From 80413eaa8949654be763eeb5f725a4552f2b1df0 Mon Sep 17 00:00:00 2001
From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Tue, 11 Oct 2022 12:14:01 +0000
Subject: [PATCH] net: Fix a data-race around sysctl_net_busy_poll.
stable inclusion
from stable-v4.19.257
commit da89cab514b3ec7fdedb378617160c47fe3b60a9
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5UQH4
CVE: NA
--------------------------------
[ Upstream commit c42b7cddea47503411bfb5f2f93a4154aaffa2d9 ]
While reading sysctl_net_busy_poll, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 060212928670 ("net: add low latency socket poll")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>
---
include/net/busy_poll.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index c76a5e9894da..8f42f6f3af86 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -43,7 +43,7 @@ extern unsigned int sysctl_net_busy_poll __read_mostly;
static inline bool net_busy_loop_on(void)
{
- return sysctl_net_busy_poll;
+ return READ_ONCE(sysctl_net_busy_poll);
}
static inline bool sk_can_busy_loop(const struct sock *sk)
--
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