Commit 83fe28b1 authored by Eric Dumazet's avatar Eric Dumazet Committed by sanglipeng
Browse files

tcp: annotate data-races around tp->keepalive_probes 

stable inclusion
from stable-v5.10.188
commit a5c30a51876470499b068f752a89621f52a0d5e3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8KYFP

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a5c30a51876470499b068f752a89621f52a0d5e3



--------------------------------

[ Upstream commit 6e5e1de6 ]

do_tcp_getsockopt() reads tp->keepalive_probes while another cpu
might change its value.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-6-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarsanglipeng <sanglipeng1@jd.com>
parent bcf23282

include/net/tcp.h

+7 −2
Original line number Diff line number Diff line
@@ -1477,9 +1477,14 @@ 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)

net/ipv4/tcp.c

+3 −2
Original line number Diff line number Diff line
@@ -3137,7 +3137,8 @@ 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;

}
@@ -3329,7 +3330,7 @@ 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)