diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-07-20 00:28:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-27 09:44:42 +0300 |
| commit | a5c30a51876470499b068f752a89621f52a0d5e3 (patch) | |
| tree | 014b5ee5b8069f109dd2a5682e72c5311d217b69 | |
| parent | 93715448f1162a54e86f93c18c6b4bb8a86bf4d9 (diff) | |
| download | linux-a5c30a51876470499b068f752a89621f52a0d5e3.tar.xz | |
tcp: annotate data-races around tp->keepalive_probes
[ Upstream commit 6e5e1de616bf5f3df1769abc9292191dfad9110a ]
do_tcp_getsockopt() reads tp->keepalive_probes 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/20230719212857.3943972-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/net/tcp.h | 9 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 5 |
2 files changed, 10 insertions, 4 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 428f84f6e0d0..be81a930b91f 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1475,9 +1475,14 @@ static inline int keepalive_time_when(const struct tcp_sock *tp) static inline int keepalive_probes(const struct tcp_sock *tp) { struct net *net = sock_net((struct sock *)tp); + int val; + + /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt() + * and do_tcp_setsockopt(). + */ + val = READ_ONCE(tp->keepalive_probes); - return tp->keepalive_probes ? : - READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); + return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); } static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index b5a05b098414..80212bb0400c 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3138,7 +3138,8 @@ int tcp_sock_set_keepcnt(struct sock *sk, int val) return -EINVAL; lock_sock(sk); - tcp_sk(sk)->keepalive_probes = val; + /* Paired with READ_ONCE() in keepalive_probes() */ + WRITE_ONCE(tcp_sk(sk)->keepalive_probes, val); release_sock(sk); return 0; } @@ -3330,7 +3331,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, if (val < 1 || val > MAX_TCP_KEEPCNT) err = -EINVAL; else - tp->keepalive_probes = val; + WRITE_ONCE(tp->keepalive_probes, val); break; case TCP_SYNCNT: if (val < 1 || val > MAX_TCP_SYNCNT) |