From 81fa352902e1cf85531f1b6b409592f17dd7ccc2 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 2 Nov 2022 15:33:33 +0800 Subject: [PATCH] tcp: Fix a data-race around sysctl_tcp_max_orphans. stable inclusion from stable-v5.10.132 commit 6481a8a72a746dc96e3aa70a9f9f6d3daf0f88c2 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5YS3T Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6481a8a72a746dc96e3aa70a9f9f6d3daf0f88c2 -------------------------------- [ Upstream commit 47e6ab24e8c6e3ca10ceb5835413f401f90de4bf ] While reading sysctl_tcp_max_orphans, it can be changed concurrently. So, we need to add READ_ONCE() to avoid a data-race. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Zheng Zengkai Acked-by: Xie XiuQi --- net/ipv4/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e7183cc8e998..1270772cb1f3 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2494,7 +2494,8 @@ static void tcp_orphan_update(struct timer_list *unused) static bool tcp_too_many_orphans(int shift) { - return READ_ONCE(tcp_orphan_cache) << shift > sysctl_tcp_max_orphans; + return READ_ONCE(tcp_orphan_cache) << shift > + READ_ONCE(sysctl_tcp_max_orphans); } bool tcp_check_oom(struct sock *sk, int shift) -- GitLab