struct fib_nh->nh_dev can be NULL, so we should check it before calling
__in_dev_get_rcu on it.
Multiple places seem to want this (and check the return value), so we can
add a convenience wrapper for this.
This fixes a crash in AF_NETLINK sendmsg().
Please double check that I caught all the callers that need the NULL
guard.
Fixes: 0eeb075fad73 ("net: ipv4 sysctl option to ignore routes when nexthop
link is down")
Cc: Andy Gospodarek <go...@cumulusnetworks.com>
Cc: Dinesh Dutt <dd...@cumulusnetworks.com>
Cc: Scott Feldman <sfel...@gmail.com>
Cc: David S. Miller <da...@davemloft.net>
Signed-off-by: Vegard Nossum <vegard.nos...@oracle.com>
---
include/linux/inetdevice.h | 7 +++++++
net/ipv4/fib_semantics.c | 8 ++++----
2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index ee971f3..2d8bea1 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -222,6 +222,13 @@ static inline struct in_device *__in_dev_get_rtnl(const
struct net_device *dev)
return rtnl_dereference(dev->ip_ptr);
}
+static inline struct in_device *in_dev_get_rtnl(const struct net_device *dev)
+{
+ if (!dev)
+ return NULL;
+ return __in_dev_get_rtnl(dev);
+}
+
static inline struct neigh_parms *__in_dev_arp_parms_get_rcu(const struct
net_device *dev)
{
struct in_device *in_dev = __in_dev_get_rcu(dev);
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index d09173b..8289799 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -545,7 +545,7 @@ static void fib_rebalance(struct fib_info *fi)
if (nh->nh_flags & RTNH_F_DEAD)
continue;
- in_dev = __in_dev_get_rtnl(nh->nh_dev);
+ in_dev = in_dev_get_rtnl(nh->nh_dev);
if (in_dev &&
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
@@ -559,7 +559,7 @@ static void fib_rebalance(struct fib_info *fi)
change_nexthops(fi) {
int upper_bound;
- in_dev = __in_dev_get_rtnl(nexthop_nh->nh_dev);
+ in_dev = in_dev_get_rtnl(nexthop_nh->nh_dev);
if (nexthop_nh->nh_flags & RTNH_F_DEAD) {
upper_bound = -1;
@@ -1261,7 +1261,7 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32
seq, int event,
nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif))
goto nla_put_failure;
if (fi->fib_nh->nh_flags & RTNH_F_LINKDOWN) {
- in_dev = __in_dev_get_rtnl(fi->fib_nh->nh_dev);
+ in_dev = in_dev_get_rtnl(fi->fib_nh->nh_dev);
if (in_dev &&
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev))
rtm->rtm_flags |= RTNH_F_DEAD;
@@ -1292,7 +1292,7 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32
seq, int event,
rtnh->rtnh_flags = nh->nh_flags & 0xFF;
if (nh->nh_flags & RTNH_F_LINKDOWN) {
- in_dev = __in_dev_get_rtnl(nh->nh_dev);
+ in_dev = in_dev_get_rtnl(nh->nh_dev);
if (in_dev &&
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev))
rtnh->rtnh_flags |= RTNH_F_DEAD;
--
1.9.1
