6.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit bc1fb82ae11753c5dec53c667a055dc37796dbd2 ]
sk_getsockopt() runs locklessly. This means sk->sk_lingertime
can be read while other threads are changing its value.
Other reads also happen without socket lock being held,
and must be annotated.
Remove preprocessor logic using BITS_PER_LONG, compilers
are smart enough to figure this by themselves.
v2: fixed a clang W=1 (-Wtautological-constant-out-of-range-compare) warning
(Jakub)
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/bluetooth/iso.c | 2 +-
net/bluetooth/sco.c | 2 +-
net/core/sock.c | 18 +++++++++---------
net/sched/em_meta.c | 2 +-
net/smc/af_smc.c | 2 +-
5 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index cd07836850758..00e93ae6373da 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -1486,7 +1486,7 @@ static int iso_sock_release(struct socket *sock)
iso_sock_close(sk);
- if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
+ if (sock_flag(sk, SOCK_LINGER) && READ_ONCE(sk->sk_lingertime) &&
!(current->flags & PF_EXITING)) {
lock_sock(sk);
err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 7762604ddfc05..99b149261949a 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -1267,7 +1267,7 @@ static int sco_sock_release(struct socket *sock)
sco_sock_close(sk);
- if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
+ if (sock_flag(sk, SOCK_LINGER) && READ_ONCE(sk->sk_lingertime) &&
!(current->flags & PF_EXITING)) {
lock_sock(sk);
err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
diff --git a/net/core/sock.c b/net/core/sock.c
index ddcf0630cc3ee..b2083a359ec10 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -793,7 +793,7 @@ EXPORT_SYMBOL(sock_set_reuseport);
void sock_no_linger(struct sock *sk)
{
lock_sock(sk);
- sk->sk_lingertime = 0;
+ WRITE_ONCE(sk->sk_lingertime, 0);
sock_set_flag(sk, SOCK_LINGER);
release_sock(sk);
}
@@ -1226,15 +1226,15 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
ret = -EFAULT;
break;
}
- if (!ling.l_onoff)
+ if (!ling.l_onoff) {
sock_reset_flag(sk, SOCK_LINGER);
- else {
-#if (BITS_PER_LONG == 32)
- if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
- sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
+ } else {
+ unsigned long t_sec = ling.l_linger;
+
+ if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
+ WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
else
-#endif
- sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
+ WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
sock_set_flag(sk, SOCK_LINGER);
}
break;
@@ -1680,7 +1680,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname,
case SO_LINGER:
lv = sizeof(v.ling);
v.ling.l_onoff = sock_flag(sk, SOCK_LINGER);
- v.ling.l_linger = sk->sk_lingertime / HZ;
+ v.ling.l_linger = READ_ONCE(sk->sk_lingertime) / HZ;
break;
case SO_BSDCOMPAT:
diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c
index 6fdba069f6bfd..da34fd4c92695 100644
--- a/net/sched/em_meta.c
+++ b/net/sched/em_meta.c
@@ -502,7 +502,7 @@ META_COLLECTOR(int_sk_lingertime)
*err = -1;
return;
}
- dst->value = sk->sk_lingertime / HZ;
+ dst->value = READ_ONCE(sk->sk_lingertime) / HZ;
}
META_COLLECTOR(int_sk_err_qlen)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index f94e7a04e33d0..462ece6bb1802 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1820,7 +1820,7 @@ void smc_close_non_accepted(struct sock *sk)
lock_sock(sk);
if (!sk->sk_lingertime)
/* wait for peer closing */
- sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
+ WRITE_ONCE(sk->sk_lingertime, SMC_MAX_STREAM_WAIT_TIMEOUT);
__smc_release(smc);
release_sock(sk);
sock_put(sk); /* sock_hold above */
--
2.40.1
