[PATCH v1 net 13/15] net: Fix a data-race around sysctl_net_busy_read.

From: Kuniyuki Iwashima
Date: Tue Aug 16 2022 - 04:06:48 EST


While reading sysctl_net_busy_read, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 2d48d67fa8cd ("net: poll/select low latency socket support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
---
CC: Eliezer Tamir <eliezer.tamir@xxxxxxxxxxxxxxx>
---
net/core/sock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 95abf4604d88..788c1372663c 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3367,7 +3367,7 @@ void sock_init_data(struct socket *sock, struct sock *sk)

#ifdef CONFIG_NET_RX_BUSY_POLL
sk->sk_napi_id = 0;
- sk->sk_ll_usec = sysctl_net_busy_read;
+ sk->sk_ll_usec = READ_ONCE(sysctl_net_busy_read);
#endif

sk->sk_max_pacing_rate = ~0UL;
--
2.30.2