netdev - [PATCH v3 net-next 11/15] neighbour: Use rcu_dereference() in pneigh_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250716221221.442239-12-kuniyu@google.com>
Date: Wed, 16 Jul 2025 22:08:16 +0000
From: Kuniyuki Iwashima <kuniyu@...gle.com>
To: "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, 
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, David Ahern <dsahern@...nel.org>
Cc: Simon Horman <horms@...nel.org>, Kuniyuki Iwashima <kuniyu@...gle.com>, 
	Kuniyuki Iwashima <kuni1840@...il.com>, netdev@...r.kernel.org
Subject: [PATCH v3 net-next 11/15] neighbour: Use rcu_dereference() in pneigh_get_{first,next}().

Now pneigh_entry is guaranteed to be alive during the
RCU critical section even without holding tbl->lock.

Let's use rcu_dereference() in pneigh_get_{first,next}().

Note that neigh_seq_start() still holds tbl->lock for the
normal neighbour entry.

Signed-off-by: Kuniyuki Iwashima <kuniyu@...gle.com>
---
 net/core/neighbour.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index c7e0611219710..27650f52d659d 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -3309,10 +3309,10 @@ static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
 
 	state->flags |= NEIGH_SEQ_IS_PNEIGH;
 	for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
-		pn = rcu_dereference_protected(tbl->phash_buckets[bucket], 1);
+		pn = rcu_dereference(tbl->phash_buckets[bucket]);
 
 		while (pn && !net_eq(pneigh_net(pn), net))
-			pn = rcu_dereference_protected(pn->next, 1);
+			pn = rcu_dereference(pn->next);
 		if (pn)
 			break;
 	}
@@ -3330,17 +3330,17 @@ static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
 	struct neigh_table *tbl = state->tbl;
 
 	do {
-		pn = rcu_dereference_protected(pn->next, 1);
+		pn = rcu_dereference(pn->next);
 	} while (pn && !net_eq(pneigh_net(pn), net));
 
 	while (!pn) {
 		if (++state->bucket > PNEIGH_HASHMASK)
 			break;
 
-		pn = rcu_dereference_protected(tbl->phash_buckets[state->bucket], 1);
+		pn = rcu_dereference(tbl->phash_buckets[state->bucket]);
 
 		while (pn && !net_eq(pneigh_net(pn), net))
-			pn = rcu_dereference_protected(pn->next, 1);
+			pn = rcu_dereference(pn->next);
 		if (pn)
 			break;
 	}
-- 
2.50.0.727.gbf7dc18ff4-goog