From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE488C388F7 for ; Tue, 3 Nov 2020 21:54:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F70622403 for ; Tue, 3 Nov 2020 21:54:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604440480; bh=ntqQHSCvw4gPTX8zPXR8IMcXwra6zzoLk7qKbdD1KS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=n3ZQt9HUasI+rxYZmvAJzpELWQTD3tPi70QTFNl3kGE71YUwjVWKMRSztxnswLjdD QYgO9dhUFqJDdFnju3YeUtYuRSMNdxINBcMlwSi+TALS7XHXZRteaeq+pJHo93vYkq A8+ze3FPOBg6rEFsoTTnramaLgDoH1HLbvfc6PgA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731445AbgKCVyj (ORCPT ); Tue, 3 Nov 2020 16:54:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:33348 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730997AbgKCUpR (ORCPT ); Tue, 3 Nov 2020 15:45:17 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 64730223C6; Tue, 3 Nov 2020 20:45:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436316; bh=ntqQHSCvw4gPTX8zPXR8IMcXwra6zzoLk7qKbdD1KS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A0OiKJhkv0nEMxKZ1O5CeEabRkscO96MU1J+HrTNReUrraLtm0EJFp7dqcoe6u/10 T4IGkPr0X/CXWL2itOx0ZenEuW3dhGSPGVFH35ybmlq8aXdAgwAaLywxweSyzt3M+0 w+P7Kb2FX8Avj7TZ6H8Z2LjroPIE7Ue/wKiKMSbw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bart Van Assche , Douglas Gilbert , Jens Axboe , Sasha Levin Subject: [PATCH 5.9 180/391] sgl_alloc_order: fix memory leak Date: Tue, 3 Nov 2020 21:33:51 +0100 Message-Id: <20201103203359.018184395@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203348.153465465@linuxfoundation.org> References: <20201103203348.153465465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Douglas Gilbert [ Upstream commit b2a182a40278bc5849730e66bca01a762188ed86 ] sgl_alloc_order() can fail when 'length' is large on a memory constrained system. When order > 0 it will potentially be making several multi-page allocations with the later ones more likely to fail than the earlier one. So it is important that sgl_alloc_order() frees up any pages it has obtained before returning NULL. In the case when order > 0 it calls the wrong free page function and leaks. In testing the leak was sufficient to bring down my 8 GiB laptop with OOM. Reviewed-by: Bart Van Assche Signed-off-by: Douglas Gilbert Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- lib/scatterlist.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 5d63a8857f361..c448642e0f786 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -514,7 +514,7 @@ struct scatterlist *sgl_alloc_order(unsigned long long length, elem_len = min_t(u64, length, PAGE_SIZE << order); page = alloc_pages(gfp, order); if (!page) { - sgl_free(sgl); + sgl_free_order(sgl, order); return NULL; } -- 2.27.0