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 9C911157E62; Wed, 3 Jul 2024 11:00:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004425; cv=none; b=rtB39O6CmBxjTUR4l5beG/keqXzYYdIzHwSDGbgquyUQlKgqEwzJvPl+iZUa0XK7Ya48QRUEFCAxhCU+lR2GOxRFZfzNmQUNMmOP6JNWQDidOiPA1ltJTZYK2sp2zvZn5hTe5OwLywzvwHoc48xb0u1r3K+HmKtuKJjeeBXqqXo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004425; c=relaxed/simple; bh=KKzjblYYinsoxFmV5/qDldKqE6oXsyIccq58GzC0keQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cdnNi8/w56qU9XDkDEW4B3vOXCILuzBtNC2DeUMQY4oelaxXil3IUXAUPS08/Pf111WGckcAPbb3r4ePQzY9zcfhL06rnx/4L9gUjhiHitH+JjNc4juEDWk7KZaCFv3Y99sDCX5hF/ykupJdeOqeO/Y960+vn+Oei7GHlhPz0NY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kcTgH3Pe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kcTgH3Pe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2042BC2BD10; Wed, 3 Jul 2024 11:00:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720004425; bh=KKzjblYYinsoxFmV5/qDldKqE6oXsyIccq58GzC0keQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kcTgH3PehlnVwwsnv+WltPs0koOOS0TSaqp8/9DrsrdzYSlr4ii+8E/jGbrvzCrdu SRxG0a3coniHRXQRQxoC9Mo+MF9tz3Lt9eWE3YfA6NKseqN29eobT0BRSfSnZZqn3+ jBgQ7vZXwdVhMjXB+wZ75jVftVsvvh/DHHh2fhBU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kuniyuki Iwashima , Paolo Abeni , Sasha Levin Subject: [PATCH 5.10 020/290] af_unix: Annotate data-race of sk->sk_state in unix_inq_len(). Date: Wed, 3 Jul 2024 12:36:41 +0200 Message-ID: <20240703102904.955112396@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102904.170852981@linuxfoundation.org> References: <20240703102904.170852981@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kuniyuki Iwashima [ Upstream commit 3a0f38eb285c8c2eead4b3230c7ac2983707599d ] ioctl(SIOCINQ) calls unix_inq_len() that checks sk->sk_state first and returns -EINVAL if it's TCP_LISTEN. Then, for SOCK_STREAM sockets, unix_inq_len() returns the number of bytes in recvq. However, unix_inq_len() does not hold unix_state_lock(), and the concurrent listen() might change the state after checking sk->sk_state. If the race occurs, 0 is returned for the listener, instead of -EINVAL, because the length of skb with embryo is 0. We could hold unix_state_lock() in unix_inq_len(), but it's overkill given the result is true for pre-listen() TCP_CLOSE state. So, let's use READ_ONCE() for sk->sk_state in unix_inq_len(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/unix/af_unix.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 3ab726a668e8a..c2aaf4b832c65 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2614,7 +2614,7 @@ long unix_inq_len(struct sock *sk) struct sk_buff *skb; long amount = 0; - if (sk->sk_state == TCP_LISTEN) + if (READ_ONCE(sk->sk_state) == TCP_LISTEN) return -EINVAL; spin_lock(&sk->sk_receive_queue.lock); -- 2.43.0