From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from forward502d.mail.yandex.net (forward502d.mail.yandex.net [178.154.239.210]) (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 CF44B1A9B24; Tue, 19 Nov 2024 11:04:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.210 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732014295; cv=none; b=gV1FbCZd3+nHEw4V2LVO1CJkIuMWgFSsPHnkvi3VK02MojtlJif22NNaXOut3nb7DJnKyWRLWMDnwpBZ6SNo1oGVjKHiOFRAhrw9jjHQBjiRM3Wo1F4/IywKfiv0RXMatjV9zH9U6CD/VZV6cWmBRuLInGQoNSgGL3N/tagoEWY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732014295; c=relaxed/simple; bh=/SYL9YbS6GATrA0PjR2LaEJi7M8ZYPBqjDcB5/e5lWA=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=P3tMYqS9Z5KUywQxiM02Qkjvn5Yb7YnUgVTJ9t5ybillYR/50A7KO0jfu3mmVTooaZWwpp4J1+GvIeqBrc41SjMrusl4oNBlHuKGgfixgqDkL37qE8mmWm2Otg77iJKlAHdYsv33oCymKemuLQyLonAo5CznVmAQM5ue+9943Kg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=yandex.ru; spf=pass smtp.mailfrom=yandex.ru; dkim=pass (1024-bit key) header.d=yandex.ru header.i=@yandex.ru header.b=el/LTpl8; arc=none smtp.client-ip=178.154.239.210 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=yandex.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=yandex.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=yandex.ru header.i=@yandex.ru header.b="el/LTpl8" Received: from mail-nwsmtp-smtp-production-main-95.klg.yp-c.yandex.net (mail-nwsmtp-smtp-production-main-95.klg.yp-c.yandex.net [IPv6:2a02:6b8:c42:874b:0:640:bc97:0]) by forward502d.mail.yandex.net (Yandex) with ESMTPS id B8F48611D7; Tue, 19 Nov 2024 14:04:44 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-main-95.klg.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id f4PlBZmOjuQ0-1kWMGczu; Tue, 19 Nov 2024 14:04:43 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1732014283; bh=PlfJvw3vZ0B7dANA7HsxSHEs+NvmIVeH1x4Q/ETIw7U=; h=In-Reply-To:Cc:Date:References:To:Subject:From:Message-ID; b=el/LTpl8wCPFL0hrUZ3zY/XZ6fFV6uX+PX7JM080sImHuiOFQ79BD7EuvIN24KheS SvWskZgwfOLIatlCQvOxwZIaxSoY4ixUjbZv7W8rzkHlqF7kPMHNUgoESF9fUjeCcF n09RfKn8xAVSG6thQpo23Y1/aQ9u8bcsB0UXk3sA= Authentication-Results: mail-nwsmtp-smtp-production-main-95.klg.yp-c.yandex.net; dkim=pass header.i=@yandex.ru Message-ID: <67638eaf-3d94-450a-8280-df4f7dc66ce7@yandex.ru> Date: Tue, 19 Nov 2024 14:04:41 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: stsp Subject: Re: [PATCH v2] net/unix: pass pidfd flags via SCM_PIDFD cmsg To: Kuniyuki Iwashima Cc: almasrymina@google.com, asml.silence@gmail.com, axboe@kernel.dk, brauner@kernel.org, cyphar@cyphar.com, davem@davemloft.net, edumazet@google.com, gouhao@uniontech.com, horms@kernel.org, kees@kernel.org, krisman@suse.de, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, mhal@rbox.co, netdev@vger.kernel.org, oleg@redhat.com, pabeni@redhat.com, quic_abchauha@quicinc.com, shuah@kernel.org, tandersen@netflix.com, viro@zeniv.linux.org.uk, willemb@google.com References: <20241114091909.3552288-1-stsp2@yandex.ru> <20241116011038.94912-1-kuniyu@amazon.com> Content-Language: en-US In-Reply-To: <20241116011038.94912-1-kuniyu@amazon.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 16.11.2024 04:10, Kuniyuki Iwashima пишет: > Now this allows sending pidfd without SO_PASSPIDFD, so you need to > add a validation for "if (!msg->msg_control)" in __scm_recv_common(). Will do, thanks. Btw don't we need MSG_CTRUNC in such case even if "msg_control"exists? Or the established practice is to just drop cmsg silently? I mean, something like the below: --- a/include/net/scm.h +++ b/include/net/scm.h @@ -176,12 +176,19 @@ static inline bool __scm_recv_common(struct socket *sock, struct msghdr *msg,         if (!msg->msg_control) {                 if (test_bit(SOCK_PASSCRED, &sock->flags) ||                     test_bit(SOCK_PASSPIDFD, &sock->flags) || -                   scm->fp || scm_has_secdata(sock)) +                   scm->fp || scm_has_secdata(sock) || +                   scm->pidfd_flags)                         msg->msg_flags |= MSG_CTRUNC;                 scm_destroy(scm);                 return false;         } +       if (!test_bit(SOCK_PASSPIDFD, &sock->flags) && scm->pidfd_flags) { +               msg->msg_flags |= MSG_CTRUNC; +               scm_destroy(scm); +               return false; +       } +         if (test_bit(SOCK_PASSCRED, &sock->flags)) {                 struct user_namespace *current_ns = current_user_ns();                 struct ucred ucreds = {