6.1-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 5.19.6 / net-fix-data-races-around-sysctl_fb_tunnels_only_for.patch

From 371d28cecdf9fc70b8a830cac7566c83b38d4526 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Tue, 23 Aug 2022 10:46:56 -0700
Subject: net: Fix data-races around sysctl_fb_tunnels_only_for_init_net.

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit af67508ea6cbf0e4ea27f8120056fa2efce127dd ]

While reading sysctl_fb_tunnels_only_for_init_net, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: 79134e6ce2c9 ("net: do not create fallback tunnels for non-default namespaces")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/linux/netdevice.h | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 2563d30736e9a..78dd63a5c7c80 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -640,9 +640,14 @@ extern int sysctl_devconf_inherit_init_net;
  */
 static inline bool net_has_fallback_tunnels(const struct net *net)
 {
-	return !IS_ENABLED(CONFIG_SYSCTL) ||
-	       !sysctl_fb_tunnels_only_for_init_net ||
-	       (net == &init_net && sysctl_fb_tunnels_only_for_init_net == 1);
+#if IS_ENABLED(CONFIG_SYSCTL)
+	int fb_tunnels_only_for_init_net = READ_ONCE(sysctl_fb_tunnels_only_for_init_net);
+
+	return !fb_tunnels_only_for_init_net ||
+		(net_eq(net, &init_net) && fb_tunnels_only_for_init_net == 1);
+#else
+	return true;
+#endif
 }
 
 static inline int netdev_queue_numa_node_read(const struct netdev_queue *q)
-- 
2.35.1