From: Jakub Kicinski kuba@kernel.org
[ Upstream commit 8a0d57df8938e9fd2e99d47a85b7f37d86f91097 ]
Most protos' poll() methods insert a memory barrier between writes to sk_err and sk_error_report(). This dates back to commit a4d258036ed9 ("tcp: Fix race in tcp_poll").
I guess we should do the same thing in TLS, tcp_poll() does not hold the socket lock.
Fixes: 3c4d7559159b ("tls: kernel TLS support") Signed-off-by: Jakub Kicinski kuba@kernel.org Reviewed-by: Simon Horman simon.horman@corigine.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_strp.c | 4 +++- net/tls/tls_sw.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c index da95abbb7ea32..f37f4a0fcd3c2 100644 --- a/net/tls/tls_strp.c +++ b/net/tls/tls_strp.c @@ -20,7 +20,9 @@ static void tls_strp_abort_strp(struct tls_strparser *strp, int err) strp->stopped = 1;
/* Report an error on the lower socket */ - strp->sk->sk_err = -err; + WRITE_ONCE(strp->sk->sk_err, -err); + /* Paired with smp_rmb() in tcp_poll() */ + smp_wmb(); sk_error_report(strp->sk); }
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 992092aeebad9..2e5e7853a6101 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -67,7 +67,9 @@ noinline void tls_err_abort(struct sock *sk, int err) { WARN_ON_ONCE(err >= 0); /* sk->sk_err should contain a positive error code. */ - sk->sk_err = -err; + WRITE_ONCE(sk->sk_err, -err); + /* Paired with smp_rmb() in tcp_poll() */ + smp_wmb(); sk_error_report(sk); }