Date: Thu, 24 Jan 2019 08:25:03 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r343394 - head/sys/netinet6 Message-ID: <201901240825.x0O8P3fd070682@repo.freebsd.org>
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Author: hselasky Date: Thu Jan 24 08:25:02 2019 New Revision: 343394 URL: https://svnweb.freebsd.org/changeset/base/343394 Log: When detaching a network interface drain the workqueue freeing the inm's because the destructor will access the if_ioctl() callback in the ifnet pointer which is about to be freed. This prevents use-after-free. PR: 233535 Differential Revision: https://reviews.freebsd.org/D18887 Reviewed by: bz (net) Tested by: ae MFC after: 1 week Sponsored by: Mellanox Technologies Modified: head/sys/netinet6/in6_ifattach.c head/sys/netinet6/in6_mcast.c head/sys/netinet6/in6_var.h Modified: head/sys/netinet6/in6_ifattach.c ============================================================================== --- head/sys/netinet6/in6_ifattach.c Thu Jan 24 08:18:02 2019 (r343393) +++ head/sys/netinet6/in6_ifattach.c Thu Jan 24 08:25:02 2019 (r343394) @@ -884,6 +884,13 @@ in6_purgemaddrs(struct ifnet *ifp) IN6_MULTI_LIST_UNLOCK(); IN6_MULTI_UNLOCK(); in6m_release_list_deferred(&purgeinms); + + /* + * Make sure all multicast deletions invoking if_ioctl() are + * completed before returning. Else we risk accessing a freed + * ifnet structure pointer. + */ + in6m_release_wait(); } void Modified: head/sys/netinet6/in6_mcast.c ============================================================================== --- head/sys/netinet6/in6_mcast.c Thu Jan 24 08:18:02 2019 (r343393) +++ head/sys/netinet6/in6_mcast.c Thu Jan 24 08:25:02 2019 (r343394) @@ -585,6 +585,14 @@ in6m_release_list_deferred(struct in6_multi_head *inmh } void +in6m_release_wait(void) +{ + + /* Wait for all jobs to complete. */ + gtaskqueue_drain_all(free_gtask.gt_taskqueue); +} + +void in6m_disconnect(struct in6_multi *inm) { struct ifnet *ifp; Modified: head/sys/netinet6/in6_var.h ============================================================================== --- head/sys/netinet6/in6_var.h Thu Jan 24 08:18:02 2019 (r343393) +++ head/sys/netinet6/in6_var.h Thu Jan 24 08:25:02 2019 (r343394) @@ -811,6 +811,7 @@ void in6m_print(const struct in6_multi *); int in6m_record_source(struct in6_multi *, const struct in6_addr *); void in6m_release_deferred(struct in6_multi *); void in6m_release_list_deferred(struct in6_multi_head *); +void in6m_release_wait(void); void ip6_freemoptions(struct ip6_moptions *); int ip6_getmoptions(struct inpcb *, struct sockopt *); int ip6_setmoptions(struct inpcb *, struct sockopt *);
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