6.6-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 482ad2a4ace2740ca0ff1cbc8f3c7f862f3ab507 ]
dev->nd_net can change, readers should either use rcu_read_lock() or RTNL.
We currently use a generic helper, dev_net() with no debugging support. We probably have many hidden bugs.
Add dev_net_rcu() helper for callers using rcu_read_lock() protection.
Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: Kuniyuki Iwashima kuniyu@amazon.com Link: https://patch.msgid.link/20250205155120.1676781-2-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 71b8471c93fa ("ipv4: use RCU protection in ipv4_default_advmss()") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/netdevice.h | 6 ++++++ include/net/net_namespace.h | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 8b5121eb8757e..95ee88dfe0b9c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2593,6 +2593,12 @@ struct net *dev_net(const struct net_device *dev) return read_pnet(&dev->nd_net); }
+static inline +struct net *dev_net_rcu(const struct net_device *dev) +{ + return read_pnet_rcu(&dev->nd_net); +} + static inline void dev_net_set(struct net_device *dev, struct net *net) { diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index b767bdcd9e122..ce3f84c6eb8eb 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -389,7 +389,7 @@ static inline struct net *read_pnet(const possible_net_t *pnet) #endif }
-static inline struct net *read_pnet_rcu(possible_net_t *pnet) +static inline struct net *read_pnet_rcu(const possible_net_t *pnet) { #ifdef CONFIG_NET_NS return rcu_dereference(pnet->net);