6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jakub Kicinski <kuba@xxxxxxxxxx>
commit d1cacd74776895f6435941f86a1130e58f6dd226 upstream.
The NAPI IDs were not fully exposed to user space prior to the netlink
API, so they were never namespaced. The netlink API must ensure that
at the very least NAPI instance belongs to the same netns as the owner
of the genl sock.
napi_by_id() can become static now, but it needs to move because of
dev_get_by_napi_id().
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 1287c1ae0fc2 ("netdev-genl: Support setting per-NAPI config values")
Fixes: 27f91aaf49b3 ("netdev-genl: Add netlink framework functions for napi")
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@xxxxxxxxx>
Reviewed-by: Joe Damato <jdamato@xxxxxxxxxx>
Link: https://patch.msgid.link/20250106180137.1861472-1-kuba@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/dev.c | 43 ++++++++++++++++++++++++++++++-------------
net/core/dev.h | 3 ++-
net/core/netdev-genl.c | 4 +---
3 files changed, 33 insertions(+), 17 deletions(-)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -753,6 +753,36 @@ int dev_fill_forward_path(const struct n
}
EXPORT_SYMBOL_GPL(dev_fill_forward_path);
+/* must be called under rcu_read_lock(), as we dont take a reference */
+static struct napi_struct *napi_by_id(unsigned int napi_id)
+{
+ unsigned int hash = napi_id % HASH_SIZE(napi_hash);
+ struct napi_struct *napi;
+
+ hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
+ if (napi->napi_id == napi_id)
+ return napi;
+
+ return NULL;
+}
+
+/* must be called under rcu_read_lock(), as we dont take a reference */
+struct napi_struct *netdev_napi_by_id(struct net *net, unsigned int napi_id)
+{
+ struct napi_struct *napi;
+
+ napi = napi_by_id(napi_id);
+ if (!napi)
+ return NULL;
+
+ if (WARN_ON_ONCE(!napi->dev))
+ return NULL;
+ if (!net_eq(net, dev_net(napi->dev)))
+ return NULL;
+
+ return napi;
+}
+
/**
* __dev_get_by_name - find a device by its name
* @net: the applicable net namespace
@@ -6291,19 +6321,6 @@ bool napi_complete_done(struct napi_stru
}
EXPORT_SYMBOL(napi_complete_done);
-/* must be called under rcu_read_lock(), as we dont take a reference */
-struct napi_struct *napi_by_id(unsigned int napi_id)
-{
- unsigned int hash = napi_id % HASH_SIZE(napi_hash);
- struct napi_struct *napi;
-
- hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
- if (napi->napi_id == napi_id)
- return napi;
-
- return NULL;
-}
-
static void skb_defer_free_flush(struct softnet_data *sd)
{
struct sk_buff *skb, *next;
--- a/net/core/dev.h
+++ b/net/core/dev.h
@@ -22,6 +22,8 @@ struct sd_flow_limit {
extern int netdev_flow_limit_table_len;
+struct napi_struct *netdev_napi_by_id(struct net *net, unsigned int napi_id);
+
#ifdef CONFIG_PROC_FS
int __init dev_proc_init(void);
#else
@@ -146,7 +148,6 @@ void xdp_do_check_flushed(struct napi_st
static inline void xdp_do_check_flushed(struct napi_struct *napi) { }
#endif
-struct napi_struct *napi_by_id(unsigned int napi_id);
void kick_defer_list_purge(struct softnet_data *sd, unsigned int cpu);
#define XMIT_RECURSION_LIMIT 8
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -164,8 +164,6 @@ netdev_nl_napi_fill_one(struct sk_buff *
void *hdr;
pid_t pid;
- if (WARN_ON_ONCE(!napi->dev))
- return -EINVAL;
if (!(napi->dev->flags & IFF_UP))
return 0;
@@ -216,7 +214,7 @@ int netdev_nl_napi_get_doit(struct sk_bu
rtnl_lock();
rcu_read_lock();
- napi = napi_by_id(napi_id);
+ napi = netdev_napi_by_id(genl_info_net(info), napi_id);
if (napi) {
err = netdev_nl_napi_fill_one(rsp, napi, info);
} else {
