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| author | Eric Dumazet <edumazet@google.com> | 2023-07-19 21:28:55 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-27 08:47:04 +0200 |
| commit | 6b88371f000fa65ecc19bfdc542b64682f11aaa8 (patch) | |
| tree | 0bb76885b0b68e85a66f821a57638c747f637935 | |
| parent | 4f0a31f7325865a0a76a89cc06e9021965f82cf7 (diff) | |
| download | linux-6b88371f000fa65ecc19bfdc542b64682f11aaa8.tar.gz linux-6b88371f000fa65ecc19bfdc542b64682f11aaa8.tar.bz2 linux-6b88371f000fa65ecc19bfdc542b64682f11aaa8.zip | |
tcp: annotate data-races around tp->notsent_lowat
[ Upstream commit 1aeb87bc1440c5447a7fa2d6e3c2cca52cbd206b ]
tp->notsent_lowat can be read locklessly from do_tcp_getsockopt()
and tcp_poll().
Fixes: c9bee3b7fdec ("tcp: TCP_NOTSENT_LOWAT socket option")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-10-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 | 6 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 4 |
2 files changed, 7 insertions, 3 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index fe58b089f0b1..d8920f84f0a8 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2012,7 +2012,11 @@ void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) { struct net *net = sock_net((struct sock *)tp); - return tp->notsent_lowat ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); + u32 val; + + val = READ_ONCE(tp->notsent_lowat); + + return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); } bool tcp_stream_memory_free(const struct sock *sk, int wake); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 29661f7e372d..95e3e32d211a 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3669,7 +3669,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, err = tcp_repair_set_window(tp, optval, optlen); break; case TCP_NOTSENT_LOWAT: - tp->notsent_lowat = val; + WRITE_ONCE(tp->notsent_lowat, val); sk->sk_write_space(sk); break; case TCP_INQ: @@ -4161,7 +4161,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level, val = tcp_time_stamp_raw() + tp->tsoffset; break; case TCP_NOTSENT_LOWAT: - val = tp->notsent_lowat; + val = READ_ONCE(tp->notsent_lowat); break; case TCP_INQ: val = tp->recvmsg_inq; |