diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-07-20 00:28:51 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-07-20 22:34:18 +0300 |
| commit | 6e5e1de616bf5f3df1769abc9292191dfad9110a (patch) | |
| tree | aa2f5769684948278bd811c96b96845ec6b1fc4d | |
| parent | 5ecf9d4f52ff2f1d4d44c9b68bc75688e82f13b4 (diff) | |
| download | linux-6e5e1de616bf5f3df1769abc9292191dfad9110a.tar.xz | |
tcp: annotate data-races around tp->keepalive_probes
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>
| -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 2d8d58dec652..a8b93b2875ea 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1533,9 +1533,14 @@ 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 d55fe014e7c9..574fd0da1673 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3357,7 +3357,8 @@ 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; } @@ -3565,7 +3566,7 @@ 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) |