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authorEric Dumazet <edumazet@google.com>2023-07-20 00:28:50 +0300
committerJakub Kicinski <kuba@kernel.org>2023-07-20 22:34:18 +0300
commit5ecf9d4f52ff2f1d4d44c9b68bc75688e82f13b4 (patch)
tree05188d2c1d64e0c751d5ee48a9523a631efa5a62
parent4164245c76ff906c9086758e1c3f87082a7f5ef5 (diff)
downloadlinux-5ecf9d4f52ff2f1d4d44c9b68bc75688e82f13b4.tar.xz
tcp: annotate data-races around tp->keepalive_intvl
do_tcp_getsockopt() reads tp->keepalive_intvl while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--include/net/tcp.h9
-rw-r--r--net/ipv4/tcp.c4
2 files changed, 9 insertions, 4 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 9e1c3337cdfe..2d8d58dec652 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1509,9 +1509,14 @@ void tcp_leave_memory_pressure(struct sock *sk);
static inline int keepalive_intvl_when(const struct tcp_sock *tp)
{
struct net *net = sock_net((struct sock *)tp);
+ int val;
+
+ /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl()
+ * and do_tcp_setsockopt().
+ */
+ val = READ_ONCE(tp->keepalive_intvl);
- return tp->keepalive_intvl ? :
- READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl);
+ return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl);
}
static inline int keepalive_time_when(const struct tcp_sock *tp)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index b4f7856dfb16..d55fe014e7c9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3345,7 +3345,7 @@ int tcp_sock_set_keepintvl(struct sock *sk, int val)
return -EINVAL;
lock_sock(sk);
- tcp_sk(sk)->keepalive_intvl = val * HZ;
+ WRITE_ONCE(tcp_sk(sk)->keepalive_intvl, val * HZ);
release_sock(sk);
return 0;
}
@@ -3559,7 +3559,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
if (val < 1 || val > MAX_TCP_KEEPINTVL)
err = -EINVAL;
else
- tp->keepalive_intvl = val * HZ;
+ WRITE_ONCE(tp->keepalive_intvl, val * HZ);
break;
case TCP_KEEPCNT:
if (val < 1 || val > MAX_TCP_KEEPCNT)