svn commit: r364073 - in head/sys: netinet netinet6
Hans Petter Selasky
hselasky at FreeBSD.org
Mon Aug 10 10:46:10 UTC 2020
Author: hselasky
Date: Mon Aug 10 10:46:08 2020
New Revision: 364073
URL: https://svnweb.freebsd.org/changeset/base/364073
Log:
Make sure the multicast release tasks are properly drained when
destroying a VNET or a network interface.
Else the inm release tasks, both IPv4 and IPv6 may cause a panic
accessing a freed VNET or network interface.
Reviewed by: jmg@
Discussed with: bz@
Differential Revision: https://reviews.freebsd.org/D24914
MFC after: 1 week
Sponsored by: Mellanox Technologies
Modified:
head/sys/netinet/in.c
head/sys/netinet/in_mcast.c
head/sys/netinet/in_var.h
head/sys/netinet6/in6_ifattach.c
head/sys/netinet6/in6_mcast.c
head/sys/netinet6/in6_var.h
Modified: head/sys/netinet/in.c
==============================================================================
--- head/sys/netinet/in.c Mon Aug 10 10:40:19 2020 (r364072)
+++ head/sys/netinet/in.c Mon Aug 10 10:46:08 2020 (r364073)
@@ -998,6 +998,13 @@ in_ifdetach(struct ifnet *ifp)
in_pcbpurgeif0(&V_ulitecbinfo, ifp);
in_purgemaddrs(ifp);
IN_MULTI_UNLOCK();
+
+ /*
+ * Make sure all multicast deletions invoking if_ioctl() are
+ * completed before returning. Else we risk accessing a freed
+ * ifnet structure pointer.
+ */
+ inm_release_wait(NULL);
}
/*
Modified: head/sys/netinet/in_mcast.c
==============================================================================
--- head/sys/netinet/in_mcast.c Mon Aug 10 10:40:19 2020 (r364072)
+++ head/sys/netinet/in_mcast.c Mon Aug 10 10:46:08 2020 (r364073)
@@ -224,18 +224,37 @@ inm_is_ifp_detached(const struct in_multi *inm)
}
#endif
-static struct task free_task;
+/*
+ * Interface detach can happen in a taskqueue thread context, so we must use a
+ * dedicated thread to avoid deadlocks when draining inm_release tasks.
+ */
+TASKQUEUE_DEFINE_THREAD(inm_free);
+static struct task inm_free_task;
static struct in_multi_head inm_free_list = SLIST_HEAD_INITIALIZER();
static void inm_release_task(void *arg __unused, int pending __unused);
static void
inm_init(void *arg __unused)
{
- TASK_INIT(&free_task, 0, inm_release_task, NULL);
+ TASK_INIT(&inm_free_task, 0, inm_release_task, NULL);
}
SYSINIT(inm_init, SI_SUB_TASKQ, SI_ORDER_ANY, inm_init, NULL);
void
+inm_release_wait(void *arg __unused)
+{
+
+ /*
+ * Make sure all pending multicast addresses are freed before
+ * the VNET or network device is destroyed:
+ */
+ taskqueue_drain(taskqueue_inm_free, &inm_free_task);
+}
+#ifdef VIMAGE
+VNET_SYSUNINIT(inm_release_wait, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, inm_release_wait, NULL);
+#endif
+
+void
inm_release_list_deferred(struct in_multi_head *inmh)
{
@@ -244,7 +263,7 @@ inm_release_list_deferred(struct in_multi_head *inmh)
mtx_lock(&in_multi_free_mtx);
SLIST_CONCAT(&inm_free_list, inmh, in_multi, inm_nrele);
mtx_unlock(&in_multi_free_mtx);
- taskqueue_enqueue(taskqueue_thread, &free_task);
+ taskqueue_enqueue(taskqueue_inm_free, &inm_free_task);
}
void
Modified: head/sys/netinet/in_var.h
==============================================================================
--- head/sys/netinet/in_var.h Mon Aug 10 10:40:19 2020 (r364072)
+++ head/sys/netinet/in_var.h Mon Aug 10 10:46:08 2020 (r364073)
@@ -450,6 +450,7 @@ void inm_print(const struct in_multi *);
int inm_record_source(struct in_multi *inm, const in_addr_t);
void inm_release_deferred(struct in_multi *);
void inm_release_list_deferred(struct in_multi_head *);
+void inm_release_wait(void *);
struct in_multi *
in_addmulti(struct in_addr *, struct ifnet *);
int in_joingroup(struct ifnet *, const struct in_addr *,
Modified: head/sys/netinet6/in6_ifattach.c
==============================================================================
--- head/sys/netinet6/in6_ifattach.c Mon Aug 10 10:40:19 2020 (r364072)
+++ head/sys/netinet6/in6_ifattach.c Mon Aug 10 10:46:08 2020 (r364073)
@@ -871,7 +871,7 @@ in6_purgemaddrs(struct ifnet *ifp)
* completed before returning. Else we risk accessing a freed
* ifnet structure pointer.
*/
- in6m_release_wait();
+ in6m_release_wait(NULL);
}
void
Modified: head/sys/netinet6/in6_mcast.c
==============================================================================
--- head/sys/netinet6/in6_mcast.c Mon Aug 10 10:40:19 2020 (r364072)
+++ head/sys/netinet6/in6_mcast.c Mon Aug 10 10:46:08 2020 (r364073)
@@ -539,10 +539,18 @@ in6m_release_list_deferred(struct in6_multi_head *inmh
}
void
-in6m_release_wait(void)
+in6m_release_wait(void *arg __unused)
{
+
+ /*
+ * Make sure all pending multicast addresses are freed before
+ * the VNET or network device is destroyed:
+ */
taskqueue_drain_all(taskqueue_in6m_free);
}
+#ifdef VIMAGE
+VNET_SYSUNINIT(in6m_release_wait, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, in6m_release_wait, NULL);
+#endif
void
in6m_disconnect_locked(struct in6_multi_head *inmh, struct in6_multi *inm)
Modified: head/sys/netinet6/in6_var.h
==============================================================================
--- head/sys/netinet6/in6_var.h Mon Aug 10 10:40:19 2020 (r364072)
+++ head/sys/netinet6/in6_var.h Mon Aug 10 10:46:08 2020 (r364073)
@@ -870,7 +870,7 @@ void in6m_commit(struct in6_multi *);
void in6m_print(const struct in6_multi *);
int in6m_record_source(struct in6_multi *, const struct in6_addr *);
void in6m_release_list_deferred(struct in6_multi_head *);
-void in6m_release_wait(void);
+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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