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 90022BA4F for ; Tue, 7 Mar 2023 19:09:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAB5CC433D2; Tue, 7 Mar 2023 19:09:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678216156; bh=HZ0EYaK3PJeEE7H8u20R0DtG4UMkUwdEleOKACvkzow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r8ZSH7mHMvAi+PzMQvoVXKWy5atseLmvVao19jxTBsYHHqKl7OVJa9oEDLtuBASVn Pkw8cMGDt/YxOdLNyFUOLJUa/l/2LpdpuovqWQISNqcT/rGbR7E7TT6jLjvlLSrnm4 Yv137ZOl9x1aWfIGWE1KYUvyo5IW2YljrJRTKefE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pavel Begunkov , Jens Axboe Subject: [PATCH 5.15 493/567] io_uring/rsrc: disallow multi-source reg buffers Date: Tue, 7 Mar 2023 18:03:49 +0100 Message-Id: <20230307165927.314981217@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307165905.838066027@linuxfoundation.org> References: <20230307165905.838066027@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: Pavel Begunkov commit edd478269640b360c6f301f2baa04abdda563ef3 upstream. If two or more mappings go back to back to each other they can be passed into io_uring to be registered as a single registered buffer. That would even work if mappings came from different sources, e.g. it's possible to mix in this way anon pages and pages from shmem or hugetlb. That is not a problem but it'd rather be less prone if we forbid such mixing. Cc: Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/io_uring.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -9228,14 +9228,17 @@ static int io_sqe_buffer_register(struct pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM, pages, vmas); if (pret == nr_pages) { + struct file *file = vmas[0]->vm_file; + /* don't support file backed memory */ for (i = 0; i < nr_pages; i++) { - struct vm_area_struct *vma = vmas[i]; - - if (vma_is_shmem(vma)) + if (vmas[i]->vm_file != file) { + ret = -EINVAL; + break; + } + if (!file) continue; - if (vma->vm_file && - !is_file_hugepages(vma->vm_file)) { + if (!vma_is_shmem(vmas[i]) && !is_file_hugepages(file)) { ret = -EOPNOTSUPP; break; }