From: Kuniyuki Iwashima <kuniyu@amazon.com> 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) -- 2.25.1