5.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 288efe8606b62d0753ba6722b36ef241877251fd ]
sk->sk_ack_backlog can be read without any lock being held. We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing and/or potential KCSAN warnings.
Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 4d5c70e6155d ("sctp: ensure sk_state is set to CLOSED if hashing fails in sctp_listen_start") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/sock.h | 6 +++--- net/ipv4/tcp.c | 2 +- net/ipv4/tcp_diag.c | 2 +- net/ipv4/tcp_ipv4.c | 2 +- net/ipv6/tcp_ipv6.c | 2 +- net/sched/em_meta.c | 2 +- net/sctp/diag.c | 2 +- 7 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h index 250d5a6c508cb..c0d5775bc62c0 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -873,17 +873,17 @@ static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
static inline void sk_acceptq_removed(struct sock *sk) { - sk->sk_ack_backlog--; + WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1); }
static inline void sk_acceptq_added(struct sock *sk) { - sk->sk_ack_backlog++; + WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1); }
static inline bool sk_acceptq_is_full(const struct sock *sk) { - return sk->sk_ack_backlog > sk->sk_max_ack_backlog; + return READ_ONCE(sk->sk_ack_backlog) > sk->sk_max_ack_backlog; }
/* diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 54399256a4380..4800422169f95 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3280,7 +3280,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) * tcpi_unacked -> Number of children ready for accept() * tcpi_sacked -> max backlog */ - info->tcpi_unacked = sk->sk_ack_backlog; + info->tcpi_unacked = READ_ONCE(sk->sk_ack_backlog); info->tcpi_sacked = sk->sk_max_ack_backlog; return; } diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c index 549506162ddec..edfbab54c46f4 100644 --- a/net/ipv4/tcp_diag.c +++ b/net/ipv4/tcp_diag.c @@ -21,7 +21,7 @@ static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, struct tcp_info *info = _info;
if (inet_sk_state_load(sk) == TCP_LISTEN) { - r->idiag_rqueue = sk->sk_ack_backlog; + r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog); r->idiag_wqueue = sk->sk_max_ack_backlog; } else if (sk->sk_type == SOCK_STREAM) { const struct tcp_sock *tp = tcp_sk(sk); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index a0a4dbcf8c12f..1f8a9b323a0dd 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2500,7 +2500,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
state = inet_sk_state_load(sk); if (state == TCP_LISTEN) - rx_queue = sk->sk_ack_backlog; + rx_queue = READ_ONCE(sk->sk_ack_backlog); else /* Because we don't lock the socket, * we might find a transient negative value. diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 81b7ef21180bf..8be41d6c4278b 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1921,7 +1921,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
state = inet_sk_state_load(sp); if (state == TCP_LISTEN) - rx_queue = sp->sk_ack_backlog; + rx_queue = READ_ONCE(sp->sk_ack_backlog); else /* Because we don't lock the socket, * we might find a transient negative value. diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c index ad007cdcec978..c4c297627feac 100644 --- a/net/sched/em_meta.c +++ b/net/sched/em_meta.c @@ -521,7 +521,7 @@ META_COLLECTOR(int_sk_ack_bl) *err = -1; return; } - dst->value = sk->sk_ack_backlog; + dst->value = READ_ONCE(sk->sk_ack_backlog); }
META_COLLECTOR(int_sk_max_ack_bl) diff --git a/net/sctp/diag.c b/net/sctp/diag.c index 2d0318a7352c2..e0785592fdd63 100644 --- a/net/sctp/diag.c +++ b/net/sctp/diag.c @@ -416,7 +416,7 @@ static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc); r->idiag_wqueue = infox->asoc->sndbuf_used; } else { - r->idiag_rqueue = sk->sk_ack_backlog; + r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog); r->idiag_wqueue = sk->sk_max_ack_backlog; } if (infox->sctpinfo)