From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57162 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750907AbdIEGWX (ORCPT ); Tue, 5 Sep 2017 02:22:23 -0400 Subject: Patch "crypto: algif_skcipher - only call put_page on referenced and used pages" has been added to the 4.4-stable tree To: smueller@chronox.de, gregkh@linuxfoundation.org, herbert@gondor.apana.org.au Cc: , From: Date: Tue, 05 Sep 2017 08:22:23 +0200 Message-ID: <150459254318749@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: This is a note to let you know that I've just added the patch titled crypto: algif_skcipher - only call put_page on referenced and used pages to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: crypto-algif_skcipher-only-call-put_page-on-referenced-and-used-pages.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 445a582738de6802669aeed9c33ca406c23c3b1f Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Wed, 16 Aug 2017 11:56:24 +0200 Subject: crypto: algif_skcipher - only call put_page on referenced and used pages From: Stephan Mueller commit 445a582738de6802669aeed9c33ca406c23c3b1f upstream. 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. Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/algif_skcipher.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -86,8 +86,13 @@ static void skcipher_free_async_sgls(str } 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 && atomic_read(&page->_count)) + put_page(page); + } kfree(sreq->tsg); } Patches currently in stable-queue which might be from smueller@chronox.de are queue-4.4/crypto-algif_skcipher-only-call-put_page-on-referenced-and-used-pages.patch