6.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
[ 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@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 */