[src/trunk]: src/sys/net Protect IFADDR_READER_FOREACH and obtained ifa with ...

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/8785f8912744
branches:  trunk
changeset: 828006:8785f8912744
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Wed Nov 22 05:42:30 2017 +0000

description:
Protect IFADDR_READER_FOREACH and obtained ifa with psz/psref

diffstat:

 sys/net/if_spppsubr.c |  26 +++++++++++++++++++++-----
 1 files changed, 21 insertions(+), 5 deletions(-)

diffs (94 lines):

diff -r 781b95162b50 -r 8785f8912744 sys/net/if_spppsubr.c
--- a/sys/net/if_spppsubr.c     Wed Nov 22 05:17:32 2017 +0000
+++ b/sys/net/if_spppsubr.c     Wed Nov 22 05:42:30 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_spppsubr.c,v 1.172 2017/11/15 07:52:58 knakahara Exp $       */
+/*     $NetBSD: if_spppsubr.c,v 1.173 2017/11/22 05:42:30 ozaki-r Exp $         */
 
 /*
  * Synchronous PPP/Cisco link level subroutines.
@@ -41,7 +41,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.172 2017/11/15 07:52:58 knakahara Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.173 2017/11/22 05:42:30 ozaki-r Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -5219,6 +5219,8 @@
        struct ifaddr *ifa;
        struct sockaddr_in *si, *sm;
        uint32_t ssrc, ddst;
+       int s;
+       struct psref psref;
 
        sm = NULL;
        ssrc = ddst = 0;
@@ -5227,14 +5229,18 @@
         * aliases don't make any sense on a p2p link anyway.
         */
        si = 0;
+       s = pserialize_read_enter();
        IFADDR_READER_FOREACH(ifa, ifp) {
                if (ifa->ifa_addr->sa_family == AF_INET) {
                        si = (struct sockaddr_in *)ifa->ifa_addr;
                        sm = (struct sockaddr_in *)ifa->ifa_netmask;
-                       if (si)
+                       if (si) {
+                               ifa_acquire(ifa, &psref);
                                break;
+                       }
                }
        }
+       pserialize_read_exit(s);
        if (ifa) {
                if (si && si->sin_addr.s_addr) {
                        ssrc = si->sin_addr.s_addr;
@@ -5245,6 +5251,7 @@
                si = (struct sockaddr_in *)ifa->ifa_dstaddr;
                if (si && si->sin_addr.s_addr)
                        ddst = si->sin_addr.s_addr;
+               ifa_release(ifa, &psref);
        }
 
        if (dst) *dst = ntohl(ddst);
@@ -5457,6 +5464,8 @@
        struct ifaddr *ifa;
        struct sockaddr_in6 *si, *sm;
        struct in6_addr ssrc, ddst;
+       int s;
+       struct psref psref;
 
        sm = NULL;
        memset(&ssrc, 0, sizeof(ssrc));
@@ -5466,13 +5475,19 @@
         * aliases don't make any sense on a p2p link anyway.
         */
        si = 0;
-       IFADDR_READER_FOREACH(ifa, ifp)
+       s = pserialize_read_enter();
+       IFADDR_READER_FOREACH(ifa, ifp) {
                if (ifa->ifa_addr->sa_family == AF_INET6) {
                        si = (struct sockaddr_in6 *)ifa->ifa_addr;
                        sm = (struct sockaddr_in6 *)ifa->ifa_netmask;
-                       if (si && IN6_IS_ADDR_LINKLOCAL(&si->sin6_addr))
+                       if (si && IN6_IS_ADDR_LINKLOCAL(&si->sin6_addr)) {
+                               ifa_acquire(ifa, &psref);
                                break;
+                       }
                }
+       }
+       pserialize_read_exit(s);
+
        if (ifa) {
                if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr)) {
                        memcpy(&ssrc, &si->sin6_addr, sizeof(ssrc));
@@ -5485,6 +5500,7 @@
                si = (struct sockaddr_in6 *)ifa->ifa_dstaddr;
                if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr))
                        memcpy(&ddst, &si->sin6_addr, sizeof(ddst));
+               ifa_release(ifa, &psref);
        }
 
        if (dst)