svn commit: r346530 - in head/sys: netinet netinet6
Hans Petter Selasky
hselasky at FreeBSD.org
Mon Apr 22 07:27:26 UTC 2019
Author: hselasky
Date: Mon Apr 22 07:27:24 2019
New Revision: 346530
URL: https://svnweb.freebsd.org/changeset/base/346530
Log:
Fix panic in network stack due to memory use after free in relation to
fragmented packets.
When sending IPv4 and IPv6 fragmented packets and a fragment is lost,
the mbuf making up the fragment will remain in the temporary hashed
fragment list for a while. If the network interface departs before the
so-called slow timeout clears the packet, the fragment causes a panic
when the timeout kicks in due to accessing a freed network interface
structure.
Make sure that when a network device is departing, all hashed IPv4 and
IPv6 fragments belonging to it, get freed.
Backtrace:
panic()
icmp6_reflect()
hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
^^^^ rcvif->if_afdata[AF_INET6] is NULL.
icmp6_error()
frag6_freef()
frag6_slowtimo()
pfslowtimo()
softclock_call_cc()
softclock()
ithread_loop()
Differential Revision: https://reviews.freebsd.org/D19622
Reviewed by: bz (network), adrian
MFC after: 1 week
Sponsored by: Mellanox Technologies
Modified:
head/sys/netinet/ip_reass.c
head/sys/netinet6/frag6.c
Modified: head/sys/netinet/ip_reass.c
==============================================================================
--- head/sys/netinet/ip_reass.c Mon Apr 22 07:17:10 2019 (r346529)
+++ head/sys/netinet/ip_reass.c Mon Apr 22 07:27:24 2019 (r346530)
@@ -46,7 +46,10 @@ __FBSDID("$FreeBSD$");
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <net/if_var.h>
#include <net/rss_config.h>
#include <net/netisr.h>
#include <net/vnet.h>
@@ -605,6 +608,37 @@ ipreass_drain(void)
IPQ_UNLOCK(i);
}
}
+
+/*
+ * Drain off all datagram fragments belonging to
+ * the given network interface.
+ */
+static void
+ipreass_cleanup(void *arg __unused, struct ifnet *ifp)
+{
+ struct ipq *fp, *temp;
+ struct mbuf *m;
+ int i;
+
+ KASSERT(ifp != NULL, ("%s: ifp is NULL", __func__));
+
+ CURVNET_SET_QUIET(ifp->if_vnet);
+ for (i = 0; i < IPREASS_NHASH; i++) {
+ IPQ_LOCK(i);
+ /* Scan fragment list. */
+ TAILQ_FOREACH_SAFE(fp, &V_ipq[i].head, ipq_list, temp) {
+ for (m = fp->ipq_frags; m != NULL; m = m->m_nextpkt) {
+ if (m->m_pkthdr.rcvif == ifp) {
+ ipq_drop(&V_ipq[i], fp);
+ break;
+ }
+ }
+ }
+ IPQ_UNLOCK(i);
+ }
+ CURVNET_RESTORE();
+}
+EVENTHANDLER_DEFINE(ifnet_departure_event, ipreass_cleanup, NULL, 0);
#ifdef VIMAGE
/*
Modified: head/sys/netinet6/frag6.c
==============================================================================
--- head/sys/netinet6/frag6.c Mon Apr 22 07:17:10 2019 (r346529)
+++ head/sys/netinet6/frag6.c Mon Apr 22 07:27:24 2019 (r346530)
@@ -81,7 +81,7 @@ static void frag6_deq(struct ip6asfrag *, uint32_t buc
static void frag6_insque_head(struct ip6q *, struct ip6q *,
uint32_t bucket);
static void frag6_remque(struct ip6q *, uint32_t bucket);
-static void frag6_freef(struct ip6q *, uint32_t bucket);
+static void frag6_freef(struct ip6q *, uint32_t bucket, bool send_icmp);
struct ip6qbucket {
struct ip6q ip6q;
@@ -594,7 +594,7 @@ insert:
if (af6->ip6af_off != next) {
if (q6->ip6q_nfrag > V_ip6_maxfragsperpacket) {
IP6STAT_ADD(ip6s_fragdropped, q6->ip6q_nfrag);
- frag6_freef(q6, hash);
+ frag6_freef(q6, hash, true);
}
IP6Q_UNLOCK(hash);
return IPPROTO_DONE;
@@ -604,7 +604,7 @@ insert:
if (af6->ip6af_up->ip6af_mff) {
if (q6->ip6q_nfrag > V_ip6_maxfragsperpacket) {
IP6STAT_ADD(ip6s_fragdropped, q6->ip6q_nfrag);
- frag6_freef(q6, hash);
+ frag6_freef(q6, hash, true);
}
IP6Q_UNLOCK(hash);
return IPPROTO_DONE;
@@ -731,7 +731,7 @@ insert:
* associated datagrams.
*/
static void
-frag6_freef(struct ip6q *q6, uint32_t bucket)
+frag6_freef(struct ip6q *q6, uint32_t bucket, bool send_icmp)
{
struct ip6asfrag *af6, *down6;
@@ -748,7 +748,7 @@ frag6_freef(struct ip6q *q6, uint32_t bucket)
* Return ICMP time exceeded error for the 1st fragment.
* Just free other fragments.
*/
- if (af6->ip6af_off == 0) {
+ if (af6->ip6af_off == 0 && send_icmp != false) {
struct ip6_hdr *ip6;
/* adjust pointer */
@@ -864,7 +864,7 @@ frag6_slowtimo(void)
IP6STAT_ADD(ip6s_fragtimeout,
q6->ip6q_prev->ip6q_nfrag);
/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
- frag6_freef(q6->ip6q_prev, i);
+ frag6_freef(q6->ip6q_prev, i, true);
}
}
/*
@@ -883,7 +883,7 @@ frag6_slowtimo(void)
IP6STAT_ADD(ip6s_fragoverflow,
q6->ip6q_prev->ip6q_nfrag);
/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
- frag6_freef(head->ip6q_prev, i);
+ frag6_freef(head->ip6q_prev, i, true);
}
IP6Q_UNLOCK(i);
}
@@ -901,7 +901,7 @@ frag6_slowtimo(void)
IP6STAT_ADD(ip6s_fragoverflow,
q6->ip6q_prev->ip6q_nfrag);
/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
- frag6_freef(head->ip6q_prev, i);
+ frag6_freef(head->ip6q_prev, i, true);
}
IP6Q_UNLOCK(i);
i = (i + 1) % IP6REASS_NHASH;
@@ -931,7 +931,7 @@ frag6_drain(void)
while (head->ip6q_next != head) {
IP6STAT_INC(ip6s_fragdropped);
/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
- frag6_freef(head->ip6q_next, i);
+ frag6_freef(head->ip6q_next, i, true);
}
IP6Q_UNLOCK(i);
}
@@ -939,6 +939,45 @@ frag6_drain(void)
}
VNET_LIST_RUNLOCK_NOSLEEP();
}
+
+/*
+ * Drain off all datagram fragments belonging to
+ * the given network interface.
+ */
+static void
+frag6_cleanup(void *arg __unused, struct ifnet *ifp)
+{
+ struct ip6q *q6, *q6n, *head;
+ struct ip6asfrag *af6;
+ struct mbuf *m;
+ int i;
+
+ KASSERT(ifp != NULL, ("%s: ifp is NULL", __func__));
+
+ CURVNET_SET_QUIET(ifp->if_vnet);
+ for (i = 0; i < IP6REASS_NHASH; i++) {
+ IP6Q_LOCK(i);
+ head = IP6Q_HEAD(i);
+ /* Scan fragment list. */
+ for (q6 = head->ip6q_next; q6 != head; q6 = q6n) {
+ q6n = q6->ip6q_next;
+
+ for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
+ af6 = af6->ip6af_down) {
+ m = IP6_REASS_MBUF(af6);
+
+ if (m->m_pkthdr.rcvif == ifp) {
+ IP6STAT_INC(ip6s_fragdropped);
+ frag6_freef(q6, i, false);
+ break;
+ }
+ }
+ }
+ IP6Q_UNLOCK(i);
+ }
+ CURVNET_RESTORE();
+}
+EVENTHANDLER_DEFINE(ifnet_departure_event, frag6_cleanup, NULL, 0);
int
ip6_deletefraghdr(struct mbuf *m, int offset, int wait)
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