inetpeer: fix a race in inetpeer_gc_worker()
commit 5faa5df1fa2024 (inetpeer: Invalidate the inetpeer tree along with
the routing cache) added a race :
Before freeing an inetpeer, we must respect a RCU grace period, and make
sure no user will attempt to increase refcnt.
inetpeer_invalidate_tree() waits for a RCU grace period before inserting
inetpeer tree into gc_list and waking the worker. At that time, no
concurrent lookup can find a inetpeer in this tree.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index b94765e..2040bff 100644
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -40,7 +40,10 @@
u32 pmtu_orig;
u32 pmtu_learned;
struct inetpeer_addr_base redirect_learned;
- struct list_head gc_list;
+ union {
+ struct list_head gc_list;
+ struct rcu_head gc_rcu;
+ };
/*
* Once inet_peer is queued for deletion (refcnt == -1), following fields
* are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp