Commit 1328f39a authored by linke li's avatar linke li Committed by Zhengchao Shao
Browse files

net: mark racy access on sk->sk_rcvbuf 

stable inclusion
from stable-v4.19.314
commit 9e7538cb8131946817218f793ceb334c63cfcdb8
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IA7IEQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9e7538cb8131946817218f793ceb334c63cfcdb8



--------------------------------

[ Upstream commit c2deb2e971f5d9aca941ef13ee05566979e337a4 ]

sk->sk_rcvbuf in __sock_queue_rcv_skb() and __sk_receive_skb() can be
changed by other threads. Mark this as benign using READ_ONCE().

This patch is aimed at reducing the number of benign races reported by
KCSAN in order to focus future debugging effort on harmful races.

Signed-off-by: default avatarlinke li <lilinke99@qq.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarZhengchao Shao <shaozhengchao@huawei.com>
parent 919baa6b

net/core/sock.c

+2 −2
Original line number Diff line number Diff line
@@ -404,7 +404,7 @@ int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 
	unsigned long flags;

	struct sk_buff_head *list = &sk->sk_receive_queue;



	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {

	if (atomic_read(&sk->sk_rmem_alloc) >= READ_ONCE(sk->sk_rcvbuf)) {

		atomic_inc(&sk->sk_drops);

		trace_sock_rcvqueue_full(sk, skb);

		return -ENOMEM;
@@ -456,7 +456,7 @@ int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, 


	skb->dev = NULL;



	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {

	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {

		atomic_inc(&sk->sk_drops);

		goto discard_and_relse;

	}