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 B707314389C; Wed, 19 Jun 2024 13:13:41 +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=1718802821; cv=none; b=e4FIRvTtus3aO1NpWehwGsbyPUZlok0ND3G4TFapMATMhnmuoxGON8VRC6cme2yLGKawNN4qas0VLYUJ9BpGN9qVq4MkUmiPO0MvbvnZx6TvpW8l8XqOdRBURsnqigYHwCoLkPzNmF28exPD+sRcp28XEJtnLYfa7SPzBmx6qb4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718802821; c=relaxed/simple; bh=Arq88Fhe1gJV3A4j9szl9+8SVDxaTMPD/DJeFhz8k4s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QjOvruEbc5MtssCtbLS/f+jRhTbm72CH4X7OWFLt2ei2wDmBL+dYvzYPijge2dkNFzCjZRum9WFgV32Q0x8NGOBB51T9Bk08QJLwldYphalNzHo5uZ9/1aQTE0wzFPLsjFkHIERbkyd0Cda7UVIuAFpYkSRMr1QTPZBsKt4ma5g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LeXJKqF3; 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="LeXJKqF3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B781C2BBFC; Wed, 19 Jun 2024 13:13:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718802821; bh=Arq88Fhe1gJV3A4j9szl9+8SVDxaTMPD/DJeFhz8k4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LeXJKqF3GGFbVfr7Vub/ii8KVi64RzLgrm55+ilpr1euQv9Sj2oMHUPQeQUiFK/5S tD/pOfuNkg3CAYmOZ4WI7k3ZEIGND+6hxxS3sY5VcSWkOcEcZ4Jfuprrp+WNA/SgCf XXesCKSZS8TGJ4xX277HfXjym3wHhJCgez6Ho14w= 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 6.9 059/281] af_unix: Annotate data-race of sk->sk_state in unix_inq_len(). Date: Wed, 19 Jun 2024 14:53:38 +0200 Message-ID: <20240619125612.119715128@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240619125609.836313103@linuxfoundation.org> References: <20240619125609.836313103@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.9-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 0a9c3975d4303..989c2c76dce66 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -3064,7 +3064,7 @@ 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