diff options
| author | Martin Pieuchot <mpi@cvs.openbsd.org> | 2018-01-25 14:47:36 +0000 |
|---|---|---|
| committer | Martin Pieuchot <mpi@cvs.openbsd.org> | 2018-01-25 14:47:36 +0000 |
| commit | c4ca663c8aa85771ec354935314c0470d9f557c2 (patch) | |
| tree | 28a0ffb39d43d5076eeae34a712524068422d41b /sys | |
| parent | 4318a51d24a39bcc62cb7a7ef6feb4082c9e923f (diff) | |
Use a workaround for detached parent in carp_proto_input_c().
A NULL dereference can happen since processing protocol layer is
deffered to a second task. In other words the NET_LOCK() is released
then regrabbed between ip_input() and carp_proto_input().
The same workaround is already in use in carp_output() due to deffered
processing in case of IPsec.
The real fix is to make carp(4) MP-safe and use if_get(9) there, any
taker?
Found & fix tested by Hrvoje Popovski.
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/netinet/ip_carp.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/sys/netinet/ip_carp.c b/sys/netinet/ip_carp.c index 08620190049..c18247cdd98 100644 --- a/sys/netinet/ip_carp.c +++ b/sys/netinet/ip_carp.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ip_carp.c,v 1.327 2018/01/12 23:47:24 dlg Exp $ */ +/* $OpenBSD: ip_carp.c,v 1.328 2018/01/25 14:47:35 mpi Exp $ */ /* * Copyright (c) 2002 Michael Shalayeff. All rights reserved. @@ -601,12 +601,21 @@ carp_proto_input_c(struct ifnet *ifp, struct mbuf *m, struct carp_header *ch, struct timeval sc_tv, ch_tv; struct srpl *cif; - if (ifp->if_type == IFT_CARP) + KERNEL_ASSERT_LOCKED(); /* touching if_carp + carp_vhosts */ + + if (ifp->if_type == IFT_CARP) { + /* + * If the parent of this carp(4) got destroyed while + * `m' was being processed, silently drop it. + */ + if (ifp->if_carpdev == NULL) { + m_freem(m); + return; + } cif = &ifp->if_carpdev->if_carp; - else + } else cif = &ifp->if_carp; - KERNEL_ASSERT_LOCKED(); /* touching if_carp + carp_vhosts */ SRPL_FOREACH_LOCKED(sc, cif, sc_list) { if (af == AF_INET && ismulti != IN_MULTICAST(sc->sc_peer.s_addr)) |