From 6f605b57f3782114e330e108ce1903ede22ec675 Mon Sep 17 00:00:00 2001
From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Mon, 11 Jul 2022 17:15:21 -0700
Subject: tcp: Fix a data-race around sysctl_max_tw_buckets.
While reading sysctl_max_tw_buckets, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/inet_timewait_sock.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
(limited to 'net')
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 0ec501845cb3..47ccc343c9fb 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -156,7 +156,8 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
{
struct inet_timewait_sock *tw;
- if (refcount_read(&dr->tw_refcount) - 1 >= dr->sysctl_max_tw_buckets)
+ if (refcount_read(&dr->tw_refcount) - 1 >=
+ READ_ONCE(dr->sysctl_max_tw_buckets))
return NULL;
tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab,
--
cgit v1.2.3