From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E84343925B for ; Wed, 7 Jun 2023 20:23:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F432C433EF; Wed, 7 Jun 2023 20:23:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1686169410; bh=tJqtBH4fn64myua2srtXJ6ayq8rQYVN5KLj+vRMTzJw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FGfMIeCrAsrMj5XTX9/+dB4283USmLBhvQrDJQSDmpxtaVH9XEnK7NAdVLPL7h4MR fu+M4vZJBs2lHPhi+TZ48Yh9EM1ffbvjgS1qfJBwBIb/dIl838lwgEMrQGOvZI5iws ZqV9RdpEQIwnBiP6VJdi+YnEGlMEoI11hy5j+xvo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jakub Kicinski , Simon Horman , "David S. Miller" , Sasha Levin Subject: [PATCH 6.3 039/286] tls: improve lockless access safety of tls_err_abort() Date: Wed, 7 Jun 2023 22:12:18 +0200 Message-ID: <20230607200924.306887174@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230607200922.978677727@linuxfoundation.org> References: <20230607200922.978677727@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jakub Kicinski [ 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 Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 6e6a7c37d685c..1a53c8f481e9a 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -70,7 +70,9 @@ 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); } -- 2.39.2