From af67508ea6cbf0e4ea27f8120056fa2efce127dd Mon Sep 17 00:00:00 2001
From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Tue, 23 Aug 2022 10:46:56 -0700
Subject: [PATCH] net: Fix data-races around
sysctl_fb_tunnels_only_for_init_net.
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>
---
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 1a3cb93c3dcce..6d3a33fd0cdb3 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)
--
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