Date: Tue, 9 Aug 2016 00:53:47 +0200 From: Oliver Pinter <oliver.pinter@hardenedbsd.org> To: Mark Johnston <markj@freebsd.org> Cc: "src-committers@freebsd.org" <src-committers@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org> Subject: Re: svn commit: r303855 - in head/sys: kern sys Message-ID: <CAPQ4ffsmwTAL%2Bv9RgY8e_%2Bn5CZKKL9ejNntuSNM71MQma5_o2w@mail.gmail.com> In-Reply-To: <201608082025.u78KP4aE048791@repo.freebsd.org> References: <201608082025.u78KP4aE048791@repo.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi! Can you please MFC back this change 10-STABLE together with the following: https://github.com/HardenedBSD/hardenedBSD/commit/576619e564618bca3675db57580d8e1f76bd2ac7 This issue is still exists on 10-STABLE, as you can test with the linked program from phabricator: https://people.freebsd.org/~mjg/reproducers/unp-gc-panic.c On Mon, Aug 8, 2016 at 10:25 PM, Mark Johnston <markj@freebsd.org> wrote: > Author: markj > Date: Mon Aug 8 20:25:04 2016 > New Revision: 303855 > URL: https://svnweb.freebsd.org/changeset/base/303855 > > Log: > Handle races with listening socket close when connecting a unix socket. > > If the listening socket is closed while sonewconn() is executing, the > nascent child socket is aborted, which results in recursion on the > unp_link lock when the child's pru_detach method is invoked. Fix this > by using a flag to mark such sockets, and skip a part of the socket's > teardown during detach. > > Reported by: Raviprakash Darbha <rdarbha@juniper.net> > Tested by: pho > MFC after: 2 weeks > Differential Revision: https://reviews.freebsd.org/D7398 > > Modified: > head/sys/kern/uipc_usrreq.c > head/sys/sys/unpcb.h > > Modified: head/sys/kern/uipc_usrreq.c > ============================================================================== > --- head/sys/kern/uipc_usrreq.c Mon Aug 8 20:23:11 2016 (r303854) > +++ head/sys/kern/uipc_usrreq.c Mon Aug 8 20:25:04 2016 (r303855) > @@ -430,6 +430,8 @@ uipc_attach(struct socket *so, int proto > unp->unp_socket = so; > so->so_pcb = unp; > unp->unp_refcount = 1; > + if (so->so_head != NULL) > + unp->unp_flags |= UNP_NASCENT; > > UNP_LIST_LOCK(); > unp->unp_gencnt = ++unp_gencnt; > @@ -652,14 +654,22 @@ uipc_detach(struct socket *so) > unp = sotounpcb(so); > KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); > > - UNP_LINK_WLOCK(); > + vp = NULL; > + local_unp_rights = 0; > + > UNP_LIST_LOCK(); > - UNP_PCB_LOCK(unp); > LIST_REMOVE(unp, unp_link); > unp->unp_gencnt = ++unp_gencnt; > --unp_count; > UNP_LIST_UNLOCK(); > > + if ((unp->unp_flags & UNP_NASCENT) != 0) { > + UNP_PCB_LOCK(unp); > + goto teardown; > + } > + UNP_LINK_WLOCK(); > + UNP_PCB_LOCK(unp); > + > /* > * XXXRW: Should assert vp->v_socket == so. > */ > @@ -687,6 +697,7 @@ uipc_detach(struct socket *so) > } > local_unp_rights = unp_rights; > UNP_LINK_WUNLOCK(); > +teardown: > unp->unp_socket->so_pcb = NULL; > saved_unp_addr = unp->unp_addr; > unp->unp_addr = NULL; > @@ -1473,6 +1484,7 @@ unp_connect2(struct socket *so, struct s > > if (so2->so_type != so->so_type) > return (EPROTOTYPE); > + unp2->unp_flags &= ~UNP_NASCENT; > unp->unp_conn = unp2; > > switch (so->so_type) { > > Modified: head/sys/sys/unpcb.h > ============================================================================== > --- head/sys/sys/unpcb.h Mon Aug 8 20:23:11 2016 (r303854) > +++ head/sys/sys/unpcb.h Mon Aug 8 20:25:04 2016 (r303855) > @@ -103,11 +103,6 @@ struct unpcb { > #define UNP_WANTCRED 0x004 /* credentials wanted */ > #define UNP_CONNWAIT 0x008 /* connect blocks until accepted */ > > -#define UNPGC_REF 0x1 /* unpcb has external ref. */ > -#define UNPGC_DEAD 0x2 /* unpcb might be dead. */ > -#define UNPGC_SCANNED 0x4 /* Has been scanned. */ > -#define UNPGC_IGNORE_RIGHTS 0x8 /* Attached rights are freed */ > - > /* > * These flags are used to handle non-atomicity in connect() and bind() > * operations on a socket: in particular, to avoid races between multiple > @@ -115,6 +110,15 @@ struct unpcb { > */ > #define UNP_CONNECTING 0x010 /* Currently connecting. */ > #define UNP_BINDING 0x020 /* Currently binding. */ > +#define UNP_NASCENT 0x040 /* Newborn child socket. */ > + > +/* > + * Flags in unp_gcflag. > + */ > +#define UNPGC_REF 0x1 /* unpcb has external ref. */ > +#define UNPGC_DEAD 0x2 /* unpcb might be dead. */ > +#define UNPGC_SCANNED 0x4 /* Has been scanned. */ > +#define UNPGC_IGNORE_RIGHTS 0x8 /* Attached rights are freed */ > > #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb)) > > _______________________________________________ > svn-src-head@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/svn-src-head > To unsubscribe, send any mail to "svn-src-head-unsubscribe@freebsd.org"
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAPQ4ffsmwTAL%2Bv9RgY8e_%2Bn5CZKKL9ejNntuSNM71MQma5_o2w>