From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:48795 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753356AbdIDK1E (ORCPT ); Mon, 4 Sep 2017 06:27:04 -0400 Subject: FAILED: patch "[PATCH] crypto: algif_skcipher - only call put_page on referenced and" failed to apply to 4.4-stable tree To: smueller@chronox.de, herbert@gondor.apana.org.au, stable@vger.kernel.org Cc: From: Date: Mon, 04 Sep 2017 12:27:07 +0200 Message-ID: <150452082712371@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From 445a582738de6802669aeed9c33ca406c23c3b1f Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Wed, 16 Aug 2017 11:56:24 +0200 Subject: [PATCH] crypto: algif_skcipher - only call put_page on referenced and used pages For asynchronous operation, SGs are allocated without a page mapped to them or with a page that is not used (ref-counted). If the SGL is freed, the code must only call put_page for an SG if there was a page assigned and ref-counted in the first place. This fixes a kernel crash when using io_submit with more than one iocb using the sendmsg and sendpage (vmsplice/splice) interface. Cc: Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index 43839b00fe6c..903605dbc1a5 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -87,8 +87,13 @@ static void skcipher_free_async_sgls(struct skcipher_async_req *sreq) } sgl = sreq->tsg; n = sg_nents(sgl); - for_each_sg(sgl, sg, n, i) - put_page(sg_page(sg)); + for_each_sg(sgl, sg, n, i) { + struct page *page = sg_page(sg); + + /* some SGs may not have a page mapped */ + if (page && page_ref_count(page)) + put_page(page); + } kfree(sreq->tsg); }