]> git.ipfire.org Git - thirdparty/kernel/stable-queue.git/commitdiff
4.14-stable patches
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 13 Sep 2021 08:43:03 +0000 (10:43 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 13 Sep 2021 08:43:03 +0000 (10:43 +0200)
added patches:
netns-protect-netns-id-lookups-with-rcu.patch

queue-4.14/netns-protect-netns-id-lookups-with-rcu.patch [new file with mode: 0644]
queue-4.14/series

diff --git a/queue-4.14/netns-protect-netns-id-lookups-with-rcu.patch b/queue-4.14/netns-protect-netns-id-lookups-with-rcu.patch
new file mode 100644 (file)
index 0000000..caa4d02
--- /dev/null
@@ -0,0 +1,84 @@
+From 2dce224f469f060b9998a5a869151ef83c08ce77 Mon Sep 17 00:00:00 2001
+From: Guillaume Nault <gnault@redhat.com>
+Date: Mon, 13 Jan 2020 22:39:22 +0100
+Subject: netns: protect netns ID lookups with RCU
+
+From: Guillaume Nault <gnault@redhat.com>
+
+commit 2dce224f469f060b9998a5a869151ef83c08ce77 upstream.
+
+__peernet2id() can be protected by RCU as it only calls idr_for_each(),
+which is RCU-safe, and never modifies the nsid table.
+
+rtnl_net_dumpid() can also do lockless lookups. It does two nested
+idr_for_each() calls on nsid tables (one direct call and one indirect
+call because of rtnl_net_dumpid_one() calling __peernet2id()). The
+netnsid tables are never updated. Therefore it is safe to not take the
+nsid_lock and run within an RCU-critical section instead.
+
+Signed-off-by: Guillaume Nault <gnault@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: HÃ¥kon Bugge <haakon.bugge@oracle.com>
+
+---
+ net/core/net_namespace.c |   18 ++++++++++--------
+ 1 file changed, 10 insertions(+), 8 deletions(-)
+
+--- a/net/core/net_namespace.c
++++ b/net/core/net_namespace.c
+@@ -181,9 +181,9 @@ static int net_eq_idr(int id, void *net,
+       return 0;
+ }
+-/* Should be called with nsid_lock held. If a new id is assigned, the bool alloc
+- * is set to true, thus the caller knows that the new id must be notified via
+- * rtnl.
++/* Must be called from RCU-critical section or with nsid_lock held. If
++ * a new id is assigned, the bool alloc is set to true, thus the
++ * caller knows that the new id must be notified via rtnl.
+  */
+ static int __peernet2id_alloc(struct net *net, struct net *peer, bool *alloc)
+ {
+@@ -207,7 +207,7 @@ static int __peernet2id_alloc(struct net
+       return NETNSA_NSID_NOT_ASSIGNED;
+ }
+-/* should be called with nsid_lock held */
++/* Must be called from RCU-critical section or with nsid_lock held */
+ static int __peernet2id(struct net *net, struct net *peer)
+ {
+       bool no = false;
+@@ -240,9 +240,10 @@ int peernet2id(struct net *net, struct n
+ {
+       int id;
+-      spin_lock_bh(&net->nsid_lock);
++      rcu_read_lock();
+       id = __peernet2id(net, peer);
+-      spin_unlock_bh(&net->nsid_lock);
++      rcu_read_unlock();
++
+       return id;
+ }
+ EXPORT_SYMBOL(peernet2id);
+@@ -761,6 +762,7 @@ struct rtnl_net_dump_cb {
+       int s_idx;
+ };
++/* Runs in RCU-critical section. */
+ static int rtnl_net_dumpid_one(int id, void *peer, void *data)
+ {
+       struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
+@@ -791,9 +793,9 @@ static int rtnl_net_dumpid(struct sk_buf
+               .s_idx = cb->args[0],
+       };
+-      spin_lock_bh(&net->nsid_lock);
++      rcu_read_lock();
+       idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
+-      spin_unlock_bh(&net->nsid_lock);
++      rcu_read_unlock();
+       cb->args[0] = net_cb.idx;
+       return skb->len;
index af9d713844a2c209987af06240ec6d5443e762f8..d98c0fb25660e4ffc35cf776aa1b0e03ba8239e2 100644 (file)
@@ -89,3 +89,4 @@ bcma-fix-memory-leak-for-internally-handled-cores.patch
 ipv4-make-exception-cache-less-predictible.patch
 net-sched-fix-qdisc_rate_table-refcount-leak-when-ge.patch
 net-qualcomm-fix-qca7000-checksum-handling.patch
+netns-protect-netns-id-lookups-with-rcu.patch