From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Date: Fri, 14 Jun 2019 05:03:45 +0000 Subject: Re: [PATCH] mm/slab: restore IRQs in kfree() Message-Id: <201906132202.9BF49E6B@keescook> List-Id: References: <20190613065637.GE16334@mwanda> In-Reply-To: <20190613065637.GE16334@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter , Andrew Morton Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm@kvack.org, kernel-janitors@vger.kernel.org On Thu, Jun 13, 2019 at 09:56:37AM +0300, Dan Carpenter wrote: > We added a new return here but we need to restore the IRQs before > we leave. > > Fixes: 4f5d94fd4ed5 ("mm/slab: sanity-check page type when looking up cache") > Signed-off-by: Dan Carpenter Oh yes! Thank you for that catch! Andrew, if you haven't already, can you pick this up? Thanks! -Kees > --- > mm/slab.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/mm/slab.c b/mm/slab.c > index 9e3eee5568b6..db01e9aae31b 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -3745,8 +3745,10 @@ void kfree(const void *objp) > local_irq_save(flags); > kfree_debugcheck(objp); > c = virt_to_cache(objp); > - if (!c) > + if (!c) { > + local_irq_restore(flags); > return; > + } > debug_check_no_locks_freed(objp, c->object_size); > > debug_check_no_obj_freed(objp, c->object_size); > -- > 2.20.1 > -- Kees Cook 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 BB8F3C31E44 for ; Fri, 14 Jun 2019 05:03:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 597DE21473 for ; Fri, 14 Jun 2019 05:03:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="bJWdlpRR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 597DE21473 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A9FDB8E0003; Fri, 14 Jun 2019 01:03:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A50FF8E0002; Fri, 14 Jun 2019 01:03:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9661A8E0003; Fri, 14 Jun 2019 01:03:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id 6299B8E0002 for ; Fri, 14 Jun 2019 01:03:49 -0400 (EDT) Received: by mail-pf1-f198.google.com with SMTP id 145so909848pfv.18 for ; Thu, 13 Jun 2019 22:03:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:date:from:to:cc:subject :message-id:references:mime-version:content-disposition:in-reply-to; bh=vzWNfLLLAeGdx7iHT9n2mvQxcG6bp4wZCUilrxRaOBg=; b=rT+d6PpTBVmfqu68+0nQnmfme88CKjs16jX0OnVJtVBUlJUGJ6lthqph5UwPED6Tgl jkOdyW1uMNLO03z4PQIJ9p05QjED9IrYYLa7SZgUSfeRAoCBeVlpeywmMkHd7gLUENbM QzkkZMX3YUj3F5eG53N7QezuGpVpZu46HQgmTqai/o7WGTTceYJiyPuucPGg81MIKbQ1 9vh13XEOOJIJ4APj2PxltbEqndCXi360mVMh+eqZhgwir0hISb0zbYbKKAPOCJpSBGPN CBrlBHFToWyEzD1TWmgePQlANmPY/k3WpKiXSszGj2gay/kxFziEaL7DmJ7A0qXKrHLB 3z1g== X-Gm-Message-State: APjAAAWnOzP3zobKRx32itpGuufZJjut5LogAevSxAcbcSmyZTvVjrX5 zdIVQ72OXfgGRf1kstglwiCRCfpvp4b74hAsZDkOiB2Oteaz7IH0tpvsiz5ErWoGWA9L8aBMLPp nZkgUzGGf6eQByya+t0arieX9h1rD9jfAupk4FrHkK38tISCl3nRJRKCYFg18d9WRQw== X-Received: by 2002:a63:161b:: with SMTP id w27mr33505740pgl.338.1560488628833; Thu, 13 Jun 2019 22:03:48 -0700 (PDT) X-Received: by 2002:a63:161b:: with SMTP id w27mr33505676pgl.338.1560488627852; Thu, 13 Jun 2019 22:03:47 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1560488627; cv=none; d=google.com; s=arc-20160816; b=V5jHfE8U0PyGKM0INrI9/MJmL6ywiQI5n/Q+TqWEUBiT8Gwk+YJuEFvIxAclOZZFkd UuOFpYYVJsBT33LtdcQQvZkVda+MELtz/AALkCtDnlWQNYCJMV0eaaSOJJopI8zrXhf4 f7ry66U8tbcrUAnHRl90MZ2413jqthA8jAQs+UiGffQQ+sb1dDJ0jsNT1pSFazXcbWOm lE6ZRvFpz+QN+37S42ok2Q8MJTxJlTCorF3GdQsUmrlCCJgh8WpXAn8B0xW2EY9Oy3Jj z4duEWpJS7XsRMeW1a2hp0qQPDzdLQ/peQiXMHDPDzx5I8+d85tKxPbmAYbGPJirzdBK Cfqg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:dkim-signature; bh=vzWNfLLLAeGdx7iHT9n2mvQxcG6bp4wZCUilrxRaOBg=; b=IPnW//c/FSjwc/iE524Yvv3UlvgPXBSWhYWik3PHT8ARm+0cZnxdEeiJ1rr3ErJaLa y7x4i8OTLltHikzH1p7F04PXUiVktorTN5CB8dSI+oWIgz2+KoF1KBMB1zXII3FIe2ad RKCalX1Act/PbqhiI7JcHj8NR6hFSBfxjJjBCiU+P3Qs0mH9InPRK9APLphA7d3hUp8v qS6xmuBeZr8cPFV3NpKxVGgxjs46ttReNyH91ZgHA2yo+wuWc9BdFbrKYiQAVew4F9BW Uk88UoXJtps260C6hKjzFQ3eOoqWxUX7ST7fbfVs3ciGpmla2ewQt7x5/OVCoTK/unQs CZxw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=bJWdlpRR; spf=pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. 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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id d123sm1521005pfc.144.2019.06.13.22.03.46 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 13 Jun 2019 22:03:46 -0700 (PDT) Date: Thu, 13 Jun 2019 22:03:45 -0700 From: Kees Cook To: Dan Carpenter , Andrew Morton Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm@kvack.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] mm/slab: restore IRQs in kfree() Message-ID: <201906132202.9BF49E6B@keescook> References: <20190613065637.GE16334@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190613065637.GE16334@mwanda> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jun 13, 2019 at 09:56:37AM +0300, Dan Carpenter wrote: > We added a new return here but we need to restore the IRQs before > we leave. > > Fixes: 4f5d94fd4ed5 ("mm/slab: sanity-check page type when looking up cache") > Signed-off-by: Dan Carpenter Oh yes! Thank you for that catch! Andrew, if you haven't already, can you pick this up? Thanks! -Kees > --- > mm/slab.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/mm/slab.c b/mm/slab.c > index 9e3eee5568b6..db01e9aae31b 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -3745,8 +3745,10 @@ void kfree(const void *objp) > local_irq_save(flags); > kfree_debugcheck(objp); > c = virt_to_cache(objp); > - if (!c) > + if (!c) { > + local_irq_restore(flags); > return; > + } > debug_check_no_locks_freed(objp, c->object_size); > > debug_check_no_obj_freed(objp, c->object_size); > -- > 2.20.1 > -- Kees Cook