summary refs log tree commit diff
path: root/net
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2017-09-01 14:03:32 -0700
committerDavid S. Miller <davem@davemloft.net>2017-09-01 17:33:17 -0700
commit4cc5b44b29a9de9b3f841efedaa3f769066c63cc (patch)
tree2a98212b93c7c09a10a29c57754f3bc8cde99627 /net
parentbbd9644e84f68587ed136c7e1c56e454c26231ff (diff)
downloadlinux-4cc5b44b29a9de9b3f841efedaa3f769066c63cc.tar.gz
inetpeer: fix RCU lookup()
Excess of seafood or something happened while I cooked the commit
adding RB tree to inetpeer.

Of course, RCU rules need to be respected or bad things can happen.

In this particular loop, we need to read *pp once per iteration, not
twice.

Fixes: b145425f269a ("inetpeer: remove AVL implementation in favor of RB tree")
Reported-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/inetpeer.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index 337ad41bb80a..e7eb590c86ce 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -102,15 +102,18 @@ static struct inet_peer *lookup(const struct inetpeer_addr *daddr,
 				struct rb_node **parent_p,
 				struct rb_node ***pp_p)
 {
-	struct rb_node **pp, *parent;
+	struct rb_node **pp, *parent, *next;
 	struct inet_peer *p;
 
 	pp = &base->rb_root.rb_node;
 	parent = NULL;
-	while (*pp) {
+	while (1) {
 		int cmp;
 
-		parent = rcu_dereference_raw(*pp);
+		next = rcu_dereference_raw(*pp);
+		if (!next)
+			break;
+		parent = next;
 		p = rb_entry(parent, struct inet_peer, rb_node);
 		cmp = inetpeer_addr_cmp(daddr, &p->daddr);
 		if (cmp == 0) {