondition in ng_eiface shutdown Message-ID: <bug-244247-7501-BJWa5Ja4Es@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-244247-7501@https.bugs.freebsd.org/bugzilla/> References: <bug-244247-7501@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D244247 Aleksandr Fedorov <aleksandr.fedorov@itglobal.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |aleksandr.fedorov@itglobal. | |com --- Comment #10 from Aleksandr Fedorov <aleksandr.fedorov@itglobal.com> --- It seems that there are a race in the function ng_eiface_rmnode(). 613 static int 614 ng_eiface_rmnode(node_p node) 615 { 616 const priv_p priv =3D NG_NODE_PRIVATE(node); 617 struct ifnet *const ifp =3D priv->ifp; 618=20=20=20=20=20 619 /* 620 * the ifnet may be in a different vnet than the netgraph n= ode,=20 621 * hence we have to change the current vnet context here. 622 */ 623 CURVNET_SET_QUIET(ifp->if_vnet); 624 ifmedia_removeall(&priv->media); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Remove media 625 ether_ifdetach(ifp); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Detach interface. Remove interface from ifnet's list which protected by WLOCK(). 626 if_free(ifp); 627 CURVNET_RESTORE(); 628 free_unr(V_ng_eiface_unit, priv->unit); 629 free(priv, M_NETGRAPH); 630 NG_NODE_SET_PRIVATE(node, NULL); 631 NG_NODE_UNREF(node); 632 return (0); 633 } So, the media is already removed, but the interface is still available. I think the order should be different, like other interfaces do: 1) Detach interface. 2) Free used resources. Can you test the next patch: Index: sys/netgraph/ng_eiface.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- sys/netgraph/ng_eiface.c (revision 358308) +++ sys/netgraph/ng_eiface.c (working copy) @@ -621,9 +621,9 @@ * hence we have to change the current vnet context here. */ CURVNET_SET_QUIET(ifp->if_vnet); - ifmedia_removeall(&priv->media); ether_ifdetach(ifp); if_free(ifp); + ifmedia_removeall(&priv->media); CURVNET_RESTORE(); free_unr(V_ng_eiface_unit, priv->unit); free(priv, M_NETGRAPH); --=20 You are receiving this mail because: You are the assignee for the bug.=
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