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Merge branch 'ipv6-couple-of-fixes-for-rcu-change-to-from' 

David Ahern says:

====================
net/ipv6: couple of fixes for rcu change to from

So many details... I am thankful for all the robots running the
permutations and tools.

Two bug fixes from the rcu change to rt->from:
1. missing rcu lock in ip6_negative_advice
2. rcu dereferences in 2 sites
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2018-04-23 16:12:55 -04:00
parent 40cde8249a 8a14e46f14
commit f7c3b12cec
1 changed files with 12 additions and 5 deletions
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17
net/ipv6/route.c
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@ -1541,11 +1541,13 @@ static struct rt6_info *rt6_find_cached_rt(struct fib6_info *rt,
static int rt6_remove_exception_rt(struct rt6_info *rt)
{
struct rt6_exception_bucket *bucket;
struct fib6_info *from = rt->from;
struct in6_addr *src_key = NULL;
struct rt6_exception *rt6_ex;
struct fib6_info *from;
int err;
from = rcu_dereference_protected(rt->from,
lockdep_is_held(&rt6_exception_lock));
if (!from ||
!(rt->rt6i_flags & RTF_CACHE))
return -EINVAL;
@ -2201,10 +2203,12 @@ static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
if (rt) {
if (rt->rt6i_flags & RTF_CACHE) {
rcu_read_lock();
if (rt6_check_expired(rt)) {
rt6_remove_exception_rt(rt);
dst = NULL;
}
rcu_read_unlock();
} else {
dst_release(dst);
dst = NULL;
@ -2221,6 +2225,7 @@ static void ip6_link_failure(struct sk_buff *skb)
rt = (struct rt6_info *) skb_dst(skb);
if (rt) {
rcu_read_lock();
if (rt->rt6i_flags & RTF_CACHE) {
if (dst_hold_safe(&rt->dst))
rt6_remove_exception_rt(rt);
@ -2228,15 +2233,14 @@ static void ip6_link_failure(struct sk_buff *skb)
struct fib6_info *from;
struct fib6_node *fn;
rcu_read_lock();
from = rcu_dereference(rt->from);
if (from) {
fn = rcu_dereference(from->fib6_node);
if (fn && (rt->rt6i_flags & RTF_DEFAULT))
fn->fn_sernum = -1;
}
rcu_read_unlock();
}
rcu_read_unlock();
}
}
@ -3338,8 +3342,10 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
rcu_read_lock();
from = rcu_dereference(rt->from);
nrt = ip6_rt_cache_alloc(from, &msg->dest, NULL);
fib6_info_hold(from);
rcu_read_unlock();
nrt = ip6_rt_cache_alloc(from, &msg->dest, NULL);
if (!nrt)
goto out;
@ -3353,7 +3359,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
* a cached route because rt6_insert_exception() will
* takes care of it
*/
if (rt6_insert_exception(nrt, rt->from)) {
if (rt6_insert_exception(nrt, from)) {
dst_release_immediate(&nrt->dst);
goto out;
}
@ -3365,6 +3371,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
out:
fib6_info_release(from);
neigh_release(neigh);
}