diff options
| author | Kuniyuki Iwashima <kuniyu@google.com> | 2025-07-16 22:08:17 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-17 16:25:21 -0700 |
| commit | dd103c9a53752d3754a3182ec8dd97885680cfe2 (patch) | |
| tree | a7c72c07baf447fdb412409f2673b0425f082aaf | |
| parent | b9c89fa128fa41e56300434dfca1138459b29384 (diff) | |
neighbour: Remove __pneigh_lookup().
__pneigh_lookup() is the lockless version of pneigh_lookup(),
but its only caller pndisc_is_router() holds the table lock and
reads pneigh_netry.flags.
This is because accessing pneigh_entry after pneigh_lookup() was
illegal unless the caller holds RTNL or the table lock.
Now, pneigh_entry is guaranteed to be alive during the RCU critical
section.
Let's call pneigh_lookup() and use READ_ONCE() for n->flags in
pndisc_is_router() and remove __pneigh_lookup().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250716221221.442239-13-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/net/neighbour.h | 2 | ||||
| -rw-r--r-- | net/core/neighbour.c | 11 | ||||
| -rw-r--r-- | net/ipv6/ndisc.c | 6 |
3 files changed, 2 insertions, 17 deletions
diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 6d7f9aa53a7a..f8c7261cd4eb 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -381,8 +381,6 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, struct sk_buff *skb); struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); -struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, - const void *key, struct net_device *dev); struct pneigh_entry *pneigh_create(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, diff --git a/net/core/neighbour.c b/net/core/neighbour.c index b76ff416b9a7..e7bd8111f97f 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -737,17 +737,6 @@ static struct pneigh_entry *__pneigh_lookup_1(struct pneigh_entry *n, return NULL; } -struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, - struct net *net, const void *pkey, struct net_device *dev) -{ - unsigned int key_len = tbl->key_len; - u32 hash_val = pneigh_hash(pkey, key_len); - - return __pneigh_lookup_1(rcu_dereference_protected(tbl->phash_buckets[hash_val], 1), - net, pkey, key_len, dev); -} -EXPORT_SYMBOL_GPL(__pneigh_lookup); - struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *pkey, struct net_device *dev) diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index a3ac26c1df6d..7d5abb3158ec 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -768,11 +768,9 @@ static int pndisc_is_router(const void *pkey, struct pneigh_entry *n; int ret = -1; - read_lock_bh(&nd_tbl.lock); - n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); + n = pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); if (n) - ret = !!(n->flags & NTF_ROUTER); - read_unlock_bh(&nd_tbl.lock); + ret = !!(READ_ONCE(n->flags) & NTF_ROUTER); return ret; } |