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 9D08E11CAB for ; Mon, 26 Jun 2023 18:39:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B0B2C433C8; Mon, 26 Jun 2023 18:39:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687804760; bh=SmI0wIclrXG2Z7l2k3a/CF45iPIL4ZMsn8SNR7st0Ww=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U/yXkII/t/cErQ+D5s8JyjyTHGYCuaou4LNv8PdtOOqsMBHTXnyVxfsgIOQCCD/GU 7eTW0PJk9rZ1SibaBjQySKBh0TwV0h/VeIp0YYOcaW1aU1K5p3RRt0U7gbJYlp6El+ pxG6P1Pwmi0rNJ8LjaFR/31+FCKYbwOL/yj7iP8M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe , Marek Majkowski Subject: [PATCH 5.15 32/96] io_uring/net: save msghdr->msg_control for retries Date: Mon, 26 Jun 2023 20:11:47 +0200 Message-ID: <20230626180748.286611678@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230626180746.943455203@linuxfoundation.org> References: <20230626180746.943455203@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: Jens Axboe Commit cac9e4418f4cbd548ccb065b3adcafe073f7f7d2 upstream. If the application sets ->msg_control and we have to later retry this command, or if it got queued with IOSQE_ASYNC to begin with, then we need to retain the original msg_control value. This is due to the net stack overwriting this field with an in-kernel pointer, to copy it in. Hitting that path for the second time will now fail the copy from user, as it's attempting to copy from a non-user address. Cc: stable@vger.kernel.org # 5.10+ Link: https://github.com/axboe/liburing/issues/880 Reported-and-tested-by: Marek Majkowski Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/io_uring.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -581,6 +581,7 @@ struct io_sr_msg { size_t len; size_t done_io; struct io_buffer *kbuf; + void __user *msg_control; }; struct io_open { @@ -4864,10 +4865,16 @@ static int io_setup_async_msg(struct io_ static int io_sendmsg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg) { + struct io_sr_msg *sr = &req->sr_msg; + int ret; + iomsg->msg.msg_name = &iomsg->addr; iomsg->free_iov = iomsg->fast_iov; - return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg, + ret = sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg, req->sr_msg.msg_flags, &iomsg->free_iov); + /* save msg_control as sys_sendmsg() overwrites it */ + sr->msg_control = iomsg->msg.msg_control; + return ret; } static int io_sendmsg_prep_async(struct io_kiocb *req) @@ -4924,6 +4931,8 @@ static int io_sendmsg(struct io_kiocb *r if (ret) return ret; kmsg = &iomsg; + } else { + kmsg->msg.msg_control = sr->msg_control; } flags = req->sr_msg.msg_flags;