From 67edf21e5adfd336f2ff08668eb09850943666d3 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Mon, 10 Sep 2018 17:21:42 -0700 Subject: [PATCH] scsi: libcxgbi: fib6_ino reference in rt6_info is rcu protected The fib6_info reference in rt6_info is rcu protected. Add a helper to extract prefsrc from and update cxgbi_check_route6 to use it. Fixes: 0153167aebd0 ("net/ipv6: Remove rt6i_prefsrc") Reported-by: kbuild test robot Signed-off-by: David Ahern Signed-off-by: David S. Miller --- drivers/scsi/cxgbi/libcxgbi.c | 5 ++--- include/net/ip6_fib.h | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c index 6b3ea50..75f8764 100644 --- a/drivers/scsi/cxgbi/libcxgbi.c +++ b/drivers/scsi/cxgbi/libcxgbi.c @@ -784,7 +784,8 @@ cxgbi_check_route6(struct sockaddr *dst_addr, int ifindex) csk->mtu = mtu; csk->dst = dst; - if (!rt->from || ipv6_addr_any(&rt->from->fib6_prefsrc.addr)) { + rt6_get_prefsrc(rt, &pref_saddr); + if (ipv6_addr_any(&pref_saddr)) { struct inet6_dev *idev = ip6_dst_idev((struct dst_entry *)rt); err = ipv6_dev_get_saddr(&init_net, idev ? idev->dev : NULL, @@ -794,8 +795,6 @@ cxgbi_check_route6(struct sockaddr *dst_addr, int ifindex) &daddr6->sin6_addr); goto rel_rt; } - } else { - pref_saddr = rt->from->fib6_prefsrc.addr; } csk->csk_family = AF_INET6; diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index c749666..f06e968 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -412,6 +412,25 @@ int fib6_add(struct fib6_node *root, struct fib6_info *rt, struct nl_info *info, struct netlink_ext_ack *extack); int fib6_del(struct fib6_info *rt, struct nl_info *info); +static inline +void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) +{ + const struct fib6_info *from; + + rcu_read_lock(); + + from = rcu_dereference(rt->from); + if (from) { + *addr = from->fib6_prefsrc.addr; + } else { + struct in6_addr in6_zero = {}; + + *addr = in6_zero; + } + + rcu_read_unlock(); +} + static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i) { return f6i->fib6_nh.nh_dev; -- 2.7.4