From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from forward500a.mail.yandex.net (forward500a.mail.yandex.net [178.154.239.80]) (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 7ED911C68B2; Tue, 19 Nov 2024 11:03:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732014210; cv=none; b=XfkMAzEI1ny77/KbpnxzdTLJzkR7MhJtgge+c87SL5qgH97jqVMMB+zgiRrlNxDRaRAI9TMC/Jh+2n0lOb9ZTDAEUmXtQaEtrM7bHwOGmODnx1z8lWgiy9L24fUzDXZXpr8oGQAiMTHJ0HwUq7gLEBIedkhmxiR43UmZPYs4s2s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732014210; c=relaxed/simple; bh=aJ5K2q9mqNSqTCgXLexrzoLohS/CKe1+e+l1a0CAFX8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=VV3woKmIqqg5wYmMnatnRu6YeMJPdEaFOwU1pkjhBoN6Vkp0S817FtdiuTACCh/Q8tX40PGqRpjOvDFJK3bzeTnMaQvwHWkAxbvwdTHcI3TKd0JOW6qmcZWToMkrTTMlf5/LhJM1hjuANnbVJSuB9ZEd9fb5yCga/khPTvXjoNE= 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=PxttJcsg; arc=none smtp.client-ip=178.154.239.80 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="PxttJcsg" Received: from mail-nwsmtp-smtp-production-main-81.vla.yp-c.yandex.net (mail-nwsmtp-smtp-production-main-81.vla.yp-c.yandex.net [IPv6:2a02:6b8:c15:339a:0:640:a002:0]) by forward500a.mail.yandex.net (Yandex) with ESMTPS id D8A89613BF; Tue, 19 Nov 2024 14:03:19 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-main-81.vla.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id H3PcixrOpa60-LLeEi36o; Tue, 19 Nov 2024 14:03:18 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1732014198; bh=exOOjxGX9sMW0VLoYv1+HLZua1oxjjGv4JrDpnhbuc4=; h=From:In-Reply-To:Cc:Date:References:To:Subject:Message-ID; b=PxttJcsgethQmC8dPISISo6PA4S6ClNmXZMlR4V9AkQnJy0xpeSOcoWS7IUL34zXY Zmw2tPi/zaar7cQ36yHJHiSHDtvxpzNSugDSCS2NGIM8u48eow3UE0Fsf3qLBYq1Tg 2ee37Y9Y4XcmkyekWEvxWYMooXBP6ZGJ/ezj7VZs= Authentication-Results: mail-nwsmtp-smtp-production-main-81.vla.yp-c.yandex.net; dkim=pass header.i=@yandex.ru Message-ID: Date: Tue, 19 Nov 2024 14:03:16 +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 Subject: Re: [PATCH v2] net/unix: pass pidfd flags via SCM_PIDFD cmsg Content-Language: en-US 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> From: stsp 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 = {